Add model manager extension type.

.forgejo/workflows/test.yaml

@@ -12,4 +12,5 @@ jobs:
         with:
           cache: "yarn"
       - run: yarn install
+      - run: yarn lint
       - run: yarn coverage

.prettierrc

@@ -0,0 +1,5 @@
+{
+	"useTabs": true,
+	"trailingComma": "all",
+	"bracketSpacing": false
+}

README.md

@@ -19,39 +19,49 @@
 </p>
 
 <p align="center">
-	<a href="https://www.npmjs.com/package/@sharkitek/core" target="_blank">
+	<img alt="Tests status" src="https://code.zeptotech.net/Sharkitek/Core/badges/workflows/test.yaml/badge.svg?branch=main" />
-		<img alt="Latest release" src="https://code.zeptotech.net/Sharkitek/Core/badges/release.svg" />
+	<a href="https://bundlephobia.com/package/@sharkitek/core" target="_blank">
+		<img alt="Bundle size" src="https://badgen.net/bundlephobia/minzip/@sharkitek/core" />
 	</a>
-	<img alt="Tests status" src="https://code.zeptotech.net/Sharkitek/Core/badges/workflows/test.yaml/badge.svg" />
+	<a href="https://www.npmjs.com/package/@sharkitek/core" target="_blank">
+		<img alt="Latest release" src="https://badgen.net/npm/v/@sharkitek/core" />
+	</a>
+	<a href="https://bundlephobia.com/package/@sharkitek/core" target="_blank">
+		<img alt="Bundle size" src="https://badgen.net/bundlephobia/dependency-count/@sharkitek/core" />
+	</a>
+	<img alt="Latest release" src="https://badgen.net/npm/types/@sharkitek/core" />
 </p>
 
 ## Introduction
 
 Sharkitek is a lightweight Javascript / TypeScript library designed to ease development of models.
 
+```shell
+yarn add @sharkitek/core
+```
+
 With Sharkitek, you define the architecture of your models by specifying their properties and their types.
 Then, you can use the defined methods like `serialize`, `parse`, `patch` or `serializeDiff`.
 
 ```typescript
-class Example
+class Example {
-{
+	id: number;
-	static model = defineModel({
+	name: string;
+}
+
+const ExampleModel = defineModel({
 	Class: Example,
 	properties: {
 		id: s.property.numeric(),
 		name: s.property.string(),
 	},
 	identifier: "id",
-	});
+});
-	
-	id: number;
-	name: string;
-}
 ```
 
 ## Quick start
 
-**Note**: by convention, we define our models in a `model` static variable in the model's class. It is a good way to keep your model declaration near the actual class, and its usage will be more natural.
+**Note**: we usually define our models in a `{ModelName}Model` variable next to the model's class.
 
 ### Model definition
 
@@ -59,9 +69,18 @@ class Example
 /**
  * A person.
  */
-class Person
+class Person {
-{
+	id: number;
-	static model = defineModel({
+	name: string;
+	email: string;
+	createdAt: Date;
+	active: boolean = true;
+}
+
+/**
+ * A person model manager.
+ */
+const PersonModel = defineModel({
 	Class: Person,
 	properties: {
 		id: s.property.numeric(),
@@ -71,39 +90,14 @@ class Person
 		active: s.property.boolean(),
 	},
 	identifier: "id",
-	});
+});
-	
-	id: number;
-	name: string;
-	email: string;
-	createdAt: Date;
-	active: boolean = true;
-}
 ```
 
 ```typescript
 /**
  * An article.
  */
-class Article
+class Article {
-{
-	static model = defineModel({
-		Class: Article,
-		properties: {
-			id: s.property.numeric(),
-			title: s.property.string(),
-			authors: s.property.array(s.property.model(Person)),
-			text: s.property.string(),
-			evaluation: s.property.decimal(),
-			tags: s.property.array(
-				s.property.object({
-					name: s.property.string(),
-				})
-			),
-		},
-		identifier: "id",
-	});
-	
 	id: number;
 	title: string;
 	authors: Person[] = [];
@@ -113,26 +107,48 @@ class Article
 		name: string;
 	}[];
 }
+
+/**
+ * An article model manager.
+ */
+const ArticleModel = defineModel({
+	Class: Article,
+	properties: {
+		id: s.property.numeric(),
+		title: s.property.string(),
+		authors: s.property.array(s.property.model(PersonModel)),
+		text: s.property.string(),
+		evaluation: s.property.decimal(),
+		tags: s.property.array(
+			s.property.object({
+				name: s.property.string(),
+			}),
+		),
+	},
+	identifier: "id",
+});
 ```
 
 ```typescript
 /**
  * A model with composite keys.
  */
-class CompositeKeys
+class CompositeKeys {
-{
+	id1: number;
-	static model = defineModel({
+	id2: string;
+}
+
+/**
+ * A composite keys model manager.
+ */
+const CompositeKeysModel = defineModel({
 	Class: CompositeKeys,
 	properties: {
 		id1: s.property.numeric(),
 		id2: s.property.string(),
 	},
 	identifier: ["id1", "id2"],
-	});
+});
-	
-	id1: number;
-	id2: string;
-}
 ```
 
 ### Model functions
@@ -146,14 +162,14 @@ instance.createdAt = new Date();
 instance.name = "John Doe";
 instance.email = "john@doe.test";
 instance.active = true;
-const serialized = Person.model.model(instance).serialize();
+const serialized = PersonModel.model(instance).serialize();
 console.log(serialized); // { id: 1, createdAt: "YYYY-MM-DDTHH:mm:ss.sssZ", name: "John Doe", email: "john@doe.test", active: true }
 ```
 
 #### Deserialization
 
 ```typescript
-const instance = Person.model.parse({
+const instance = PersonModel.parse({
 	id: 1,
 	createdAt: "2011-10-05T14:48:00.000Z",
 	name: "John Doe",
@@ -167,7 +183,7 @@ console.log(instance.createdAt instanceof Date); // true
 #### Patch
 
 ```typescript
-const instance = Person.model.parse({
+const instance = PersonModel.parse({
 	id: 1,
 	createdAt: "2011-10-05T14:48:00.000Z",
 	name: "John Doe",
@@ -178,9 +194,9 @@ const instance = Person.model.parse({
 instance.name = "Johnny";
 
 // Patch serialized only changed properties and the identifier.
-console.log(Person.model.model(instance).patch()); // { id: 1, name: "Johnny" }
+console.log(PersonModel.model(instance).patch()); // { id: 1, name: "Johnny" }
 // If you run it one more time, already patched properties will not be included again.
-console.log(Person.model.model(instance).patch()); // { id: 1 }
+console.log(PersonModel.model(instance).patch()); // { id: 1 }
 ```
 
 #### Identifier
@@ -189,7 +205,7 @@ console.log(Person.model.model(instance).patch()); // { id: 1 }
 const instance = new CompositeKeys();
 instance.id1 = 5;
 instance.id2 = "foo";
-const instanceIdentifier = CompositeKeys.model.model(instance).getIdentifier();
+const instanceIdentifier = CompositeKeysModel.model(instance).getIdentifier();
 console.log(instanceIdentifier); // [5, "foo"]
 ```
 
@@ -208,22 +224,22 @@ Sharkitek defines some basic types by default, in these classes:
 - `DateType`: date in the model, ISO formatted date in the serialized object.
 - `ArrayType`: array in the model, array in the serialized object.
 - `ObjectType`: object in the model, object in the serialized object.
+- `MapType`: map in the model, record object in the serialized object.
 - `ModelType`: instance of a specific class in the model, object in the serialized object.
 
 When you are defining a property of a Sharkitek model, you must provide its type by instantiating one of these classes.
 
 ```typescript
-class Example
+class Example {
-{
+	foo: string;
-	static model = defineModel({
+}
+
+const ExampleModel = defineModel({
 	Class: Example,
 	properties: {
 		foo: s.property.define(new StringType()),
 	},
-	});
+});
-	
-	foo: string;
-}
 ```
 
 To ease the use of these classes and reduce read complexity, properties of each type are easily definable with a function for each type.
@@ -235,22 +251,22 @@ To ease the use of these classes and reduce read complexity, properties of each
 - `DateType` => `s.property.date`
 - `ArrayType` => `s.property.array`
 - `ObjectType` => `s.property.object`
+- `MapType` => `s.property.map` or `s.property.stringMap`
 - `ModelType` => `s.property.model`
 
 Type implementers should provide a corresponding function for each defined type. They can even provide multiple functions or constants with predefined parameters. For example, we could define `s.property.stringArray()` which would be similar to `s.property.array(s.property.string())`.
 
 ```typescript
-class Example
+class Example {
-{
+	foo: string;
-	static model = defineModel({
+}
+
+const ExampleModel = defineModel({
 	Class: Example,
 	properties: {
 		foo: s.property.string(),
 	},
-	});
+});
-	
-	foo: string;
-}
 ```
 
 ### Models
@@ -263,6 +279,30 @@ Get a model class (which has all the sharkitek models' functions) from a model i
 const model = definedModel.model(modelInstance);
 ```
 
+#### `assign(object)`
+
+Assign fields from a provided object to the model instance properties. Fields which are not properties of the target model are silently ignored.
+
+```typescript
+const alteredModelInstance = definedModel.model(modelInstance).assign({
+	anyProperty: "foo",
+	anotherOne: true,
+	not_a_property: "will be ignored",
+});
+```
+
+#### `from(object)`
+
+Initialize a model instance and assign the provided fields to its properties. Fields which are not properties of the target model are silently ignored.
+
+```typescript
+const newModelInstance = definedModel.from({
+	anyProperty: "foo",
+	anotherOne: true,
+	not_a_property: "will be ignored",
+});
+```
+
 #### `serialize()`
 
 Serialize the model.

eslint.config.js

@@ -0,0 +1,23 @@
+import js from "@eslint/js";
+import globals from "globals";
+import tseslint from "typescript-eslint";
+import {defineConfig, globalIgnores} from "eslint/config";
+
+export default defineConfig([
+	globalIgnores([".yarn/**", "coverage/**", "lib/**"]),
+	{
+		files: ["**/*.{js,mjs,cjs,ts,mts,cts}"],
+		plugins: {js},
+		extends: ["js/recommended"],
+	},
+	{
+		files: ["**/*.{js,mjs,cjs,ts,mts,cts}"],
+		languageOptions: {globals: {...globals.browser, ...globals.node}},
+	},
+	tseslint.configs.recommended,
+	{
+		rules: {
+			"@typescript-eslint/no-explicit-any": "off",
+		},
+	},
+]);

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@sharkitek/core",
-	"version": "4.0.0",
+	"version": "4.1.0",
 	"description": "TypeScript library for well-designed model architectures.",
 	"keywords": [
 		"deserialization",
@@ -25,7 +25,9 @@
 	"scripts": {
 		"build": "tsc && vite build",
 		"test": "vitest",
-		"coverage": "vitest run --coverage"
+		"coverage": "vitest run --coverage",
+		"format": "prettier . --write",
+		"lint": "eslint"
 	},
 	"type": "module",
 	"source": "src/library.ts",
@@ -35,13 +37,18 @@
 		"lib/**/*"
 	],
 	"devDependencies": {
-		"@types/node": "^22.13.14",
+		"@eslint/js": "^9.30.0",
-		"@vitest/coverage-v8": "^3.0.9",
+		"@types/node": "^24.0.3",
+		"@vitest/coverage-v8": "^3.2.4",
+		"eslint": "^9.30.0",
+		"globals": "^16.2.0",
+		"prettier": "^3.6.0",
 		"ts-node": "^10.9.2",
-		"typescript": "^5.8.2",
+		"typescript": "^5.8.3",
-		"vite": "^6.2.3",
+		"typescript-eslint": "^8.35.0",
-		"vite-plugin-dts": "^4.5.3",
+		"vite": "^7.0.0",
-		"vitest": "^3.0.9"
+		"vite-plugin-dts": "^4.5.4",
+		"vitest": "^3.2.4"
 	},
-	"packageManager": "yarn@4.6.0"
+	"packageManager": "yarn@4.9.2"
 }

src/errors/index.ts

@@ -1,4 +1,3 @@
-
 export * from "./sharkitek-error";
 export * from "./type-error";
 export * from "./invalid-type-value-error";

src/errors/invalid-type-value-error.ts

@@ -4,10 +4,15 @@ import {Type} from "../model/types/type";
 /**
  * A Sharkitek type error when the passed value is invalid.
  */
-export class InvalidTypeValueError<SerializedType, ModelType> extends TypeError<SerializedType, ModelType>
+export class InvalidTypeValueError<SerializedType, ModelType> extends TypeError<
-{
+	SerializedType,
-	constructor(public type: Type<SerializedType, ModelType>, public value: any, message?: string)
+	ModelType
-	{
+> {
-		super(type, message ?? `${JSON.stringify(value)} is an invalid value`)
+	constructor(
+		public type: Type<SerializedType, ModelType>,
+		public value: any,
+		message?: string,
+	) {
+		super(type, message ?? `${JSON.stringify(value)} is an invalid value`);
 	}
 }

src/errors/sharkitek-error.ts

@@ -1,6 +1,4 @@
 /**
  * A Sharkitek error.
  */
-export class SharkitekError extends Error
+export class SharkitekError extends Error {}
-{
-}

src/errors/type-error.ts

@@ -4,10 +4,13 @@ import {Type} from "../model/types/type";
 /**
  * A Sharkitek type error.
  */
-export class TypeError<SerializedType, ModelType> extends SharkitekError
+export class TypeError<SerializedType, ModelType> extends SharkitekError {
-{
+	constructor(
-	constructor(public type: Type<SerializedType, ModelType>, message?: string)
+		public type: Type<SerializedType, ModelType>,
-	{
+		message?: string,
-		super(`Error in type ${type.constructor.name}${message ? `: ${message}` : ""}`);
+	) {
+		super(
+			`Error in type ${type.constructor.name}${message ? `: ${message}` : ""}`,
+		);
 	}
 }

src/library.ts

@@ -1,5 +1,5 @@
 import * as s from "./model";
 export * from "./model";
 export * from "./errors";
-export { s };
+export {s};
 export default s;

src/model/builder.ts

@@ -0,0 +1,77 @@
+import {
+	defineModel,
+	IdentifierDefinition,
+	ModelDefinition,
+	ModelShape,
+} from "./model";
+import {ConstructorOf} from "../utils";
+import {Definition} from "./property-definition";
+
+/**
+ * Model definition builder.
+ */
+export class ModelBuilder<
+	T extends object,
+	Shape extends ModelShape<T>,
+	Identifier extends IdentifierDefinition<T, Shape>,
+> {
+	/**
+	 * The built model definition.
+	 */
+	definition: ModelDefinition<T, Shape, Identifier>;
+
+	/**
+	 * Define a new property.
+	 * @param name The new property name.
+	 * @param definition The new property definition.
+	 */
+	property<
+		SerializedType,
+		PropertyName extends Exclude<keyof T, keyof Shape>,
+		PropertyDefinition extends Definition<SerializedType, T[PropertyName]>,
+	>(name: PropertyName, definition: PropertyDefinition) {
+		(this.definition.properties[name] as Definition<unknown, T[typeof name]>) =
+			definition;
+
+		return this as unknown as ModelBuilder<
+			T,
+			Shape & {[k in PropertyName]: PropertyDefinition},
+			Identifier
+		>;
+	}
+
+	/**
+	 * Set the model identifier.
+	 * @param identifier The new model identifier.
+	 */
+	identifier<NewIdentifier extends IdentifierDefinition<T, Shape>>(
+		identifier: NewIdentifier,
+	) {
+		(this.definition.identifier as unknown) = identifier;
+		return this as unknown as ModelBuilder<T, Shape, NewIdentifier>;
+	}
+
+	/**
+	 * Define a model using the current model definition.
+	 */
+	define() {
+		return defineModel(this.definition);
+	}
+}
+
+/**
+ * Initialize a model builder for the provided class.
+ * @param Class The class for which to build a model.
+ */
+export function newModel<
+	T extends object,
+	Shape extends ModelShape<T> = object,
+	Identifier extends IdentifierDefinition<T, Shape> = never,
+>(Class: ConstructorOf<T>): ModelBuilder<T, Shape, Identifier> {
+	const builder = new ModelBuilder<T, Shape, Identifier>();
+	builder.definition = {
+		Class,
+		properties: {} as Shape,
+	};
+	return builder;
+}

src/model/index.ts

@@ -1,8 +1,8 @@
-import * as property from "./properties";
+export * as property from "./properties";
-export {property};
 
 export * from "./model";
 export {Definition} from "./property-definition";
+export {newModel, ModelBuilder} from "./builder";
 
 export {ArrayType} from "./types/array";
 export {BooleanType} from "./types/boolean";

src/model/model.ts

@@ -1,5 +1,5 @@
 import {Definition, UnknownDefinition} from "./property-definition";
-import {ConstructorOf} from "../utils";
+import {ConstructorOf, Modify} from "../utils";
 
 /**
  * A model shape.
@@ -11,7 +11,10 @@ export type ModelShape<T extends object> = Partial<{
 /**
  * Properties values of a model based on its shape.
  */
-export type ModelPropertiesValues<T extends object, Shape extends ModelShape<T>> = {
+export type ModelPropertiesValues<
+	T extends object,
+	Shape extends ModelShape<T>,
+> = {
 	[k in keyof Shape]: Shape[k]["_sharkitek"];
 };
 
@@ -26,20 +29,39 @@ export type SerializedModel<T extends object, Shape extends ModelShape<T>> = {
  * This is an experimental serialized model type declaration.
  * @deprecated
  */
-type ExperimentalSerializedModel<T extends object, Shape extends ModelShape<T>>
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
-	= Omit<ExperimentalSerializedModelBase<T, Shape>, ExperimentalSerializedModelOptionalKeys<T, Shape>>
+type ExperimentalSerializedModel<
-	& Pick<Partial<ExperimentalSerializedModelBase<T, Shape>>, ExperimentalSerializedModelOptionalKeys<T, Shape>>;
+	T extends object,
-type ExperimentalSerializedModelBase<T extends object, Shape extends ModelShape<T>> = {
+	Shape extends ModelShape<T>,
+> = Omit<
+	ExperimentalSerializedModelBase<T, Shape>,
+	ExperimentalSerializedModelOptionalKeys<T, Shape>
+> &
+	Pick<
+		Partial<ExperimentalSerializedModelBase<T, Shape>>,
+		ExperimentalSerializedModelOptionalKeys<T, Shape>
+	>;
+type ExperimentalSerializedModelBase<
+	T extends object,
+	Shape extends ModelShape<T>,
+> = {
 	[k in keyof Shape]: Shape[k]["_serialized"];
 };
-type ExperimentalSerializedModelOptionalKeys<T extends object, Shape extends ModelShape<T>> = {
+type ExperimentalSerializedModelOptionalKeys<
-	[k in keyof Shape]: Shape[k]["_serialized"] extends undefined ? k : never
+	T extends object,
+	Shape extends ModelShape<T>,
+> = {
+	[k in keyof Shape]: Shape[k]["_serialized"] extends undefined ? k : never;
 }[keyof Shape];
 
 /**
  * A sharkitek model instance, with internal model state.
  */
-export type ModelInstance<T extends object, Shape extends ModelShape<T>, Identifier extends IdentifierDefinition<T, Shape>> = T & {
+export type ModelInstance<
+	T extends object,
+	Shape extends ModelShape<T>,
+	Identifier extends IdentifierDefinition<T, Shape>,
+> = T & {
 	/**
 	 * The Sharkitek model state.
 	 */
@@ -49,19 +71,34 @@ export type ModelInstance<T extends object, Shape extends ModelShape<T>, Identif
 /**
  * Identifier definition type.
  */
-export type IdentifierDefinition<T extends object, Shape extends ModelShape<T>> = (keyof Shape)|((keyof Shape)[]);
+export type IdentifierDefinition<
+	T extends object,
+	Shape extends ModelShape<T>,
+> = keyof Shape | (keyof Shape)[];
 
 /**
  * Identifier type.
  */
-export type IdentifierType<T extends object, Shape extends ModelShape<T>, Identifier extends IdentifierDefinition<T, Shape>>
+export type IdentifierType<
-	= Identifier extends keyof Shape ? Shape[Identifier]["_sharkitek"] : { [K in keyof Identifier]: Identifier[K] extends keyof Shape ? Shape[Identifier[K]]["_sharkitek"] : unknown };
+	T extends object,
+	Shape extends ModelShape<T>,
+	Identifier extends IdentifierDefinition<T, Shape>,
+> = Identifier extends keyof Shape
+	? Shape[Identifier]["_sharkitek"]
+	: {
+			[K in keyof Identifier]: Identifier[K] extends keyof Shape
+				? Shape[Identifier[K]]["_sharkitek"]
+				: unknown;
+		};
 
 /**
  * A model definition object.
  */
-export interface ModelDefinition<T extends object, Shape extends ModelShape<T>, Identifier extends IdentifierDefinition<T, Shape>>
+export interface ModelDefinition<
-{
+	T extends object,
+	Shape extends ModelShape<T>,
+	Identifier extends IdentifierDefinition<T, Shape>,
+> {
 	/**
 	 * Model class.
 	 */
@@ -83,8 +120,7 @@ export interface ModelDefinition<T extends object, Shape extends ModelShape<T>,
 /**
  * A model property.
  */
-export interface ModelProperty<T extends object, Shape extends ModelShape<T>>
+export interface ModelProperty<T extends object, Shape extends ModelShape<T>> {
-{
 	/**
 	 * Property name.
 	 */
@@ -104,13 +140,19 @@ export interface ModelProperty<T extends object, Shape extends ModelShape<T>>
 /**
  * Model properties iterator object.
  */
-export type ModelProperties<T extends object, Shape extends ModelShape<T>> = ModelProperty<T, Shape>[];
+export type ModelProperties<
+	T extends object,
+	Shape extends ModelShape<T>,
+> = ModelProperty<T, Shape>[];
 
 /**
  * A Sharkitek model state.
  */
-export class Model<T extends object, Shape extends ModelShape<T>, Identifier extends IdentifierDefinition<T, Shape>>
+export class Model<
-{
+	T extends object,
+	Shape extends ModelShape<T>,
+	Identifier extends IdentifierDefinition<T, Shape>,
+> {
 	/**
 	 * The model manager instance.
 	 */
@@ -144,15 +186,14 @@ export class Model<T extends object, Shape extends ModelShape<T>, Identifier ext
 		/**
 		 * The original serialized object, if there is one.
 		 */
-		serialized: SerializedModel<T, Shape>|null;
+		serialized: SerializedModel<T, Shape> | null;
 	};
 
 	/**
 	 * Initialize a new model state with the defined properties.
 	 * @param manager The model manager.
 	 */
-	constructor(manager: ModelManager<T, Shape, Identifier>)
+	constructor(manager: ModelManager<T, Shape, Identifier>) {
-	{
 		this.manager = manager;
 		this.definition = manager.definition;
 		this.properties = manager.properties;
@@ -161,11 +202,10 @@ export class Model<T extends object, Shape extends ModelShape<T>, Identifier ext
 	/**
 	 * Initialize the Sharkitek model state for a new instance.
 	 */
-	initInstance(): this
+	initInstance(): this {
-	{
 		return this.fromInstance(
 			// Initialize a new model instance.
-			new (this.definition.Class)()
+			new this.definition.Class(),
 		);
 	}
 
@@ -173,8 +213,7 @@ export class Model<T extends object, Shape extends ModelShape<T>, Identifier ext
 	 * Initialize the Sharkitek model state for the provided instance.
 	 * @param instance The model instance.
 	 */
-	fromInstance(instance: T): this
+	fromInstance(instance: T): this {
-	{
 		// Initialize the sharkitek model instance.
 		const sharkitekInstance = instance as ModelInstance<T, Shape, Identifier>;
 
@@ -188,8 +227,8 @@ export class Model<T extends object, Shape extends ModelShape<T>, Identifier ext
 		if (originalInstance)
 			// Share the same original values object.
 			this.original = originalInstance.original;
-		else
+		else {
-		{ // Initialize a new original values object, based on the current values of the instance.
+			// Initialize a new original values object, based on the current values of the instance.
 			this.original = {
 				properties: undefined,
 				serialized: null,
@@ -204,14 +243,14 @@ export class Model<T extends object, Shape extends ModelShape<T>, Identifier ext
 	 * Deserialize provided data to a new model instance.
 	 * @param serialized Serialized model.
 	 */
-	deserialize(serialized: SerializedModel<T, Shape>): this
+	deserialize(serialized: SerializedModel<T, Shape>): this {
-	{
 		// Initialize a new model instance.
 		this.initInstance();
 
-		for (const property of this.properties)
+		for (const property of this.properties) {
-		{ // For each defined model property, assigning its deserialized value.
+			// For each defined model property, assigning its deserialized value.
-			(this.instance[property.name as keyof T] as any) = property.definition.type.deserialize(serialized[property.name]);
+			(this.instance[property.name as keyof T] as any) =
+				property.definition.type.deserialize(serialized[property.name]);
 		}
 
 		// Reset original property values.
@@ -225,29 +264,31 @@ export class Model<T extends object, Shape extends ModelShape<T>, Identifier ext
 	/**
 	 * Get current model instance identifier.
 	 */
-	getIdentifier(): IdentifierType<T, Shape, Identifier>
+	getIdentifier(): IdentifierType<T, Shape, Identifier> {
-	{
+		if (Array.isArray(this.definition.identifier)) {
-		if (Array.isArray(this.definition.identifier))
+			// The identifier is composite, make an array of properties values.
-		{ // The identifier is composite, make an array of properties values.
+			return this.definition.identifier.map(
-			return this.definition.identifier.map(identifier => this.instance?.[identifier as keyof T]) as IdentifierType<T, Shape, Identifier>;
+				(identifier) => this.instance?.[identifier as keyof T],
-		}
+			) as IdentifierType<T, Shape, Identifier>;
-		else
+		} else {
-		{ // The identifier is a simple property, get its value.
+			// The identifier is a simple property, get its value.
-			return this.instance?.[this.definition.identifier as keyof Shape as keyof T] as IdentifierType<T, Shape, Identifier>;
+			return this.instance?.[
+				this.definition.identifier as keyof Shape as keyof T
+			] as IdentifierType<T, Shape, Identifier>;
 		}
 	}
 
 	/**
 	 * Get current model instance properties.
 	 */
-	getInstanceProperties(): ModelPropertiesValues<T, Shape>
+	getInstanceProperties(): ModelPropertiesValues<T, Shape> {
-	{
 		// Initialize an empty model properties object.
 		const instanceProperties: Partial<ModelPropertiesValues<T, Shape>> = {};
 
-		for (const property of this.properties)
+		for (const property of this.properties) {
-		{ // For each defined model property, adding it to the properties object.
+			// For each defined model property, adding it to the properties object.
-			instanceProperties[property.name] = this.instance?.[property.name as keyof T]; // keyof Shape is a subset of keyof T.
+			instanceProperties[property.name] =
+				this.instance?.[property.name as keyof T]; // keyof Shape is a subset of keyof T.
 		}
 
 		return instanceProperties as ModelPropertiesValues<T, Shape>; // Returning the properties object.
@@ -256,13 +297,12 @@ export class Model<T extends object, Shape extends ModelShape<T>, Identifier ext
 	/**
 	 * Serialize the model instance.
 	 */
-	serialize(): SerializedModel<T, Shape>
+	serialize(): SerializedModel<T, Shape> {
-	{
 		// Creating an empty serialized object.
 		const serializedObject: Partial<SerializedModel<T, Shape>> = {};
 
-		for (const property of this.properties)
+		for (const property of this.properties) {
-		{ // For each defined model property, adding it to the serialized object.
+			// For each defined model property, adding it to the serialized object.
 			serializedObject[property.name] = property.definition.type.serialize(
 				// keyof Shape is a subset of keyof T.
 				this.instance?.[property.name as keyof T],
@@ -275,19 +315,22 @@ export class Model<T extends object, Shape extends ModelShape<T>, Identifier ext
 	/**
 	 * Examine if the model is new (never deserialized) or not.
 	 */
-	isNew(): boolean
+	isNew(): boolean {
-	{
 		return !this.original.serialized;
 	}
 
 	/**
 	 * Examine if the model is dirty or not.
 	 */
-	isDirty(): boolean
+	isDirty(): boolean {
-	{
+		for (const property of this.properties) {
-		for (const property of this.properties)
+			// For each property, check if it is different.
-		{ // For each property, check if it is different.
+			if (
-			if (property.definition.type.hasChanged(this.original.properties?.[property.name], this.instance?.[property.name as keyof T]))
+				property.definition.type.hasChanged(
+					this.original.properties?.[property.name],
+					this.instance?.[property.name as keyof T],
+				)
+			)
 				// There is a difference: the model is dirty.
 				return true;
 		}
@@ -299,19 +342,23 @@ export class Model<T extends object, Shape extends ModelShape<T>, Identifier ext
 	/**
 	 * Serialize the difference between current model state and the original one.
 	 */
-	serializeDiff(): Partial<SerializedModel<T, Shape>>
+	serializeDiff(): Partial<SerializedModel<T, Shape>> {
-	{
 		// Creating an empty serialized object.
 		const serializedObject: Partial<SerializedModel<T, Shape>> = {};
 
-		for (const property of this.properties)
+		for (const property of this.properties) {
-		{ // For each defined model property, adding it to the serialized object if it has changed or if it is in the identifier.
+			// For each defined model property, adding it to the serialized object if it has changed or if it is in the identifier.
 			const instancePropValue = this.instance?.[property.name as keyof T]; // keyof Shape is a subset of keyof T.
 			if (
 				property.identifier ||
-				property.definition.type.hasChanged(this.original.properties?.[property.name], instancePropValue)
+				property.definition.type.hasChanged(
-			) // The property is part of the identifier or its value has changed.
+					this.original.properties?.[property.name],
-				serializedObject[property.name] = property.definition.type.serializeDiff(instancePropValue);
+					instancePropValue,
+				)
+			)
+				// The property is part of the identifier or its value has changed.
+				serializedObject[property.name] =
+					property.definition.type.serializeDiff(instancePropValue);
 		}
 
 		return serializedObject; // Returning the serialized object.
@@ -320,13 +367,13 @@ export class Model<T extends object, Shape extends ModelShape<T>, Identifier ext
 	/**
 	 * Set current model properties as original values.
 	 */
-	resetDiff(): void
+	resetDiff(): void {
-	{
 		this.original.properties = {};
-		for (const property of this.properties)
+		for (const property of this.properties) {
-		{ // For each property, set its original value to the current property value.
+			// For each property, set its original value to the current property value.
 			const instancePropValue = this.instance?.[property.name as keyof T];
-			this.original.properties[property.name] = property.definition.type.clone(instancePropValue);
+			this.original.properties[property.name] =
+				property.definition.type.clone(instancePropValue);
 			property.definition.type.resetDiff(instancePropValue);
 		}
 	}
@@ -335,8 +382,7 @@ export class Model<T extends object, Shape extends ModelShape<T>, Identifier ext
 	 * Get difference between original values and current ones, then reset it.
 	 * Similar to call `serializeDiff()` then `resetDiff()`.
 	 */
-	patch(): Partial<SerializedModel<T, Shape>>
+	patch(): Partial<SerializedModel<T, Shape>> {
-	{
 		// Get the difference.
 		const diff = this.serializeDiff();
 
@@ -349,32 +395,36 @@ export class Model<T extends object, Shape extends ModelShape<T>, Identifier ext
 	/**
 	 * Clone the model instance.
 	 */
-	clone(): ModelInstance<T, Shape, Identifier>
+	clone(): ModelInstance<T, Shape, Identifier> {
-	{
 		// Initialize a new instance for the clone.
 		const cloned = this.manager.model();
 
 		// Clone every value of the model instance.
-		for (const [key, value] of Object.entries(this.instance) as [keyof T, unknown][])
+		for (const [key, value] of Object.entries(this.instance) as [
-		{ // For each [key, value], clone the value and put it in the cloned instance.
+			keyof T,
+			unknown,
+		][]) {
+			// For each [key, value], clone the value and put it in the cloned instance.
 
 			// Do not clone ourselves.
 			if (key == "_sharkitek") continue;
 
-			if (this.definition.properties[key])
+			if (this.definition.properties[key]) {
-			{ // The current key is a defined property, clone using the defined type.
+				// The current key is a defined property, clone using the defined type.
-				(cloned.instance[key] as any) = (this.definition.properties[key] as UnknownDefinition).type.clone(value);
+				(cloned.instance[key] as any) = (
-			}
+					this.definition.properties[key] as UnknownDefinition
-			else
+				).type.clone(value);
-			{ // Not a property, cloning the raw value.
+			} else {
+				// Not a property, cloning the raw value.
 				(cloned.instance[key] as any) = structuredClone(value);
 			}
 		}
 
 		// Clone original properties.
-		for (const property of this.properties)
+		for (const property of this.properties) {
-		{ // For each property, clone its original value.
+			// For each property, clone its original value.
-			cloned.original.properties[property.name] = property.definition.type.clone(this.original.properties[property.name]);
+			cloned.original.properties[property.name] =
+				property.definition.type.clone(this.original.properties[property.name]);
 		}
 
 		// Clone original serialized.
@@ -382,15 +432,78 @@ export class Model<T extends object, Shape extends ModelShape<T>, Identifier ext
 
 		return cloned.instance; // Returning the cloned instance.
 	}
+
+	/**
+	 * Assign the provided fields to existing properties.
+	 * Fields that cannot be matched to existing properties are silently ignored.
+	 * @param fields The fields to assign to the model.
+	 */
+	assign(
+		fields: Partial<ModelPropertiesValues<T, Shape>> & {[field: string]: any},
+	): ModelInstance<T, Shape, Identifier> {
+		for (const field in fields) {
+			// For each field, if it's a property, assign its value.
+			if ((this.definition.properties as any)?.[field])
+				// Set the instance value.
+				this.instance[field as keyof T] = fields[field];
+		}
+		return this.instance;
+	}
+
+	/**
+	 * Apply a patch to the model instance. All known fields will be deserialized and assigned to the properties.
+	 * @param patch The patch object to apply.
+	 * @param updateOriginals Indicates if the original properties values must be updated or not. By default, they are reset.
+	 */
+	applyPatch(
+		patch: SerializedModel<T, Shape>,
+		updateOriginals: boolean = true,
+	): ModelInstance<T, Shape, Identifier> {
+		if (updateOriginals) {
+			// If serialized original is null and we need to update it, initialize it.
+			this.original.serialized = this.serialize();
+		}
+
+		for (const serializedField in patch) {
+			// For each field, if it's a property, assign its value.
+			// Get the property definition.
+			const property =
+				this.definition.properties[serializedField as keyof Shape];
+			if (property) {
+				// Found a matching model property, assigning its deserialized value.
+				(this.instance[serializedField as keyof Shape as keyof T] as any) = (
+					property as UnknownDefinition
+				).type.applyPatch(
+					this.instance[serializedField as keyof Shape as keyof T],
+					patch[serializedField],
+					updateOriginals,
+				);
+
+				if (updateOriginals) {
+					// Update original values.
+					// Set original property value.
+					(this.original.properties[serializedField] as any) = (
+						property as UnknownDefinition
+					).type.clone(
+						this.instance[serializedField as keyof Shape as keyof T],
+					);
+					// Set original serialized value.
+					this.original.serialized[serializedField] = patch[serializedField];
+				}
+			}
+		}
+		return this.instance;
+	}
 }
 
-
-
 /**
  * A model manager, created from a model definition.
  */
-export class ModelManager<T extends object, Shape extends ModelShape<T>, Identifier extends IdentifierDefinition<T, Shape>>
+export class ModelManager<
-{
+	T extends object,
+	Shape extends ModelShape<T>,
+	Identifier extends IdentifierDefinition<T, Shape>,
+> {
 	/**
 	 * Defined properties.
 	 */
@@ -400,8 +513,9 @@ export class ModelManager<T extends object, Shape extends ModelShape<T>, Identif
 	 * Initialize a model manager from a model definition.
 	 * @param definition The model definition.
 	 */
-	constructor(public readonly definition: ModelDefinition<T, Shape, Identifier>)
+	constructor(
-	{
+		public readonly definition: ModelDefinition<T, Shape, Identifier>,
+	) {
 		this.initProperties();
 	}
 
@@ -409,23 +523,22 @@ export class ModelManager<T extends object, Shape extends ModelShape<T>, Identif
 	 * Initialize properties iterator from current definition.
 	 * @protected
 	 */
-	protected initProperties(): void
+	protected initProperties(): void {
-	{
 		// Build an array of model properties from the definition.
 		this.properties = [];
-		for (const propertyName in this.definition.properties)
+		for (const propertyName in this.definition.properties) {
-		{ // For each property, build a model property object.
+			// For each property, build a model property object.
 			this.properties.push({
 				name: propertyName,
 				definition: this.definition.properties[propertyName],
 				// Find out if the current property is part of the identifier.
-				identifier: (
+				identifier: Array.isArray(this.definition.identifier)
-					Array.isArray(this.definition.identifier)
+					? // The identifier is an array, the property must be in the array.
-						// The identifier is an array, the property must be in the array.
+						this.definition.identifier.includes(
-						? this.definition.identifier.includes(propertyName as keyof Shape as keyof T)
+							propertyName as keyof Shape as keyof T,
-						// The identifier is a single string, the property must be the defined identifier.
+						)
-						: (this.definition.identifier == propertyName as keyof Shape)
+					: // The identifier is a single string, the property must be the defined identifier.
-				),
+						this.definition.identifier == (propertyName as keyof Shape),
 			} as ModelProperty<T, Shape>);
 		}
 	}
@@ -434,49 +547,121 @@ export class ModelManager<T extends object, Shape extends ModelShape<T>, Identif
 	 * Get the model state of the provided model instance.
 	 * @param instance The model instance for which to get its state. NULL or undefined to create a new one.
 	 */
-	model(instance: T|ModelInstance<T, Shape, Identifier>|null = null): Model<T, Shape, Identifier>
+	model(
-	{ // Get the instance model state if there is one, or initialize a new one.
+		instance: T | ModelInstance<T, Shape, Identifier> | null = null,
+	): Model<T, Shape, Identifier> {
+		// Get the instance model state if there is one, or initialize a new one.
 		if (instance)
 			// There is an instance, create a model from it.
-			return ((instance as ModelInstance<T, Shape, Identifier>)?._sharkitek ?? (new Model<T, Shape, Identifier>(this))).fromInstance(instance);
+			return (
+				(instance as ModelInstance<T, Shape, Identifier>)?._sharkitek ??
+				new Model<T, Shape, Identifier>(this)
+			).fromInstance(instance);
 		else
 			// No instance, initialize a new one.
-			return (new Model<T, Shape, Identifier>(this)).initInstance();
+			return new Model<T, Shape, Identifier>(this).initInstance();
+	}
+
+	/**
+	 * Initialize a new model instance with the provided object properties values.
+	 * Fields that cannot be matched to existing properties are silently ignored.
+	 * @param fields
+	 */
+	from(
+		fields: Partial<ModelPropertiesValues<T, Shape>> & {[field: string]: any},
+	): ModelInstance<T, Shape, Identifier> {
+		return this.model().assign(fields);
 	}
 
 	/**
 	 * Parse the serialized model object to a new model instance.
 	 * @param serialized The serialized model object.
 	 */
-	parse(serialized: SerializedModel<T, Shape>): ModelInstance<T, Shape, Identifier>
+	parse(
-	{
+		serialized: SerializedModel<T, Shape>,
+	): ModelInstance<T, Shape, Identifier> {
 		return this.model().deserialize(serialized).instance;
 	}
 }
 
+/**
+ * A model manager extension is a mixin, building a new model manager class with extended capabilities.
+ * @see https://www.typescriptlang.org/docs/handbook/mixins.html
+ */
+export type ModelManagerExtension<
+	Extension extends object,
+	T extends object,
+	Shape extends ModelShape<T>,
+	Identifier extends IdentifierDefinition<T, Shape>,
+> = (
+	modelManager: ModelManager<T, Shape, Identifier>,
+) => ModelManager<T, Shape, Identifier> & Extension;
+
 /**
  * Define a new model.
  * @param definition The model definition object.
  */
-export function defineModel<T extends object, Shape extends ModelShape<T>, Identifier extends IdentifierDefinition<T, Shape>>(
+export function defineModel<
-	definition: ModelDefinition<T, Shape, Identifier>
+	T extends object,
-)
+	Shape extends ModelShape<T>,
-{
+	Identifier extends IdentifierDefinition<T, Shape>,
+>(definition: ModelDefinition<T, Shape, Identifier>) {
 	return new ModelManager<T, Shape, Identifier>(definition);
 }
 
+/**
+ * Define a new model, extending an existing one.
+ * @param extendedModel The extended model manager instance.
+ * @param definition The extension of the model definition object.
+ */
+export function extend<
+	ExtT extends object,
+	ExtShape extends ModelShape<ExtT>,
+	ExtIdentifier extends IdentifierDefinition<ExtT, ExtShape>,
+	T extends ExtT,
+	Shape extends ModelShape<T>,
+	Identifier extends IdentifierDefinition<T, Shape>,
+	ResIdentifier extends IdentifierDefinition<T, ResShape>,
+	ResShape extends ModelShape<T> = Modify<ExtShape, Shape>,
+>(
+	extendedModel: ModelManager<ExtT, ExtShape, ExtIdentifier>,
+	definition: ModelDefinition<T, Shape, Identifier>,
+) {
+	const {properties: extendedProperties, ...overridableDefinition} =
+		extendedModel.definition;
+	const {properties: propertiesExtension, ...definitionExtension} = definition;
+	return new ModelManager({
+		...overridableDefinition,
+		...definitionExtension,
+		properties: {
+			...extendedProperties,
+			...propertiesExtension,
+		},
+	}) as unknown as ModelManager<T, ResShape, ResIdentifier>;
+}
+
 /**
  * A generic model manager for a provided model type, to use in circular dependencies.
  */
-export type GenericModelManager<T extends object> = ModelManager<T, ModelShape<T>, IdentifierDefinition<T, ModelShape<T>>>;
+export type GenericModelManager<T extends object> = ModelManager<
+	T,
+	ModelShape<T>,
+	IdentifierDefinition<T, ModelShape<T>>
+>;
 
 /**
  * Function to get a model manager lazily.
  */
-export type LazyModelManager<T extends object, Shape extends ModelShape<T>, Identifier extends IdentifierDefinition<T, Shape>>
+export type LazyModelManager<
-	= (() => ModelManager<T, Shape, Identifier>);
+	T extends object,
+	Shape extends ModelShape<T>,
+	Identifier extends IdentifierDefinition<T, Shape>,
+> = () => ModelManager<T, Shape, Identifier>;
 /**
  * A model manager definition that can be lazy.
  */
-export type DeclaredModelManager<T extends object, Shape extends ModelShape<T>, Identifier extends IdentifierDefinition<T, Shape>>
+export type DeclaredModelManager<
-	= ModelManager<T, Shape, Identifier>|LazyModelManager<T, Shape, Identifier>;
+	T extends object,
+	Shape extends ModelShape<T>,
+	Identifier extends IdentifierDefinition<T, Shape>,
+> = ModelManager<T, Shape, Identifier> | LazyModelManager<T, Shape, Identifier>;

src/model/properties.ts

@@ -8,3 +8,5 @@ export {model} from "./types/model";
 export {numeric} from "./types/numeric";
 export {object} from "./types/object";
 export {string} from "./types/string";
+export {map} from "./types/map";
+export {stringMap} from "./types/map";

src/model/property-definition.ts

@@ -3,8 +3,7 @@ import {Type} from "./types/type";
 /**
  * Property definition class.
  */
-export class Definition<SerializedType, ModelType>
+export class Definition<SerializedType, ModelType> {
-{
 	readonly _sharkitek: ModelType;
 	readonly _serialized: SerializedType;
 
@@ -12,8 +11,7 @@ export class Definition<SerializedType, ModelType>
 	 * Create a property definer instance.
 	 * @param type Property type.
 	 */
-	constructor(public readonly type: Type<SerializedType, ModelType>)
+	constructor(public readonly type: Type<SerializedType, ModelType>) {}
-	{}
 }
 
 /**
@@ -30,7 +28,8 @@ export type AnyDefinition = Definition<any, any>;
  * New definition of a property of the given type.
  * @param type Type of the property to define.
  */
-export function define<SerializedType, ModelType>(type: Type<SerializedType, ModelType>): Definition<SerializedType, ModelType>
+export function define<SerializedType, ModelType>(
-{
+	type: Type<SerializedType, ModelType>,
+): Definition<SerializedType, ModelType> {
 	return new Definition(type);
 }

src/model/types/array.ts

@@ -5,56 +5,70 @@ import {InvalidTypeValueError} from "../../errors";
 /**
  * Type of an array of values.
  */
-export class ArrayType<SerializedValueType, SharkitekValueType> extends Type<SerializedValueType[], SharkitekValueType[]>
+export class ArrayType<SerializedValueType, SharkitekValueType> extends Type<
-{
+	SerializedValueType[],
+	SharkitekValueType[]
+> {
 	/**
 	 * Initialize a new array type of a Sharkitek model property.
 	 * @param valueDefinition Definition the array values.
 	 */
-	constructor(protected valueDefinition: Definition<SerializedValueType, SharkitekValueType>)
+	constructor(
-	{
+		protected valueDefinition: Definition<
+			SerializedValueType,
+			SharkitekValueType
+		>,
+	) {
 		super();
 	}
 
-	serialize(value: SharkitekValueType[]|null|undefined): SerializedValueType[]|null|undefined
+	serialize(
-	{
+		value: SharkitekValueType[] | null | undefined,
+	): SerializedValueType[] | null | undefined {
 		if (value === undefined) return undefined;
 		if (value === null) return null;
 
-		if (!Array.isArray(value)) throw new InvalidTypeValueError(this, value, "value must be an array");
+		if (!Array.isArray(value))
+			throw new InvalidTypeValueError(this, value, "value must be an array");
 
-		return value.map((value) => (
+		return value.map((value) =>
 			// Serializing each value of the array.
-			this.valueDefinition.type.serialize(value)
+			this.valueDefinition.type.serialize(value),
-		));
+		);
 	}
 
-	deserialize(value: SerializedValueType[]|null|undefined): SharkitekValueType[]|null|undefined
+	deserialize(
-	{
+		value: SerializedValueType[] | null | undefined,
+	): SharkitekValueType[] | null | undefined {
 		if (value === undefined) return undefined;
 		if (value === null) return null;
 
-		if (!Array.isArray(value)) throw new InvalidTypeValueError(this, value, "value must be an array");
+		if (!Array.isArray(value))
+			throw new InvalidTypeValueError(this, value, "value must be an array");
 
-		return value.map((serializedValue) => (
+		return value.map((serializedValue) =>
 			// Deserializing each value of the array.
-			this.valueDefinition.type.deserialize(serializedValue)
+			this.valueDefinition.type.deserialize(serializedValue),
-		));
+		);
 	}
 
-	serializeDiff(value: SharkitekValueType[]|null|undefined): SerializedValueType[]|null|undefined
+	serializeDiff(
-	{
+		value: SharkitekValueType[] | null | undefined,
+	): SerializedValueType[] | null | undefined {
 		if (value === undefined) return undefined;
 		if (value === null) return null;
 
-		if (!Array.isArray(value)) throw new InvalidTypeValueError(this, value, "value must be an array");
+		if (!Array.isArray(value))
+			throw new InvalidTypeValueError(this, value, "value must be an array");
 
 		// Serializing diff of all elements.
-		return value.map((value) => this.valueDefinition.type.serializeDiff(value) as SerializedValueType);
+		return value.map(
+			(value) =>
+				this.valueDefinition.type.serializeDiff(value) as SerializedValueType,
+		);
 	}
 
-	resetDiff(value: SharkitekValueType[]|null|undefined): void
+	resetDiff(value: SharkitekValueType[] | null | undefined): void {
-	{
 		// Do nothing if it is not an array.
 		if (!Array.isArray(value)) return;
 
@@ -62,16 +76,24 @@ export class ArrayType<SerializedValueType, SharkitekValueType> extends Type<Ser
 		value.forEach((value) => this.valueDefinition.type.resetDiff(value));
 	}
 
-	hasChanged(originalValue: SharkitekValueType[]|null|undefined, currentValue: SharkitekValueType[]|null|undefined): boolean
+	hasChanged(
-	{
+		originalValue: SharkitekValueType[] | null | undefined,
+		currentValue: SharkitekValueType[] | null | undefined,
+	): boolean {
 		// If any array length is different, arrays are different.
 		if (originalValue?.length != currentValue?.length) return true;
 		// If length is undefined, values are probably not arrays.
-		if (originalValue?.length == undefined) return super.hasChanged(originalValue, currentValue);
+		if (originalValue?.length == undefined)
+			return super.hasChanged(originalValue, currentValue);
 
-		for (const key of originalValue.keys())
+		for (const key of originalValue.keys()) {
-		{ // Check for any change for each value in the array.
+			// Check for any change for each value in the array.
-			if (this.valueDefinition.type.hasChanged(originalValue[key], currentValue[key]))
+			if (
+				this.valueDefinition.type.hasChanged(
+					originalValue[key],
+					currentValue[key],
+				)
+			)
 				// The value has changed, the array is different.
 				return true;
 		}
@@ -79,16 +101,24 @@ export class ArrayType<SerializedValueType, SharkitekValueType> extends Type<Ser
 		return false; // No change detected.
 	}
 
-	serializedHasChanged(originalValue: SerializedValueType[] | null | undefined, currentValue: SerializedValueType[] | null | undefined): boolean
+	serializedHasChanged(
-	{
+		originalValue: SerializedValueType[] | null | undefined,
+		currentValue: SerializedValueType[] | null | undefined,
+	): boolean {
 		// If any array length is different, arrays are different.
 		if (originalValue?.length != currentValue?.length) return true;
 		// If length is undefined, values are probably not arrays.
-		if (originalValue?.length == undefined) return super.serializedHasChanged(originalValue, currentValue);
+		if (originalValue?.length == undefined)
+			return super.serializedHasChanged(originalValue, currentValue);
 
-		for (const key of originalValue.keys())
+		for (const key of originalValue.keys()) {
-		{ // Check for any change for each value in the array.
+			// Check for any change for each value in the array.
-			if (this.valueDefinition.type.serializedHasChanged(originalValue[key], currentValue[key]))
+			if (
+				this.valueDefinition.type.serializedHasChanged(
+					originalValue[key],
+					currentValue[key],
+				)
+			)
 				// The value has changed, the array is different.
 				return true;
 		}
@@ -96,30 +126,62 @@ export class ArrayType<SerializedValueType, SharkitekValueType> extends Type<Ser
 		return false; // No change detected.
 	}
 
-	clone<T extends SharkitekValueType[]>(array: T|null|undefined): T
+	clone<T extends SharkitekValueType[]>(array: T | null | undefined): T {
-	{
 		// Handle NULL / undefined array.
 		if (!array) return super.clone(array);
 
-		if (!Array.isArray(array)) throw new InvalidTypeValueError(this, array, "value must be an array");
+		if (!Array.isArray(array))
+			throw new InvalidTypeValueError(this, array, "value must be an array");
 
 		// Initialize an empty array.
 		const cloned = [] as T;
 
-		for (const value of array)
+		for (const value of array) {
-		{ // Clone each value of the array.
+			// Clone each value of the array.
 			cloned.push(this.valueDefinition.type.clone(value));
 		}
 
 		return cloned; // Returning cloned array.
 	}
+
+	applyPatch<T extends SharkitekValueType[]>(
+		currentValue: T | null | undefined,
+		patchValue: SerializedValueType[] | null | undefined,
+		updateOriginals: boolean,
+	): T | null | undefined {
+		if (patchValue === undefined) return undefined;
+		if (patchValue === null) return null;
+
+		if (!Array.isArray(patchValue))
+			throw new InvalidTypeValueError(
+				this,
+				patchValue,
+				"value must be an array",
+			);
+
+		currentValue = Array.isArray(currentValue) ? currentValue : ([] as T);
+
+		for (let i = 0; i < patchValue.length; i++) {
+			// Apply the patch to all values of the array.
+			const patchedElement = this.valueDefinition.type.applyPatch(
+				currentValue?.[i],
+				patchValue[i],
+				updateOriginals,
+			);
+			if (i < currentValue.length) currentValue[i] = patchedElement;
+			else currentValue.push(patchedElement);
+		}
+
+		return currentValue;
+	}
 }
 
 /**
  * New array property definition.
  * @param valueDefinition Array values type definition.
  */
-export function array<SerializedValueType, SharkitekValueType>(valueDefinition: Definition<SerializedValueType, SharkitekValueType>): Definition<SerializedValueType[], SharkitekValueType[]>
+export function array<SerializedValueType, SharkitekValueType>(
-{
+	valueDefinition: Definition<SerializedValueType, SharkitekValueType>,
+): Definition<SerializedValueType[], SharkitekValueType[]> {
 	return define(new ArrayType(valueDefinition));
 }

src/model/types/boolean.ts

@@ -4,10 +4,8 @@ import {define, Definition} from "../property-definition";
 /**
  * Type of any boolean value.
  */
-export class BooleanType extends Type<boolean, boolean>
+export class BooleanType extends Type<boolean, boolean> {
-{
+	deserialize(value: boolean | null | undefined): boolean | null | undefined {
-	deserialize(value: boolean|null|undefined): boolean|null|undefined
-	{
 		// Keep NULL and undefined values.
 		if (value === undefined) return undefined;
 		if (value === null) return null;
@@ -15,8 +13,7 @@ export class BooleanType extends Type<boolean, boolean>
 		return !!value; // ensure bool type.
 	}
 
-	serialize(value: boolean|null|undefined): boolean|null|undefined
+	serialize(value: boolean | null | undefined): boolean | null | undefined {
-	{
 		// Keep NULL and undefined values.
 		if (value === undefined) return undefined;
 		if (value === null) return null;
@@ -28,15 +25,13 @@ export class BooleanType extends Type<boolean, boolean>
 /**
  * New boolean property definition.
  */
-export function boolean(): Definition<boolean, boolean>
+export function boolean(): Definition<boolean, boolean> {
-{
 	return define(new BooleanType());
 }
 /**
  * New boolean property definition.
  * Alias of boolean.
  */
-export function bool(): ReturnType<typeof boolean>
+export function bool(): ReturnType<typeof boolean> {
-{
 	return boolean();
 }

src/model/types/date.ts

@@ -5,30 +5,30 @@ import {InvalidTypeValueError} from "../../errors";
 /**
  * Type of dates.
  */
-export class DateType extends Type<string, Date>
+export class DateType extends Type<string, Date> {
-{
+	deserialize(value: string | null | undefined): Date | null | undefined {
-	deserialize(value: string|null|undefined): Date|null|undefined
-	{
 		if (value === undefined) return undefined;
 		if (value === null) return null;
 
 		return new Date(value);
 	}
 
-	serialize(value: Date|null|undefined): string|null|undefined
+	serialize(value: Date | null | undefined): string | null | undefined {
-	{
 		if (value === undefined) return undefined;
 		if (value === null) return null;
-		if (!(value instanceof Date)) throw new InvalidTypeValueError(this, value, "value must be a date");
+		if (!(value instanceof Date))
+			throw new InvalidTypeValueError(this, value, "value must be a date");
 		if (isNaN(value?.valueOf())) return value?.toString();
 
 		return value?.toISOString();
 	}
 
-	hasChanged(originalValue: Date|null|undefined, currentValue: Date|null|undefined): boolean
+	hasChanged(
-	{
+		originalValue: Date | null | undefined,
-		if (originalValue instanceof Date && currentValue instanceof Date)
+		currentValue: Date | null | undefined,
-		{ // Compare dates.
+	): boolean {
+		if (originalValue instanceof Date && currentValue instanceof Date) {
+			// Compare dates.
 			const originalTime = originalValue.getTime();
 			const currentTime = currentValue.getTime();
 
@@ -37,8 +37,7 @@ export class DateType extends Type<string, Date>
 
 			// Timestamps need to be exactly the same.
 			return originalValue.getTime() !== currentValue.getTime();
-		}
+		} else
-		else
 			// Compare undefined or null values.
 			return originalValue !== currentValue;
 	}
@@ -47,7 +46,6 @@ export class DateType extends Type<string, Date>
 /**
  * New date property definition.
  */
-export function date(): Definition<string, Date>
+export function date(): Definition<string, Date> {
-{
 	return define(new DateType());
 }

src/model/types/decimal.ts

@@ -5,21 +5,19 @@ import {InvalidTypeValueError} from "../../errors";
 /**
  * Type of decimal numbers.
  */
-export class DecimalType extends Type<string, number>
+export class DecimalType extends Type<string, number> {
-{
+	deserialize(value: string | null | undefined): number | null | undefined {
-	deserialize(value: string|null|undefined): number|null|undefined
-	{
 		if (value === undefined) return undefined;
 		if (value === null) return null;
 
 		return parseFloat(value);
 	}
 
-	serialize(value: number|null|undefined): string|null|undefined
+	serialize(value: number | null | undefined): string | null | undefined {
-	{
 		if (value === undefined) return undefined;
 		if (value === null) return null;
-		if (typeof value !== "number" && typeof value !== "string") throw new InvalidTypeValueError(this, value, "value must be a number");
+		if (typeof value !== "number" && typeof value !== "string")
+			throw new InvalidTypeValueError(this, value, "value must be a number");
 
 		return value?.toString();
 	}
@@ -28,7 +26,6 @@ export class DecimalType extends Type<string, number>
 /**
  * New decimal property definition.
  */
-export function decimal(): Definition<string, number>
+export function decimal(): Definition<string, number> {
-{
 	return define(new DecimalType());
 }

src/model/types/map.ts

@@ -0,0 +1,264 @@
+import {Type} from "./type";
+import {define, Definition} from "../property-definition";
+import {InvalidTypeValueError} from "../../errors";
+import {string} from "./string";
+
+/**
+ * Type of a key-value map.
+ */
+export class MapType<
+    KeyType,
+    ValueType,
+    SerializedValueType,
+    SerializedMapType extends Record<string, SerializedValueType> = Record<
+        string,
+        SerializedValueType
+    >,
+> extends Type<SerializedMapType, Map<KeyType, ValueType>> {
+    /**
+     * Initialize a new map type of a Sharkitek model property.
+     * @param keyDefinition Definition of the map keys.
+     * @param valueDefinition Definition of the map values.
+     */
+    constructor(
+        protected keyDefinition: Definition<string, KeyType>,
+        protected valueDefinition: Definition<SerializedValueType, ValueType>,
+    ) {
+        super();
+    }
+
+    serialize(
+        value: Map<KeyType, ValueType> | null | undefined,
+    ): SerializedMapType | null | undefined {
+        if (value === undefined) return undefined;
+        if (value === null) return null;
+
+        if (!(value instanceof Map))
+            throw new InvalidTypeValueError(
+                this,
+                value,
+                "value must be an instance of map",
+            );
+
+        return Object.fromEntries(
+            // Serializing each key-value pair of the map.
+            value
+                .entries()
+                .map(([key, value]) => [
+                    this.keyDefinition.type.serialize(key),
+                    this.valueDefinition.type.serialize(value),
+                ]),
+        ) as SerializedMapType;
+    }
+
+    deserialize(
+        value: SerializedMapType | null | undefined,
+    ): Map<KeyType, ValueType> | null | undefined {
+        if (value === undefined) return undefined;
+        if (value === null) return null;
+
+        if (typeof value !== "object" || Array.isArray(value))
+            throw new InvalidTypeValueError(this, value, "value must be an object");
+
+        const map = new Map<KeyType, ValueType>();
+        for (const [serializedKey, serializedValue] of Object.entries(value)) {
+            // Deserializing each key-value pair of the map.
+            map.set(
+                this.keyDefinition.type.deserialize(serializedKey),
+                this.valueDefinition.type.deserialize(serializedValue),
+            );
+        }
+
+        return map;
+    }
+
+    serializeDiff(
+        value: Map<KeyType, ValueType> | null | undefined,
+    ): SerializedMapType | null | undefined {
+        if (value === undefined) return undefined;
+        if (value === null) return null;
+
+        if (!(value instanceof Map))
+            throw new InvalidTypeValueError(
+                this,
+                value,
+                "value must be an instance of map",
+            );
+
+        return Object.fromEntries(
+            // Serializing the diff of each key-value pair of the map.
+            value
+                .entries()
+                .map(([key, value]) => [
+                    this.keyDefinition.type.serializeDiff(key),
+                    this.valueDefinition.type.serializeDiff(value),
+                ]),
+        ) as SerializedMapType;
+    }
+
+    resetDiff(value: Map<KeyType, ValueType> | null | undefined): void {
+        // Do nothing if it is not a map.
+        if (!(value instanceof Map)) return;
+
+        // Reset diff of all key-value pairs.
+        value.forEach((value, key) => {
+            this.keyDefinition.type.resetDiff(key);
+            this.valueDefinition.type.resetDiff(value);
+        });
+    }
+
+    hasChanged(
+        originalValue: Map<KeyType, ValueType> | null | undefined,
+        currentValue: Map<KeyType, ValueType> | null | undefined,
+    ): boolean {
+        // If any map size is different, maps are different.
+        if (originalValue?.size != currentValue?.size) return true;
+        // If size is undefined, values are probably not maps.
+        if (originalValue?.size == undefined)
+            return super.hasChanged(originalValue, currentValue);
+
+        for (const [key, value] of originalValue.entries()) {
+            // Check for any change for each key-value in the map.
+            if (this.valueDefinition.type.hasChanged(value, currentValue.get(key)))
+                // The value has changed, the map is different.
+                return true;
+        }
+
+        return false; // No change detected.
+    }
+
+    serializedHasChanged(
+        originalValue: SerializedMapType | null | undefined,
+        currentValue: SerializedMapType | null | undefined,
+    ): boolean {
+        // If any value is not a defined object, use the default comparison function.
+        if (
+            !originalValue ||
+            !currentValue ||
+            typeof originalValue !== "object" ||
+            typeof currentValue !== "object"
+        )
+            return super.serializedHasChanged(originalValue, currentValue);
+
+        // If any object size is different, objects are different.
+        if (Object.keys(originalValue)?.length != Object.keys(currentValue)?.length)
+            return true;
+
+        for (const [key, value] of Object.entries(originalValue)) {
+            // Check for any change for each key-value pair in the object.
+            if (
+                this.valueDefinition.type.serializedHasChanged(value, currentValue[key])
+            )
+                // The value has changed, the object is different.
+                return true;
+        }
+
+        return false; // No change detected.
+    }
+
+    clone<T extends Map<KeyType, ValueType>>(map: T | null | undefined): T {
+        // Handle NULL / undefined map.
+        if (!map) return super.clone(map);
+
+        if (!(map instanceof Map))
+            throw new InvalidTypeValueError(
+                this,
+                map,
+                "value must be an instance of map",
+            );
+
+        // Initialize an empty map.
+        const cloned = new Map<KeyType, ValueType>() as T;
+
+        for (const [key, value] of map.entries()) {
+            // Clone each value of the map.
+            cloned.set(
+                this.keyDefinition.type.clone(key),
+                this.valueDefinition.type.clone(value),
+            );
+        }
+
+        return cloned; // Returning cloned map.
+    }
+
+    applyPatch<T extends Map<KeyType, ValueType>>(
+        currentValue: T | null | undefined,
+        patchValue: SerializedMapType | null | undefined,
+        updateOriginals: boolean,
+    ): T | null | undefined {
+        if (patchValue === undefined) return undefined;
+        if (patchValue === null) return null;
+
+        if (typeof patchValue !== "object")
+            throw new InvalidTypeValueError(
+                this,
+                patchValue,
+                "value must be an object",
+            );
+
+        currentValue =
+            currentValue instanceof Map
+                ? currentValue
+                : (new Map<KeyType, ValueType>() as T);
+
+        for (const [key, value] of Object.entries(patchValue)) {
+            // Apply the patch to all values of the map.
+            const patchedKey = this.keyDefinition.type.deserialize(key);
+            const patchedElement = this.valueDefinition.type.applyPatch(
+                currentValue.get(patchedKey),
+                value,
+                updateOriginals,
+            );
+            currentValue.set(patchedKey, patchedElement);
+        }
+
+        return currentValue;
+    }
+}
+
+/**
+ * New map property definition.
+ * @param keyDefinition Definition of the map keys.
+ * @param valueDefinition Definition of the map values.
+ */
+export function map<
+    KeyType,
+    ValueType,
+    SerializedValueType,
+    SerializedMapType extends Record<string, SerializedValueType> = Record<
+        string,
+        SerializedValueType
+    >,
+>(
+    keyDefinition: Definition<string, KeyType>,
+    valueDefinition: Definition<SerializedValueType, ValueType>,
+): Definition<SerializedMapType, Map<KeyType, ValueType>> {
+    return define(
+        new MapType<KeyType, ValueType, SerializedValueType, SerializedMapType>(
+            keyDefinition,
+            valueDefinition,
+        ),
+    );
+}
+
+/**
+ * New map property definition, with string as index.
+ * @param valueDefinition Definition of the map values.
+ */
+export function stringMap<
+    ValueType,
+    SerializedValueType,
+    SerializedMapType extends Record<string, SerializedValueType> = Record<
+        string,
+        SerializedValueType
+    >,
+>(
+    valueDefinition: Definition<SerializedValueType, ValueType>,
+): Definition<SerializedMapType, Map<string, ValueType>> {
+    return define(
+        new MapType<string, ValueType, SerializedValueType, SerializedMapType>(
+            string(),
+            valueDefinition,
+        ),
+    );
+}

src/model/types/model.ts

@@ -2,50 +2,62 @@ import {Type} from "./type";
 import {define, Definition} from "../property-definition";
 import {
 	GenericModelManager,
-	IdentifierDefinition, DeclaredModelManager,
+	IdentifierDefinition,
+	DeclaredModelManager,
 	ModelInstance,
 	ModelManager,
 	ModelShape,
-	SerializedModel
+	SerializedModel,
 } from "../model";
 import {InvalidTypeValueError} from "../../errors";
 
 /**
  * Type of a Sharkitek model value.
  */
-export class ModelType<T extends object, Shape extends ModelShape<T>, Identifier extends IdentifierDefinition<T, Shape>> extends Type<SerializedModel<T, Shape>, ModelInstance<T, Shape, Identifier>>
+export class ModelType<
-{
+	T extends object,
+	Shape extends ModelShape<T>,
+	Identifier extends IdentifierDefinition<T, Shape>,
+> extends Type<SerializedModel<T, Shape>, ModelInstance<T, Shape, Identifier>> {
 	/**
 	 * Initialize a new model type of a Sharkitek model property.
 	 * @param declaredModelManager Model manager.
 	 */
-	constructor(protected declaredModelManager: DeclaredModelManager<T, Shape, Identifier>)
+	constructor(
-	{
+		protected declaredModelManager: DeclaredModelManager<T, Shape, Identifier>,
+	) {
 		super();
 	}
 
 	/**
 	 * Resolve the defined model using the declared model, that can be defined lazily.
 	 */
-	get definedModel(): ModelManager<T, Shape, Identifier>
+	get definedModel(): ModelManager<T, Shape, Identifier> {
-	{
+		return typeof this.declaredModelManager == "object"
-		return typeof this.declaredModelManager == "object" ? this.declaredModelManager : this.declaredModelManager();
+			? this.declaredModelManager
+			: this.declaredModelManager();
 	}
 
-	serialize(value: ModelInstance<T, Shape, Identifier>|null|undefined): SerializedModel<T, Shape>|null|undefined
+	serialize(
-	{
+		value: ModelInstance<T, Shape, Identifier> | null | undefined,
+	): SerializedModel<T, Shape> | null | undefined {
 		if (value === undefined) return undefined;
 		if (value === null) return null;
 
 		if (!(value instanceof this.definedModel.definition.Class))
-			throw new InvalidTypeValueError(this, value, `value must be a compatible model (given ${value.constructor.name}, expected ${this.definedModel.definition.Class.name})`);
+			throw new InvalidTypeValueError(
+				this,
+				value,
+				`value must be a compatible model (given ${value.constructor.name}, expected ${this.definedModel.definition.Class.name})`,
+			);
 
 		// Serializing the given model.
 		return this.definedModel.model(value).serialize();
 	}
 
-	deserialize(value: SerializedModel<T, Shape>|null|undefined): ModelInstance<T, Shape, Identifier>|null|undefined
+	deserialize(
-	{
+		value: SerializedModel<T, Shape> | null | undefined,
+	): ModelInstance<T, Shape, Identifier> | null | undefined {
 		if (value === undefined) return undefined;
 		if (value === null) return null;
 
@@ -56,90 +68,158 @@ export class ModelType<T extends object, Shape extends ModelShape<T>, Identifier
 		return this.definedModel.parse(value);
 	}
 
-	serializeDiff(value: ModelInstance<T, Shape, Identifier>|null|undefined): Partial<SerializedModel<T, Shape>>|null|undefined
+	serializeDiff(
-	{
+		value: ModelInstance<T, Shape, Identifier> | null | undefined,
+	): Partial<SerializedModel<T, Shape>> | null | undefined {
 		if (value === undefined) return undefined;
 		if (value === null) return null;
 
 		if (!(value instanceof this.definedModel.definition.Class))
-			throw new InvalidTypeValueError(this, value, `value must be a compatible model (given ${value.constructor.name}, expected ${this.definedModel.definition.Class.name})`);
+			throw new InvalidTypeValueError(
+				this,
+				value,
+				`value must be a compatible model (given ${value.constructor.name}, expected ${this.definedModel.definition.Class.name})`,
+			);
 
 		// Serializing the given model.
 		return this.definedModel.model(value).serializeDiff();
 	}
 
-	resetDiff(value: ModelInstance<T, Shape, Identifier>|null|undefined): void
+	resetDiff(
-	{
+		value: ModelInstance<T, Shape, Identifier> | null | undefined,
+	): void {
 		if (value === undefined) return;
 		if (value === null) return;
 
 		if (!(value instanceof this.definedModel.definition.Class))
-			throw new InvalidTypeValueError(this, value, `value must be a compatible model (given ${value.constructor.name}, expected ${this.definedModel.definition.Class.name})`);
+			throw new InvalidTypeValueError(
+				this,
+				value,
+				`value must be a compatible model (given ${value.constructor.name}, expected ${this.definedModel.definition.Class.name})`,
+			);
 
 		// Reset diff of the given model.
 		this.definedModel.model(value).resetDiff();
 	}
 
-	hasChanged(originalValue: ModelInstance<T, Shape, Identifier>|null|undefined, currentValue: ModelInstance<T, Shape, Identifier>|null|undefined): boolean
+	hasChanged(
-	{
+		originalValue: ModelInstance<T, Shape, Identifier> | null | undefined,
+		currentValue: ModelInstance<T, Shape, Identifier> | null | undefined,
+	): boolean {
 		if (originalValue === undefined) return currentValue !== undefined;
 		if (originalValue === null) return currentValue !== null;
 		if (currentValue === undefined) return true; // Original value is not undefined.
 		if (currentValue === null) return true; // Original value is not null.
 
 		if (!(originalValue instanceof this.definedModel.definition.Class))
-			throw new InvalidTypeValueError(this, originalValue, `value must be a compatible model (given ${originalValue.constructor.name}, expected ${this.definedModel.definition.Class.name})`);
+			throw new InvalidTypeValueError(
+				this,
+				originalValue,
+				`value must be a compatible model (given ${originalValue.constructor.name}, expected ${this.definedModel.definition.Class.name})`,
+			);
 		if (!(currentValue instanceof this.definedModel.definition.Class))
-			throw new InvalidTypeValueError(this, currentValue, `value must be a compatible model (given ${currentValue.constructor.name}, expected ${this.definedModel.definition.Class.name})`);
+			throw new InvalidTypeValueError(
+				this,
+				currentValue,
+				`value must be a compatible model (given ${currentValue.constructor.name}, expected ${this.definedModel.definition.Class.name})`,
+			);
 
 		// If the current value is dirty, it has changed.
 		return this.definedModel.model(currentValue).isDirty();
 	}
 
-	serializedHasChanged(originalValue: SerializedModel<T, Shape> | null | undefined, currentValue: SerializedModel<T, Shape> | null | undefined): boolean
+	serializedHasChanged(
-	{
+		originalValue: SerializedModel<T, Shape> | null | undefined,
+		currentValue: SerializedModel<T, Shape> | null | undefined,
+	): boolean {
 		if (originalValue === undefined) return currentValue !== undefined;
 		if (originalValue === null) return currentValue !== null;
 		if (currentValue === undefined) return true; // Original value is not undefined.
 		if (currentValue === null) return true; // Original value is not null.
 
 		if (typeof originalValue !== "object" || Array.isArray(originalValue))
-			throw new InvalidTypeValueError(this, originalValue, "value must be an object");
+			throw new InvalidTypeValueError(
+				this,
+				originalValue,
+				"value must be an object",
+			);
 		if (typeof currentValue !== "object" || Array.isArray(currentValue))
-			throw new InvalidTypeValueError(this, currentValue, "value must be an object");
+			throw new InvalidTypeValueError(
+				this,
+				currentValue,
+				"value must be an object",
+			);
 
 		// If any property has changed, the value has changed.
 		for (const property of this.definedModel.properties)
-			if (property.definition.type.serializedHasChanged(originalValue?.[property.name], currentValue?.[property.name]))
+			if (
+				property.definition.type.serializedHasChanged(
+					originalValue?.[property.name],
+					currentValue?.[property.name],
+				)
+			)
 				return true;
 
 		return false; // No change detected.
 	}
 
-	clone<Type extends ModelInstance<T, Shape, Identifier>>(value: Type|null|undefined): Type
+	clone<Type extends ModelInstance<T, Shape, Identifier>>(
-	{
+		value: Type | null | undefined,
+	): Type {
 		// Handle NULL / undefined values.
 		if (!value) return super.clone(value);
 
 		if (!(value instanceof this.definedModel.definition.Class))
-			throw new InvalidTypeValueError(this, value, `value must be a compatible model (given ${value.constructor.name}, expected ${this.definedModel.definition.Class.name})`);
+			throw new InvalidTypeValueError(
+				this,
+				value,
+				`value must be a compatible model (given ${value.constructor.name}, expected ${this.definedModel.definition.Class.name})`,
+			);
 
 		return this.definedModel.model(value).clone() as Type;
 	}
+
+	applyPatch<Type extends ModelInstance<T, Shape, Identifier>>(
+		currentValue: Type | null | undefined,
+		patchValue: SerializedModel<T, Shape> | null | undefined,
+		updateOriginals: boolean,
+	): Type | null | undefined {
+		if (patchValue === undefined) return undefined;
+		if (patchValue === null) return null;
+
+		if (typeof patchValue !== "object" || Array.isArray(patchValue))
+			throw new InvalidTypeValueError(
+				this,
+				patchValue,
+				"value must be an object",
+			);
+
+		return this.definedModel
+			.model(currentValue)
+			.applyPatch(patchValue, updateOriginals) as Type;
+	}
 }
 
 /**
  * New model property definition.
  * @param definedModel Model manager.
  */
-export function model<T extends object, Shape extends ModelShape<T>, Identifier extends IdentifierDefinition<T, Shape>>(
+export function model<
-	definedModel: DeclaredModelManager<T, Shape, Identifier>
+	T extends object,
-): Definition<SerializedModel<T, Shape>, ModelInstance<T, Shape, Identifier>>
+	Shape extends ModelShape<T>,
-{
+	Identifier extends IdentifierDefinition<T, Shape>,
+>(
+	definedModel: DeclaredModelManager<T, Shape, Identifier>,
+): Definition<SerializedModel<T, Shape>, ModelInstance<T, Shape, Identifier>> {
 	return define(new ModelType(definedModel));
 }
 
-export function circular<T extends object>(definedModel: () => any): () => GenericModelManager<T>
+/**
-{
+ * Utility function to fix circular dependencies issues.
+ * @param definedModel A function returning the model to use.
+ */
+export function circular<T extends object>(
+	definedModel: () => any,
+): () => GenericModelManager<T> {
 	return definedModel;
 }

src/model/types/numeric.ts

@@ -5,24 +5,23 @@ import {InvalidTypeValueError} from "../../errors";
 /**
  * Type of any numeric value.
  */
-export class NumericType extends Type<number, number>
+export class NumericType extends Type<number, number> {
-{
+	deserialize(value: number | null | undefined): number | null | undefined {
-	deserialize(value: number|null|undefined): number|null|undefined
-	{
 		if (value === undefined) return undefined;
 		if (value === null) return null;
 
-		if (typeof value !== "number") throw new InvalidTypeValueError(this, value, "value must be a number");
+		if (typeof value !== "number")
+			throw new InvalidTypeValueError(this, value, "value must be a number");
 
 		return value;
 	}
 
-	serialize(value: number|null|undefined): number|null|undefined
+	serialize(value: number | null | undefined): number | null | undefined {
-	{
 		if (value === undefined) return undefined;
 		if (value === null) return null;
 
-		if (typeof value !== "number") throw new InvalidTypeValueError(this, value, "value must be a number");
+		if (typeof value !== "number")
+			throw new InvalidTypeValueError(this, value, "value must be a number");
 
 		return value;
 	}
@@ -31,7 +30,6 @@ export class NumericType extends Type<number, number>
 /**
  * New numeric property definition.
  */
-export function numeric(): Definition<number, number>
+export function numeric(): Definition<number, number> {
-{
 	return define(new NumericType());
 }

src/model/types/object.ts

@@ -1,13 +1,21 @@
 import {Type} from "./type";
-import {define, Definition} from "../property-definition";
+import {define, Definition, UnknownDefinition} from "../property-definition";
-import {ModelProperties, ModelPropertiesValues, ModelProperty, ModelShape, SerializedModel} from "../model";
+import {
+	ModelProperties,
+	ModelPropertiesValues,
+	ModelProperty,
+	ModelShape,
+	SerializedModel,
+} from "../model";
 import {InvalidTypeValueError} from "../../errors";
 
 /**
  * Type of a custom object.
  */
-export class ObjectType<Shape extends ModelShape<T>, T extends object> extends Type<SerializedModel<T, Shape>, ModelPropertiesValues<T, Shape>>
+export class ObjectType<
-{
+	Shape extends ModelShape<T>,
+	T extends object,
+> extends Type<SerializedModel<T, Shape>, ModelPropertiesValues<T, Shape>> {
 	/**
 	 * Defined properties.
 	 */
@@ -17,8 +25,7 @@ export class ObjectType<Shape extends ModelShape<T>, T extends object> extends T
 	 * Initialize a new object type of a Sharkitek model property.
 	 * @param shape
 	 */
-	constructor(readonly shape: Shape)
+	constructor(readonly shape: Shape) {
-	{
 		super();
 		this.initProperties();
 	}
@@ -27,12 +34,11 @@ export class ObjectType<Shape extends ModelShape<T>, T extends object> extends T
 	 * Initialize properties iterator from the object shape.
 	 * @protected
 	 */
-	protected initProperties(): void
+	protected initProperties(): void {
-	{
 		// Build an array of model properties from the object shape.
 		this.properties = [];
-		for (const propertyName in this.shape)
+		for (const propertyName in this.shape) {
-		{ // For each property, build a model property object.
+			// For each property, build a model property object.
 			this.properties.push({
 				name: propertyName,
 				definition: this.shape[propertyName],
@@ -41,8 +47,9 @@ export class ObjectType<Shape extends ModelShape<T>, T extends object> extends T
 		}
 	}
 
-	deserialize(value: SerializedModel<T, Shape>|null|undefined): ModelPropertiesValues<T, Shape>|null|undefined
+	deserialize(
-	{
+		value: SerializedModel<T, Shape> | null | undefined,
+	): ModelPropertiesValues<T, Shape> | null | undefined {
 		if (value === undefined) return undefined;
 		if (value === null) return null;
 
@@ -52,16 +59,18 @@ export class ObjectType<Shape extends ModelShape<T>, T extends object> extends T
 		// Initialize an empty object.
 		const obj: Partial<ModelPropertiesValues<T, Shape>> = {};
 
-		for (const property of this.properties)
+		for (const property of this.properties) {
-		{ // For each defined property, deserialize its value according to its type.
+			// For each defined property, deserialize its value according to its type.
-			(obj[property.name as keyof T] as any) = property.definition.type.deserialize(value?.[property.name]);
+			(obj[property.name as keyof T] as any) =
+				property.definition.type.deserialize(value?.[property.name]);
 		}
 
 		return obj as ModelPropertiesValues<T, Shape>; // Returning serialized object.
 	}
 
-	serialize(value: ModelPropertiesValues<T, Shape>|null|undefined): SerializedModel<T, Shape>|null|undefined
+	serialize(
-	{
+		value: ModelPropertiesValues<T, Shape> | null | undefined,
+	): SerializedModel<T, Shape> | null | undefined {
 		if (value === undefined) return undefined;
 		if (value === null) return null;
 
@@ -71,8 +80,8 @@ export class ObjectType<Shape extends ModelShape<T>, T extends object> extends T
 		// Creating an empty serialized object.
 		const serializedObject: Partial<SerializedModel<T, Shape>> = {};
 
-		for (const property of this.properties)
+		for (const property of this.properties) {
-		{ // For each property, adding it to the serialized object.
+			// For each property, adding it to the serialized object.
 			serializedObject[property.name] = property.definition.type.serialize(
 				// keyof Shape is a subset of keyof T.
 				value?.[property.name as keyof T],
@@ -82,8 +91,9 @@ export class ObjectType<Shape extends ModelShape<T>, T extends object> extends T
 		return serializedObject as SerializedModel<T, Shape>; // Returning the serialized object.
 	}
 
-	serializeDiff(value: ModelPropertiesValues<T, Shape>|null|undefined): Partial<SerializedModel<T, Shape>>|null|undefined
+	serializeDiff(
-	{
+		value: ModelPropertiesValues<T, Shape> | null | undefined,
+	): Partial<SerializedModel<T, Shape>> | null | undefined {
 		if (value === undefined) return undefined;
 		if (value === null) return null;
 
@@ -93,8 +103,8 @@ export class ObjectType<Shape extends ModelShape<T>, T extends object> extends T
 		// Creating an empty serialized object.
 		const serializedObject: Partial<SerializedModel<T, Shape>> = {};
 
-		for (const property of this.properties)
+		for (const property of this.properties) {
-		{ // For each property, adding it to the serialized object.
+			// For each property, adding it to the serialized object.
 			serializedObject[property.name] = property.definition.type.serializeDiff(
 				// keyof Shape is a subset of keyof T.
 				value?.[property.name as keyof T],
@@ -104,8 +114,7 @@ export class ObjectType<Shape extends ModelShape<T>, T extends object> extends T
 		return serializedObject as SerializedModel<T, Shape>; // Returning the serialized object.
 	}
 
-	resetDiff(value: ModelPropertiesValues<T, Shape>|null|undefined)
+	resetDiff(value: ModelPropertiesValues<T, Shape> | null | undefined) {
-	{
 		if (value === undefined) return;
 		if (value === null) return;
 
@@ -113,53 +122,84 @@ export class ObjectType<Shape extends ModelShape<T>, T extends object> extends T
 			throw new InvalidTypeValueError(this, value, "value must be an object");
 
 		// For each property, reset its diff.
-		for (const property of this.properties)
 		// keyof Shape is a subset of keyof T.
+		for (const property of this.properties)
 			property.definition.type.resetDiff(value?.[property.name as keyof T]);
 	}
 
-	hasChanged(originalValue: ModelPropertiesValues<T, Shape>|null|undefined, currentValue: ModelPropertiesValues<T, Shape>|null|undefined): boolean
+	hasChanged(
-	{
+		originalValue: ModelPropertiesValues<T, Shape> | null | undefined,
+		currentValue: ModelPropertiesValues<T, Shape> | null | undefined,
+	): boolean {
 		if (originalValue === undefined) return currentValue !== undefined;
 		if (originalValue === null) return currentValue !== null;
 		if (currentValue === undefined) return true; // Original value is not undefined.
 		if (currentValue === null) return true; // Original value is not null.
 
 		if (typeof originalValue !== "object" || Array.isArray(originalValue))
-			throw new InvalidTypeValueError(this, originalValue, "value must be an object");
+			throw new InvalidTypeValueError(
+				this,
+				originalValue,
+				"value must be an object",
+			);
 		if (typeof currentValue !== "object" || Array.isArray(currentValue))
-			throw new InvalidTypeValueError(this, currentValue, "value must be an object");
+			throw new InvalidTypeValueError(
+				this,
+				currentValue,
+				"value must be an object",
+			);
 
 		// If any property has changed, the value has changed.
 		for (const property of this.properties)
-			if (property.definition.type.hasChanged(originalValue?.[property.name as keyof T], currentValue?.[property.name as keyof T]))
+			if (
+				property.definition.type.hasChanged(
+					originalValue?.[property.name as keyof T],
+					currentValue?.[property.name as keyof T],
+				)
+			)
 				return true;
 
 		return false; // No change detected.
 	}
 
-	serializedHasChanged(originalValue: SerializedModel<T, Shape>|null|undefined, currentValue: SerializedModel<T, Shape>|null|undefined): boolean
+	serializedHasChanged(
-	{
+		originalValue: SerializedModel<T, Shape> | null | undefined,
+		currentValue: SerializedModel<T, Shape> | null | undefined,
+	): boolean {
 		if (originalValue === undefined) return currentValue !== undefined;
 		if (originalValue === null) return currentValue !== null;
 		if (currentValue === undefined) return true; // Original value is not undefined.
 		if (currentValue === null) return true; // Original value is not null.
 
 		if (typeof originalValue !== "object" || Array.isArray(originalValue))
-			throw new InvalidTypeValueError(this, originalValue, "value must be an object");
+			throw new InvalidTypeValueError(
+				this,
+				originalValue,
+				"value must be an object",
+			);
 		if (typeof currentValue !== "object" || Array.isArray(currentValue))
-			throw new InvalidTypeValueError(this, currentValue, "value must be an object");
+			throw new InvalidTypeValueError(
+				this,
+				currentValue,
+				"value must be an object",
+			);
 
 		// If any property has changed, the value has changed.
 		for (const property of this.properties)
-			if (property.definition.type.serializedHasChanged(originalValue?.[property.name], currentValue?.[property.name]))
+			if (
+				property.definition.type.serializedHasChanged(
+					originalValue?.[property.name],
+					currentValue?.[property.name],
+				)
+			)
 				return true;
 
 		return false; // No change detected.
 	}
 
-	clone<Type extends ModelPropertiesValues<T, Shape>>(value: Type|null|undefined): Type
+	clone<Type extends ModelPropertiesValues<T, Shape>>(
-	{
+		value: Type | null | undefined,
+	): Type {
 		// Handle NULL / undefined object.
 		if (!value) return super.clone(value);
 
@@ -169,20 +209,59 @@ export class ObjectType<Shape extends ModelShape<T>, T extends object> extends T
 		// Initialize an empty object.
 		const cloned: Partial<ModelPropertiesValues<T, Shape>> = {};
 
-		for (const property of this.properties)
+		for (const property of this.properties) {
-		{ // For each defined property, clone it.
+			// For each defined property, clone it.
-			cloned[property.name as keyof T] = property.definition.type.clone(value?.[property.name]);
+			cloned[property.name as keyof T] = property.definition.type.clone(
+				value?.[property.name],
+			);
 		}
 
 		return cloned as Type; // Returning cloned object.
 	}
+
+	applyPatch<Type extends ModelPropertiesValues<T, Shape>>(
+		currentValue: Type | null | undefined,
+		patchValue: SerializedModel<T, Shape> | null | undefined,
+		updateOriginals: boolean,
+	): Type | null | undefined {
+		if (patchValue === undefined) return undefined;
+		if (patchValue === null) return null;
+
+		if (typeof patchValue !== "object" || Array.isArray(patchValue))
+			throw new InvalidTypeValueError(
+				this,
+				patchValue,
+				"value must be an object",
+			);
+
+		const patchedValue: Partial<Type> =
+			typeof currentValue === "object" && currentValue !== null
+				? currentValue
+				: {};
+
+		for (const key in patchValue) {
+			// Apply the patch to each property of the patch value.
+			const propertyDef = this.shape[key];
+			if (propertyDef)
+				patchedValue[key as keyof Type] = (
+					propertyDef as UnknownDefinition
+				).type.applyPatch(
+					currentValue?.[key as keyof Type],
+					patchValue[key],
+					updateOriginals,
+				);
+		}
+
+		return patchedValue as Type;
+	}
 }
 
 /**
  * New object property definition.
  * @param shape Shape of the object.
  */
-export function object<Shape extends ModelShape<T>, T extends object>(shape: Shape): Definition<SerializedModel<T, Shape>, ModelPropertiesValues<T, Shape>>
+export function object<Shape extends ModelShape<T>, T extends object>(
-{
+	shape: Shape,
+): Definition<SerializedModel<T, Shape>, ModelPropertiesValues<T, Shape>> {
 	return define(new ObjectType(shape));
 }

src/model/types/string.ts

@@ -4,18 +4,15 @@ import {define, Definition} from "../property-definition";
 /**
  * Type of any string value.
  */
-export class StringType extends Type<string, string>
+export class StringType extends Type<string, string> {
-{
+	deserialize(value: string | null | undefined): string | null | undefined {
-	deserialize(value: string|null|undefined): string|null|undefined
-	{
 		if (value === undefined) return undefined;
 		if (value === null) return null;
 
 		return String(value);
 	}
 
-	serialize(value: string|null|undefined): string|null|undefined
+	serialize(value: string | null | undefined): string | null | undefined {
-	{
 		if (value === undefined) return undefined;
 		if (value === null) return null;
 
@@ -26,7 +23,6 @@ export class StringType extends Type<string, string>
 /**
  * New string property definition.
  */
-export function string(): Definition<string, string>
+export function string(): Definition<string, string> {
-{
 	return define(new StringType());
 }

src/model/types/type.ts

@@ -1,26 +1,30 @@
 /**
  * Abstract class of a Sharkitek model property type.
  */
-export abstract class Type<SerializedType, ModelType>
+export abstract class Type<SerializedType, ModelType> {
-{
 	/**
 	 * Serialize the given value of a Sharkitek model property.
 	 * @param value Value to serialize.
 	 */
-	abstract serialize(value: ModelType|null|undefined): SerializedType|null|undefined;
+	abstract serialize(
+		value: ModelType | null | undefined,
+	): SerializedType | null | undefined;
 
 	/**
 	 * Deserialize the given value of a serialized Sharkitek model.
 	 * @param value Value to deserialize.
 	 */
-	abstract deserialize(value: SerializedType|null|undefined): ModelType|null|undefined;
+	abstract deserialize(
+		value: SerializedType | null | undefined,
+	): ModelType | null | undefined;
 
 	/**
 	 * Serialize the given value only if it has changed.
 	 * @param value Value to deserialize.
 	 */
-	serializeDiff(value: ModelType|null|undefined): Partial<SerializedType>|null|undefined
+	serializeDiff(
-	{
+		value: ModelType | null | undefined,
+	): Partial<SerializedType> | null | undefined {
 		return this.serialize(value); // By default, nothing changes.
 	}
 
@@ -28,8 +32,10 @@ export abstract class Type<SerializedType, ModelType>
 	 * Reset the difference between the original value and the current one.
 	 * @param value Value for which reset diff data.
 	 */
-	resetDiff(value: ModelType|null|undefined): void
+	resetDiff(
-	{
+		// eslint-disable-next-line @typescript-eslint/no-unused-vars
+		value: ModelType | null | undefined,
+	): void {
 		// By default, nothing to do.
 	}
 
@@ -38,8 +44,10 @@ export abstract class Type<SerializedType, ModelType>
 	 * @param originalValue Original value.
 	 * @param currentValue Current value.
 	 */
-	hasChanged(originalValue: ModelType|null|undefined, currentValue: ModelType|null|undefined): boolean
+	hasChanged(
-	{
+		originalValue: ModelType | null | undefined,
+		currentValue: ModelType | null | undefined,
+	): boolean {
 		return originalValue !== currentValue;
 	}
 
@@ -48,8 +56,10 @@ export abstract class Type<SerializedType, ModelType>
 	 * @param originalValue Original serialized value.
 	 * @param currentValue Current serialized value.
 	 */
-	serializedHasChanged(originalValue: SerializedType|null|undefined, currentValue: SerializedType|null|undefined): boolean
+	serializedHasChanged(
-	{
+		originalValue: SerializedType | null | undefined,
+		currentValue: SerializedType | null | undefined,
+	): boolean {
 		return originalValue !== currentValue;
 	}
 
@@ -57,8 +67,22 @@ export abstract class Type<SerializedType, ModelType>
 	 * Clone the provided value.
 	 * @param value The to clone.
 	 */
-	clone<T extends ModelType>(value: T|null|undefined): T
+	clone<T extends ModelType>(value: T | null | undefined): T {
-	{
 		return structuredClone(value);
 	}
+
+	/**
+	 * Apply the patch value.
+	 * @param currentValue The current property value. Its value can be mutated directly.
+	 * @param patchValue The serialized patch value.
+	 * @param updateOriginals Indicates if the original properties values must be updated or not.
+	 */
+	applyPatch<T extends ModelType>(
+		currentValue: T | null | undefined,
+		patchValue: SerializedType | null | undefined,
+		// eslint-disable-next-line @typescript-eslint/no-unused-vars
+		updateOriginals: boolean,
+	): T | null | undefined {
+		return this.deserialize(patchValue) as T;
+	}
 }

src/utils.ts

@@ -1,4 +1,10 @@
 /**
  * Type definition of a class constructor.
  */
-export type ConstructorOf<T extends object> = { new(): T; };
+export type ConstructorOf<T extends object> = {new (): T};
+
+/**
+ * Type definition of an original object overridden by another.
+ */
+export type Modify<Original, Override> = Omit<Original, keyof Override> &
+	Override;

tests/builder.test.ts

@@ -0,0 +1,35 @@
+import {describe, expect, test} from "vitest";
+
+import {defineModel, newModel, s} from "../src/library";
+
+class Testest {
+	foo: string;
+	bar: number;
+	baz: boolean;
+}
+
+describe("model builder", () => {
+	const modelBuilder = newModel(Testest)
+		.property("foo", s.property.string())
+		.property("bar", s.property.decimal())
+		.property("baz", s.property.boolean())
+		.identifier("foo");
+
+	test("build model definition", () => {
+		expect(modelBuilder.definition).toStrictEqual({
+			Class: Testest,
+			identifier: "foo",
+			properties: {
+				foo: s.property.string(),
+				bar: s.property.decimal(),
+				baz: s.property.boolean(),
+			},
+		});
+	});
+
+	test("build a model", () => {
+		expect(modelBuilder.define()).toStrictEqual(
+			defineModel(modelBuilder.definition),
+		);
+	});
+});

tests/errors.test.ts

@@ -4,12 +4,21 @@ import {s} from "../src/library";
 
 describe("errors", () => {
 	it("tests type error", () => {
-		expect((new TypeError(s.property.string().type)).message).toBe("Error in type StringType");
+		expect(new TypeError(s.property.string().type).message).toBe(
-		expect((new TypeError(s.property.string().type, "test")).message).toBe("Error in type StringType: test");
+			"Error in type StringType",
+		);
+		expect(new TypeError(s.property.string().type, "test").message).toBe(
+			"Error in type StringType: test",
+		);
 	});
 
 	it("tests invalid type value error", () => {
-		expect((new InvalidTypeValueError(s.property.decimal().type, ["value"])).message).toBe("Error in type DecimalType: [\"value\"] is an invalid value");
+		expect(
-		expect((new InvalidTypeValueError(s.property.decimal().type, ["value"], "test")).message).toBe("Error in type DecimalType: test");
+			new InvalidTypeValueError(s.property.decimal().type, ["value"]).message,
+		).toBe('Error in type DecimalType: ["value"] is an invalid value');
+		expect(
+			new InvalidTypeValueError(s.property.decimal().type, ["value"], "test")
+				.message,
+		).toBe("Error in type DecimalType: test");
 	});
 });

tests/model.test.ts

@@ -4,9 +4,15 @@ import {circular, defineModel, s} from "../src/library";
 /**
  * Test class of an account.
  */
-class Account
+class Account {
-{
+	id: number;
-	static model = s.defineModel({
+	createdAt: Date;
+	name: string;
+	email: string;
+	active: boolean;
+}
+
+const AccountModel = s.defineModel({
 	Class: Account,
 	identifier: "id",
 	properties: {
@@ -16,70 +22,60 @@ class Account
 		email: s.property.string(),
 		active: s.property.boolean(),
 	},
-	});
+});
-
-	id: number;
-	createdAt: Date;
-	name: string;
-	email: string;
-	active: boolean;
-}
 
 /**
  * Test class of an article.
  */
-class Article
+class Article {
-{
-	static model = s.defineModel({
-		Class: Article,
-		identifier: "id",
-		properties: {
-			id: s.property.numeric(),
-			title: s.property.string(),
-			authors: s.property.array(s.property.model(() => Account.model)),
-			text: s.property.string(),
-			evaluation: s.property.decimal(),
-			tags: s.property.array(s.property.object({ name: s.property.string() })),
-			comments: s.property.array(s.property.model(() => ArticleComment.model)),
-		},
-	});
-
 	id: number;
 	title: string;
 	authors: Account[];
 	text: string;
 	evaluation: number;
-	tags: { name: string }[];
+	tags: {name: string}[];
 	comments: ArticleComment[];
 }
 
+const ArticleModel = s.defineModel({
+	Class: Article,
+	identifier: "id",
+	properties: {
+		id: s.property.numeric(),
+		title: s.property.string(),
+		authors: s.property.array(s.property.model(() => AccountModel)),
+		text: s.property.string(),
+		evaluation: s.property.decimal(),
+		tags: s.property.array(s.property.object({name: s.property.string()})),
+		comments: s.property.array(s.property.model(() => ArticleCommentModel)),
+	},
+});
+
 /**
  * Test class of a comment on an article.
  */
-class ArticleComment
+class ArticleComment {
-{
-	static model = s.defineModel({
-		Class: ArticleComment,
-		identifier: "id",
-		properties: {
-			id: s.property.numeric(),
-			article: s.property.model(circular<Article>(() => Article.model)),
-			author: s.property.model(() => Account.model),
-			message: s.property.string(),
-		},
-	});
-
 	id: number;
 	article?: Article;
 	author: Account;
 	message: string;
 }
 
+const ArticleCommentModel = s.defineModel({
+	Class: ArticleComment,
+	identifier: "id",
+	properties: {
+		id: s.property.numeric(),
+		article: s.property.model(circular<Article>(() => ArticleModel)),
+		author: s.property.model(() => AccountModel),
+		message: s.property.string(),
+	},
+});
+
 /**
  * Get a test account instance.
  */
-function getTestAccount(): Account
+function getTestAccount(): Account {
-{
 	const account = new Account();
 	account.id = 52;
 	account.createdAt = new Date();
@@ -89,40 +85,60 @@ function getTestAccount(): Account
 	return account;
 }
 
-function getTestArticle(): Article
+function getTestArticle(): Article {
-{
 	const article = new Article();
 	article.id = 1;
 	article.title = "this is a test";
 	article.text = "this is a long test.";
 	article.evaluation = 25.23;
-	article.tags = [
+	article.tags = [{name: "test"}, {name: "foo"}];
-		{ name: "test" },
-		{ name: "foo" },
-	];
 	article.authors = [getTestAccount()];
 	article.comments = [];
 	return article;
 }
 
 describe("model", () => {
+	it("defines a new model, extending an existing one", () => {
+		class ExtendedAccount extends Account {
+			extendedProperty: string;
+		}
+
+		const ExtendedAccountModel = s.extend(AccountModel, {
+			Class: ExtendedAccount,
+			properties: {
+				extendedProperty: s.property.string(),
+			},
+		});
+
+		expect(ExtendedAccountModel.definition).toEqual({
+			Class: ExtendedAccount,
+			identifier: "id",
+			properties: {
+				id: s.property.numeric(),
+				createdAt: s.property.date(),
+				name: s.property.string(),
+				email: s.property.string(),
+				active: s.property.boolean(),
+				extendedProperty: s.property.string(),
+			},
+		});
+	});
 	it("initializes a new model", () => {
 		const article = getTestArticle();
-		const newModel = Article.model.model(article);
+		const newModel = ArticleModel.model(article);
 		expect(newModel.instance).toBe(article);
 	});
 	it("gets a model state from its instance", () => {
 		const article = getTestArticle();
-		expect(Article.model.model(article).isNew()).toBeTruthy();
+		expect(ArticleModel.model(article).isNew()).toBeTruthy();
-		expect(Article.model.model(article).isDirty()).toBeFalsy();
+		expect(ArticleModel.model(article).isDirty()).toBeFalsy();
 	});
 	it("gets a model identifier value", () => {
 		const article = getTestArticle();
-		expect(Article.model.model(article).getIdentifier()).toBe(1);
+		expect(ArticleModel.model(article).getIdentifier()).toBe(1);
 	});
 	it("gets a model composite identifier value", () => {
-		class CompositeModel
+		class CompositeModel {
-		{
 			static model = s.defineModel({
 				Class: CompositeModel,
 				properties: {
@@ -131,7 +147,7 @@ describe("model", () => {
 					label: s.property.string(),
 				},
 				identifier: ["firstId", "secondId"],
-			})
+			});
 
 			firstId: number;
 			secondId: number;
@@ -139,20 +155,24 @@ describe("model", () => {
 		}
 
 		expect(
-			CompositeModel.model.model(Object.assign(new CompositeModel(), {
+			CompositeModel.model
+				.model(
+					Object.assign(new CompositeModel(), {
 						firstId: 5,
 						secondId: 6,
 						label: "test",
-			})).getIdentifier()
+					}),
+				)
+				.getIdentifier(),
 		).toStrictEqual([5, 6]);
 	});
 	it("checks model dirtiness when altered, then reset diff", () => {
 		const article = getTestArticle();
-		expect(Article.model.model(article).isDirty()).toBeFalsy();
+		expect(ArticleModel.model(article).isDirty()).toBeFalsy();
 		article.title = "new title";
-		expect(Article.model.model(article).isDirty()).toBeTruthy();
+		expect(ArticleModel.model(article).isDirty()).toBeTruthy();
-		Article.model.model(article).resetDiff()
+		ArticleModel.model(article).resetDiff();
-		expect(Article.model.model(article).isDirty()).toBeFalsy();
+		expect(ArticleModel.model(article).isDirty()).toBeFalsy();
 	});
 
 	it("deserializes a model from a serialized form", () => {
@@ -160,38 +180,84 @@ describe("model", () => {
 			id: 1,
 			title: "this is a test",
 			authors: [
-				Object.assign(new Account(), { id: 52, name: "John Doe", email: "test@test.test", createdAt: new Date("2022-08-07T08:47:01.000Z"), active: true, }),
+				Object.assign(new Account(), {
-				Object.assign(new Account(), { id: 4, name: "Tester", email: "another@test.test", createdAt: new Date("2022-09-07T18:32:55.000Z"), active: false, }),
+					id: 52,
+					name: "John Doe",
+					email: "test@test.test",
+					createdAt: new Date("2022-08-07T08:47:01.000Z"),
+					active: true,
+				}),
+				Object.assign(new Account(), {
+					id: 4,
+					name: "Tester",
+					email: "another@test.test",
+					createdAt: new Date("2022-09-07T18:32:55.000Z"),
+					active: false,
+				}),
 			],
 			text: "this is a long test.",
 			evaluation: 8.52,
-			tags: [ {name: "test"}, {name: "foo"} ],
+			tags: [{name: "test"}, {name: "foo"}],
 			comments: [
-				Object.assign(new ArticleComment(), { id: 542, author: Object.assign(new Account(), { id: 52, name: "John Doe", email: "test@test.test", createdAt: new Date("2022-08-07T08:47:01.000Z"), active: true, }), message: "comment content", }),
+				Object.assign(new ArticleComment(), {
+					id: 542,
+					author: Object.assign(new Account(), {
+						id: 52,
+						name: "John Doe",
+						email: "test@test.test",
+						createdAt: new Date("2022-08-07T08:47:01.000Z"),
+						active: true,
+					}),
+					message: "comment content",
+				}),
 			],
 		});
 
-		const deserializedArticle = Article.model.parse({
+		const deserializedArticle = ArticleModel.parse({
 			id: 1,
 			title: "this is a test",
 			authors: [
-				{ id: 52, name: "John Doe", email: "test@test.test", createdAt: "2022-08-07T08:47:01.000Z", active: true, },
+				{
-				{ id: 4, name: "Tester", email: "another@test.test", createdAt: "2022-09-07T18:32:55.000Z", active: false, },
+					id: 52,
+					name: "John Doe",
+					email: "test@test.test",
+					createdAt: "2022-08-07T08:47:01.000Z",
+					active: true,
+				},
+				{
+					id: 4,
+					name: "Tester",
+					email: "another@test.test",
+					createdAt: "2022-09-07T18:32:55.000Z",
+					active: false,
+				},
 			],
 			text: "this is a long test.",
 			evaluation: "8.52",
-			tags: [ {name: "test"}, {name: "foo"} ],
+			tags: [{name: "test"}, {name: "foo"}],
 			comments: [
-				{ id: 542, author: { id: 52, name: "John Doe", email: "test@test.test", createdAt: "2022-08-07T08:47:01.000Z", active: true, }, message: "comment content", },
+				{
+					id: 542,
+					author: {
+						id: 52,
+						name: "John Doe",
+						email: "test@test.test",
+						createdAt: "2022-08-07T08:47:01.000Z",
+						active: true,
+					},
+					message: "comment content",
+				},
 			],
 		});
 
-		const deserializedArticleProperties = Article.model.model(deserializedArticle).getInstanceProperties();
+		const deserializedArticleProperties =
+			ArticleModel.model(deserializedArticle).getInstanceProperties();
 		delete deserializedArticleProperties.authors[0]._sharkitek;
 		delete deserializedArticleProperties.authors[1]._sharkitek;
 		delete deserializedArticleProperties.comments[0]._sharkitek;
 		delete (deserializedArticleProperties.comments[0].author as any)._sharkitek;
-		const expectedArticleProperties = Article.model.model(expectedArticle).getInstanceProperties();
+		const expectedArticleProperties =
+			ArticleModel.model(expectedArticle).getInstanceProperties();
 		delete expectedArticleProperties.authors[0]._sharkitek;
 		delete expectedArticleProperties.authors[1]._sharkitek;
 		delete expectedArticleProperties.comments[0]._sharkitek;
@@ -201,79 +267,126 @@ describe("model", () => {
 
 	it("serializes an initialized model", () => {
 		const article = getTestArticle();
-		expect(Article.model.model(article).serialize()).toEqual({
+		expect(ArticleModel.model(article).serialize()).toEqual({
 			id: 1,
 			title: "this is a test",
 			text: "this is a long test.",
 			evaluation: "25.23",
-			tags: [{ name: "test" }, { name: "foo" }],
+			tags: [{name: "test"}, {name: "foo"}],
 			authors: [
-				{ id: 52, createdAt: article.authors[0].createdAt.toISOString(), name: "John Doe", email: "john@doe.test", active: true }
+				{
+					id: 52,
+					createdAt: article.authors[0].createdAt.toISOString(),
+					name: "John Doe",
+					email: "john@doe.test",
+					active: true,
+				},
 			],
 			comments: [],
 		});
 	});
 
 	it("deserializes, changes and patches", () => {
-		const deserializedArticle = Article.model.parse({
+		const deserializedArticle = ArticleModel.parse({
 			id: 1,
 			title: "this is a test",
 			authors: [
-				{ id: 52, name: "John Doe", email: "test@test.test", createdAt: "2022-08-07T08:47:01.000Z", active: true, },
+				{
-				{ id: 4, name: "Tester", email: "another@test.test", createdAt: "2022-09-07T18:32:55.000Z", active: false, },
+					id: 52,
+					name: "John Doe",
+					email: "test@test.test",
+					createdAt: "2022-08-07T08:47:01.000Z",
+					active: true,
+				},
+				{
+					id: 4,
+					name: "Tester",
+					email: "another@test.test",
+					createdAt: "2022-09-07T18:32:55.000Z",
+					active: false,
+				},
 			],
 			text: "this is a long test.",
 			evaluation: "8.52",
-			tags: [ {name: "test"}, {name: "foo"} ],
+			tags: [{name: "test"}, {name: "foo"}],
 			comments: [
-				{ id: 542, author: { id: 52, name: "John Doe", email: "test@test.test", createdAt: "2022-08-07T08:47:01.000Z", active: true, }, message: "comment content", },
+				{
+					id: 542,
+					author: {
+						id: 52,
+						name: "John Doe",
+						email: "test@test.test",
+						createdAt: "2022-08-07T08:47:01.000Z",
+						active: true,
+					},
+					message: "comment content",
+				},
 			],
 		});
 
 		deserializedArticle.text = "A new text for a new life!";
 
-		expect(Article.model.model(deserializedArticle).patch()).toStrictEqual({
+		expect(ArticleModel.model(deserializedArticle).patch()).toStrictEqual({
 			id: 1,
 			text: "A new text for a new life!",
 		});
 
 		deserializedArticle.evaluation = 5.24;
 
-		expect(Article.model.model(deserializedArticle).patch()).toStrictEqual({
+		expect(ArticleModel.model(deserializedArticle).patch()).toStrictEqual({
 			id: 1,
 			evaluation: "5.24",
 		});
 	});
 
 	it("patches with modified submodels", () => {
-		const deserializedArticle = Article.model.parse({
+		const deserializedArticle = ArticleModel.parse({
 			id: 1,
 			title: "this is a test",
 			authors: [
-				{ id: 52, name: "John Doe", email: "test@test.test", createdAt: "2022-08-07T08:47:01.000Z", active: true, },
+				{
-				{ id: 4, name: "Tester", email: "another@test.test", createdAt: "2022-09-07T18:32:55.000Z", active: false, },
+					id: 52,
+					name: "John Doe",
+					email: "test@test.test",
+					createdAt: "2022-08-07T08:47:01.000Z",
+					active: true,
+				},
+				{
+					id: 4,
+					name: "Tester",
+					email: "another@test.test",
+					createdAt: "2022-09-07T18:32:55.000Z",
+					active: false,
+				},
 			],
 			text: "this is a long test.",
 			evaluation: "8.52",
-			tags: [ {name: "test"}, {name: "foo"} ],
+			tags: [{name: "test"}, {name: "foo"}],
 			comments: [
-				{ id: 542, author: { id: 52, name: "John Doe", email: "test@test.test", createdAt: "2022-08-07T08:47:01.000Z", active: true, }, message: "comment content", },
+				{
+					id: 542,
+					author: {
+						id: 52,
+						name: "John Doe",
+						email: "test@test.test",
+						createdAt: "2022-08-07T08:47:01.000Z",
+						active: true,
+					},
+					message: "comment content",
+				},
 			],
 		});
 
 		deserializedArticle.authors[1].active = true;
 
-		expect(Article.model.model(deserializedArticle).patch()).toStrictEqual({
+		expect(ArticleModel.model(deserializedArticle).patch()).toStrictEqual({
 			id: 1,
-			authors: [
+			authors: [{id: 52}, {id: 4, active: true}],
-				{ id: 52, },
-				{ id: 4, active: true },
-			],
 		});
 
 		deserializedArticle.comments[0].author.name = "Johnny";
 
-		expect(Article.model.model(deserializedArticle).patch()).toStrictEqual({
+		expect(ArticleModel.model(deserializedArticle).patch()).toStrictEqual({
 			id: 1,
 			comments: [
 				{
@@ -288,8 +401,7 @@ describe("model", () => {
 	});
 
 	it("deserializes and patches with fields that are not properties", () => {
-		class TestModel
+		class TestModel {
-		{
 			static model = defineModel({
 				Class: TestModel,
 				properties: {
@@ -297,12 +409,12 @@ describe("model", () => {
 					label: s.property.string(),
 				},
 				identifier: "id",
-			})
+			});
 
 			id: number;
 			label: string;
 
-			notAProperty: { hello: string } = { hello: "world" };
+			notAProperty: {hello: string} = {hello: "world"};
 		}
 
 		const deserializedModel = TestModel.model.parse({
@@ -313,17 +425,163 @@ describe("model", () => {
 		expect(deserializedModel.label).toBe("testing");
 		expect(deserializedModel.notAProperty?.hello).toBe("world");
 
-		const clonedDeserializedModel = TestModel.model.model(deserializedModel).clone();
+		const clonedDeserializedModel = TestModel.model
+			.model(deserializedModel)
+			.clone();
 
 		deserializedModel.label = "new!";
-		expect(TestModel.model.model(deserializedModel).patch()).toStrictEqual({ id: 5, label: "new!" });
+		expect(TestModel.model.model(deserializedModel).patch()).toStrictEqual({
+			id: 5,
+			label: "new!",
+		});
 
 		deserializedModel.notAProperty.hello = "monster";
-		expect(TestModel.model.model(deserializedModel).patch()).toStrictEqual({ id: 5 });
+		expect(TestModel.model.model(deserializedModel).patch()).toStrictEqual({
+			id: 5,
+		});
 
-		expect(TestModel.model.model(deserializedModel).serialize()).toStrictEqual({ id: 5, label: "new!" });
+		expect(TestModel.model.model(deserializedModel).serialize()).toStrictEqual({
+			id: 5,
+			label: "new!",
+		});
 
-		expect(TestModel.model.model(clonedDeserializedModel).serialize()).toStrictEqual({ id: 5, label: "testing" });
+		expect(
+			TestModel.model.model(clonedDeserializedModel).serialize(),
+		).toStrictEqual({id: 5, label: "testing"});
 		expect(clonedDeserializedModel.notAProperty.hello).toEqual("world");
 	});
+
+	it("assigns properties, ignoring fields which are not properties", () => {
+		const deserializedArticle = ArticleModel.parse({
+			id: 1,
+			title: "this is a test",
+			authors: [
+				{
+					id: 52,
+					name: "John Doe",
+					email: "test@test.test",
+					createdAt: "2022-08-07T08:47:01.000Z",
+					active: true,
+				},
+				{
+					id: 4,
+					name: "Tester",
+					email: "another@test.test",
+					createdAt: "2022-09-07T18:32:55.000Z",
+					active: false,
+				},
+			],
+			text: "this is a long test.",
+			evaluation: "8.52",
+			tags: [{name: "test"}, {name: "foo"}],
+			comments: [
+				{
+					id: 542,
+					author: {
+						id: 52,
+						name: "John Doe",
+						email: "test@test.test",
+						createdAt: "2022-08-07T08:47:01.000Z",
+						active: true,
+					},
+					message: "comment content",
+				},
+			],
+		});
+
+		// Assign title and text, html is silently ignored.
+		ArticleModel.model(deserializedArticle).assign({
+			title: "something else",
+			text: "fully new text! yes!",
+			html: "<p>fully new text! yes!</p>",
+		});
+		expect((deserializedArticle as any)?.html).toBeUndefined();
+		expect(ArticleModel.model(deserializedArticle).patch()).toStrictEqual({
+			id: 1,
+			title: "something else",
+			text: "fully new text! yes!",
+		});
+	});
+
+	it("initializes a model from properties values", () => {
+		const testArticle = ArticleModel.from({
+			title: "this is a test",
+			authors: [
+				AccountModel.from({
+					name: "John Doe",
+					email: "test@test.test",
+					createdAt: new Date(),
+					active: true,
+				}),
+			],
+			text: "this is a long text",
+			evaluation: 8.52,
+			tags: [{name: "test"}, {name: "foo"}],
+
+			unknownField: true,
+			anotherOne: "test",
+		});
+
+		expect(testArticle.title).toBe("this is a test");
+		expect(testArticle.text).toBe("this is a long text");
+		expect(testArticle.evaluation).toBe(8.52);
+		expect(testArticle.authors).toHaveLength(1);
+		expect(testArticle.authors[0]?.name).toBe("John Doe");
+		expect((testArticle as any).unknownField).toBeUndefined();
+		expect((testArticle as any).anotherOne).toBeUndefined();
+	});
+
+	it("applies patches to an existing model", () => {
+		const testArticle = ArticleModel.from({
+			id: 1,
+			title: "this is a test",
+			authors: [
+				AccountModel.from({
+					id: 55,
+					name: "John Doe",
+					email: "test@test.test",
+					createdAt: new Date(),
+					active: true,
+				}),
+			],
+			text: "this is a long text",
+			evaluation: 8.52,
+			tags: [{name: "test"}, {name: "foo"}],
+
+			unknownField: true,
+			anotherOne: "test",
+		});
+		ArticleModel.model(testArticle).resetDiff();
+
+		// Test simple patch.
+		ArticleModel.model(testArticle).applyPatch({
+			title: "new title",
+		});
+		expect(testArticle.title).toBe("new title");
+		expect(ArticleModel.model(testArticle).serializeDiff()).toStrictEqual({
+			id: 1,
+		});
+
+		// Test originals update propagation.
+		ArticleModel.model(testArticle).applyPatch({
+			authors: [{email: "john@test.test"}],
+		});
+		expect(testArticle.authors[0].email).toBe("john@test.test");
+		expect(ArticleModel.model(testArticle).serializeDiff()).toStrictEqual({
+			id: 1,
+		});
+
+		// Test without originals update.
+		ArticleModel.model(testArticle).applyPatch(
+			{
+				authors: [{name: "Johnny"}],
+			},
+			false,
+		);
+		expect(testArticle.authors[0].name).toBe("Johnny");
+		expect(ArticleModel.model(testArticle).serializeDiff()).toStrictEqual({
+			id: 1,
+			authors: [{id: 55, name: "Johnny"}],
+		});
+	});
 });

tests/model/types/array.test.ts

@@ -1,8 +1,7 @@
 import {describe, expect, test} from "vitest";
 import {ArrayType, InvalidTypeValueError, s} from "../../../src/library";
 
-class TestModel
+class TestModel {
-{
 	id: number;
 	name: string;
 	price: number;
@@ -19,119 +18,423 @@ describe("array type", () => {
 		identifier: "id",
 	});
 
-	test("array type definition", () => {
+	test("definition", () => {
 		const arrayType = s.property.array(s.property.model(testModel));
 		expect(arrayType.type).toBeInstanceOf(ArrayType);
 	});
 
 	const testProperty = s.property.array(s.property.decimal());
 
-	test("array type functions", () => {
+	describe("serialize", () => {
-		expect(testProperty.type.serialize([12.547, 8, -52.11])).toEqual(["12.547", "8", "-52.11"]);
+		test("serialize", () => {
-		expect(testProperty.type.deserialize(["12.547", "8", "-52.11"])).toEqual([12.547, 8, -52.11]);
+			expect(testProperty.type.serialize([12.547, 8, -52.11])).toEqual([
-
+				"12.547",
-		{ // Try to serialize the difference of an array with one changed model.
+				"8",
-			const propertyValue = [
+				"-52.11",
-				testModel.model(Object.assign(new TestModel(), { id: 1, name: "test", price: 22 })).instance,
-				testModel.model(Object.assign(new TestModel(), { id: 2, name: "another", price: 12.55 })).instance,
-			];
-			propertyValue[0].name = "new";
-			expect(s.property.array(s.property.model(testModel)).type.serializeDiff(propertyValue)).toEqual([
-				{ id: 1, name: "new" },
-				{ id: 2 },
 			]);
-		}
 
 			expect(testProperty.type.serialize(null)).toBe(null);
-		expect(testProperty.type.deserialize(null)).toBe(null);
-		expect(testProperty.type.serializeDiff(null)).toBe(null);
-
 			expect(testProperty.type.serialize(undefined)).toBe(undefined);
-		expect(testProperty.type.deserialize(undefined)).toBe(undefined);
+		});
-		expect(testProperty.type.serializeDiff(undefined)).toBe(undefined);
 
-		expect(testProperty.type.hasChanged([12.547, 8, -52.11], [12.547, 8, -52.11])).toBeFalsy();
+		test("invalid parameters", () => {
+			expect(() => testProperty.type.serialize({} as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+		});
+	});
+
+	describe("deserialize", () => {
+		test("deserialize", () => {
+			expect(testProperty.type.deserialize(["12.547", "8", "-52.11"])).toEqual([
+				12.547, 8, -52.11,
+			]);
+
+			expect(testProperty.type.deserialize(null)).toBe(null);
+			expect(testProperty.type.deserialize(undefined)).toBe(undefined);
+		});
+
+		test("invalid parameters", () => {
+			expect(() => testProperty.type.deserialize({} as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+		});
+	});
+
+	describe("serializeDiff", () => {
+		test("serializeDiff", () => {
+			{
+				// Try to serialize the difference of an array with one changed model.
+				const propertyValue = [
+					testModel.model(
+						Object.assign(new TestModel(), {id: 1, name: "test", price: 22}),
+					).instance,
+					testModel.model(
+						Object.assign(new TestModel(), {
+							id: 2,
+							name: "another",
+							price: 12.55,
+						}),
+					).instance,
+				];
+				propertyValue[0].name = "new";
+				expect(
+					s.property
+						.array(s.property.model(testModel))
+						.type.serializeDiff(propertyValue),
+				).toEqual([{id: 1, name: "new"}, {id: 2}]);
+			}
+
+			expect(testProperty.type.serializeDiff(null)).toBe(null);
+			expect(testProperty.type.serializeDiff(undefined)).toBe(undefined);
+		});
+
+		test("invalid parameters", () => {
+			expect(() => testProperty.type.serializeDiff({} as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+		});
+	});
+
+	describe("hasChanged", () => {
+		test("hasChanged", () => {
+			expect(
+				testProperty.type.hasChanged([12.547, 8, -52.11], [12.547, 8, -52.11]),
+			).toBeFalsy();
 			expect(testProperty.type.hasChanged(null, null)).toBeFalsy();
 			expect(testProperty.type.hasChanged(undefined, undefined)).toBeFalsy();
 			expect(testProperty.type.hasChanged(null, undefined)).toBeTruthy();
 			expect(testProperty.type.hasChanged(undefined, null)).toBeTruthy();
-		expect(testProperty.type.hasChanged(null, [12.547, 8, -52.11])).toBeTruthy();
+			expect(
-		expect(testProperty.type.hasChanged(undefined, [12.547, 8, -52.11])).toBeTruthy();
+				testProperty.type.hasChanged(null, [12.547, 8, -52.11]),
-		expect(testProperty.type.hasChanged([12.547, 8, -52.11], null)).toBeTruthy();
+			).toBeTruthy();
-		expect(testProperty.type.hasChanged([12.547, 8, -52.11], undefined)).toBeTruthy();
+			expect(
-		expect(testProperty.type.hasChanged([12.547, 8, -52.11], [12.547, -52.11, 8])).toBeTruthy();
+				testProperty.type.hasChanged(undefined, [12.547, 8, -52.11]),
-		expect(testProperty.type.hasChanged([12.547, -52.11, 8], [12.547, 8, -52.11])).toBeTruthy();
+			).toBeTruthy();
-		expect(testProperty.type.hasChanged([12.547, 8, -52.11], [12.547, 8])).toBeTruthy();
+			expect(
-		expect(testProperty.type.hasChanged([12.547, 8], [12.547, 8, -52.11])).toBeTruthy();
+				testProperty.type.hasChanged([12.547, 8, -52.11], null),
+			).toBeTruthy();
+			expect(
+				testProperty.type.hasChanged([12.547, 8, -52.11], undefined),
+			).toBeTruthy();
+			expect(
+				testProperty.type.hasChanged([12.547, 8, -52.11], [12.547, -52.11, 8]),
+			).toBeTruthy();
+			expect(
+				testProperty.type.hasChanged([12.547, -52.11, 8], [12.547, 8, -52.11]),
+			).toBeTruthy();
+			expect(
+				testProperty.type.hasChanged([12.547, 8, -52.11], [12.547, 8]),
+			).toBeTruthy();
+			expect(
+				testProperty.type.hasChanged([12.547, 8], [12.547, 8, -52.11]),
+			).toBeTruthy();
+		});
 
-		expect(testProperty.type.serializedHasChanged(["12.547", "8", "-52.11"], ["12.547", "8", "-52.11"])).toBeFalsy();
+		test("invalid parameters", () => {
+			expect(testProperty.type.hasChanged({} as any, {} as any)).toBeTruthy();
+			expect(
+				testProperty.type.hasChanged(false as any, false as any),
+			).toBeFalsy();
+		});
+	});
+
+	describe("serializedHasChanged", () => {
+		test("serializedHasChanged", () => {
+			expect(
+				testProperty.type.serializedHasChanged(
+					["12.547", "8", "-52.11"],
+					["12.547", "8", "-52.11"],
+				),
+			).toBeFalsy();
 			expect(testProperty.type.serializedHasChanged(null, null)).toBeFalsy();
-		expect(testProperty.type.serializedHasChanged(undefined, undefined)).toBeFalsy();
+			expect(
-		expect(testProperty.type.serializedHasChanged(null, undefined)).toBeTruthy();
+				testProperty.type.serializedHasChanged(undefined, undefined),
-		expect(testProperty.type.serializedHasChanged(undefined, null)).toBeTruthy();
+			).toBeFalsy();
-		expect(testProperty.type.serializedHasChanged(null, ["12.547", "8", "-52.11"])).toBeTruthy();
+			expect(
-		expect(testProperty.type.serializedHasChanged(undefined, ["12.547", "8", "-52.11"])).toBeTruthy();
+				testProperty.type.serializedHasChanged(null, undefined),
-		expect(testProperty.type.serializedHasChanged(["12.547", "8", "-52.11"], null)).toBeTruthy();
+			).toBeTruthy();
-		expect(testProperty.type.serializedHasChanged(["12.547", "8", "-52.11"], undefined)).toBeTruthy();
+			expect(
-		expect(testProperty.type.serializedHasChanged(["12.547", "8", "-52.11"], ["12.547", "-52.11", "8"])).toBeTruthy();
+				testProperty.type.serializedHasChanged(undefined, null),
-		expect(testProperty.type.serializedHasChanged(["12.547", "-52.11", "8"], ["12.547", "8", "-52.11"])).toBeTruthy();
+			).toBeTruthy();
-		expect(testProperty.type.serializedHasChanged(["12.547", "8", "-52.11"], ["12.547", "8"])).toBeTruthy();
+			expect(
-		expect(testProperty.type.serializedHasChanged(["12.547", "8"], ["12.547", "8", "-52.11"])).toBeTruthy();
+				testProperty.type.serializedHasChanged(null, ["12.547", "8", "-52.11"]),
+			).toBeTruthy();
+			expect(
+				testProperty.type.serializedHasChanged(undefined, [
+					"12.547",
+					"8",
+					"-52.11",
+				]),
+			).toBeTruthy();
+			expect(
+				testProperty.type.serializedHasChanged(["12.547", "8", "-52.11"], null),
+			).toBeTruthy();
+			expect(
+				testProperty.type.serializedHasChanged(
+					["12.547", "8", "-52.11"],
+					undefined,
+				),
+			).toBeTruthy();
+			expect(
+				testProperty.type.serializedHasChanged(
+					["12.547", "8", "-52.11"],
+					["12.547", "-52.11", "8"],
+				),
+			).toBeTruthy();
+			expect(
+				testProperty.type.serializedHasChanged(
+					["12.547", "-52.11", "8"],
+					["12.547", "8", "-52.11"],
+				),
+			).toBeTruthy();
+			expect(
+				testProperty.type.serializedHasChanged(
+					["12.547", "8", "-52.11"],
+					["12.547", "8"],
+				),
+			).toBeTruthy();
+			expect(
+				testProperty.type.serializedHasChanged(
+					["12.547", "8"],
+					["12.547", "8", "-52.11"],
+				),
+			).toBeTruthy();
+		});
 
-		{ // Try to reset the difference of an array with one changed model.
+		test("invalid parameters", () => {
+			expect(
+				testProperty.type.serializedHasChanged({} as any, {} as any),
+			).toBeTruthy();
+			expect(
+				testProperty.type.serializedHasChanged(false as any, false as any),
+			).toBeFalsy();
+		});
+	});
+
+	describe("resetDiff", () => {
+		test("resetDiff", () => {
+			{
+				// Try to reset the difference of an array with one changed model.
 				const propertyValue = [
-				testModel.model(Object.assign(new TestModel(), { id: 1, name: "test", price: 22 })).instance,
+					testModel.model(
-				testModel.model(Object.assign(new TestModel(), { id: 2, name: "another", price: 12.55 })).instance,
+						Object.assign(new TestModel(), {id: 1, name: "test", price: 22}),
+					).instance,
+					testModel.model(
+						Object.assign(new TestModel(), {
+							id: 2,
+							name: "another",
+							price: 12.55,
+						}),
+					).instance,
 				];
 				propertyValue[0].name = "new";
-			expect(s.property.array(s.property.model(testModel)).type.serializeDiff(propertyValue)).toEqual([
+				expect(
-				{ id: 1, name: "new" },
+					s.property
-				{ id: 2 },
+						.array(s.property.model(testModel))
-			]);
+						.type.serializeDiff(propertyValue),
-			s.property.array(s.property.model(testModel)).type.resetDiff(propertyValue)
+				).toEqual([{id: 1, name: "new"}, {id: 2}]);
-			expect(s.property.array(s.property.model(testModel)).type.serializeDiff(propertyValue)).toEqual([
+				s.property
-				{ id: 1 },
+					.array(s.property.model(testModel))
-				{ id: 2 },
+					.type.resetDiff(propertyValue);
-			]);
+				expect(
+					s.property
+						.array(s.property.model(testModel))
+						.type.serializeDiff(propertyValue),
+				).toEqual([{id: 1}, {id: 2}]);
 			}
+
 			testProperty.type.resetDiff(undefined);
 			testProperty.type.resetDiff(null);
+		});
 
-		{ // Test that values are cloned in a different array.
+		test("invalid parameters", () => {
+			expect(() => testProperty.type.resetDiff({} as any)).not.toThrow();
+		});
+	});
+
+	describe("clone", () => {
+		test("clone", () => {
+			{
+				// Test that values are cloned in a different array.
 				const propertyValue = [12.547, 8, -52.11];
 				const clonedPropertyValue = testProperty.type.clone(propertyValue);
 				expect(clonedPropertyValue).not.toBe(propertyValue);
 				expect(clonedPropertyValue).toEqual(propertyValue);
 			}
-		{ // Test that values are cloned recursively.
+			{
+				// Test that values are cloned recursively.
 				const propertyValue = [
-				testModel.model(Object.assign(new TestModel(), { id: 1, name: "test", price: 22 })).instance,
+					testModel.model(
-				testModel.model(Object.assign(new TestModel(), { id: 2, name: "another", price: 12.55 })).instance,
+						Object.assign(new TestModel(), {id: 1, name: "test", price: 22}),
+					).instance,
+					testModel.model(
+						Object.assign(new TestModel(), {
+							id: 2,
+							name: "another",
+							price: 12.55,
+						}),
+					).instance,
 				];
 
 				// The arrays are different.
-			const clonedPropertyValue = s.property.array(s.property.model(testModel)).type.clone(propertyValue);
+				const clonedPropertyValue = s.property
+					.array(s.property.model(testModel))
+					.type.clone(propertyValue);
 				expect(clonedPropertyValue).not.toBe(propertyValue);
 
 				// Array values must be different objects but have the same values.
 				expect(clonedPropertyValue[0]).not.toBe(propertyValue[0]);
 				expect(clonedPropertyValue[1]).not.toBe(propertyValue[1]);
-			expect(testModel.model(clonedPropertyValue[0]).getInstanceProperties()).toEqual(testModel.model(propertyValue[0]).getInstanceProperties());
+				expect(
-			expect(testModel.model(clonedPropertyValue[1]).getInstanceProperties()).toEqual(testModel.model(propertyValue[1]).getInstanceProperties());
+					testModel.model(clonedPropertyValue[0]).getInstanceProperties(),
+				).toEqual(testModel.model(propertyValue[0]).getInstanceProperties());
+				expect(
+					testModel.model(clonedPropertyValue[1]).getInstanceProperties(),
+				).toEqual(testModel.model(propertyValue[1]).getInstanceProperties());
 			}
+
 			expect(testProperty.type.clone(undefined)).toBe(undefined);
 			expect(testProperty.type.clone(null)).toBe(null);
 		});
 
-	test("invalid parameters types", () => {
+		test("invalid parameters", () => {
-		expect(() => testProperty.type.serialize({} as any)).toThrowError(InvalidTypeValueError);
+			expect(() => testProperty.type.clone({} as any)).toThrowError(
-		expect(() => testProperty.type.deserialize({} as any)).toThrowError(InvalidTypeValueError);
+				InvalidTypeValueError,
-		expect(() => testProperty.type.serializeDiff({} as any)).toThrowError(InvalidTypeValueError);
+			);
-		expect(() => testProperty.type.resetDiff({} as any)).not.toThrow();
+		});
-		expect(testProperty.type.hasChanged({} as any, {} as any)).toBeTruthy();
+	});
-		expect(testProperty.type.hasChanged(false as any, false as any)).toBeFalsy();
+
-		expect(testProperty.type.serializedHasChanged({} as any, {} as any)).toBeTruthy();
+	test("applyPatch", () => {
-		expect(testProperty.type.serializedHasChanged(false as any, false as any)).toBeFalsy();
+		{
-		expect(() => testProperty.type.clone({} as any)).toThrowError(InvalidTypeValueError);
+			// Test simple patch.
+			expect(
+				testProperty.type.applyPatch(
+					[12.547, 8, -52.11],
+					["12.547", "444.34", "-52.11"],
+					true,
+				),
+			).toEqual([12.547, 444.34, -52.11]);
+			expect(
+				testProperty.type.applyPatch(
+					undefined,
+					["12.547", "444.34", "-52.11"],
+					false,
+				),
+			).toEqual([12.547, 444.34, -52.11]);
+			expect(
+				testProperty.type.applyPatch(
+					null,
+					["12.547", "444.34", "-52.11"],
+					false,
+				),
+			).toEqual([12.547, 444.34, -52.11]);
+			expect(
+				testProperty.type.applyPatch([12.547, 8, -52.11], undefined, false),
+			).toBeUndefined();
+			expect(
+				testProperty.type.applyPatch([12.547, 8, -52.11], null, false),
+			).toBeNull();
+		}
+		{
+			// Invalid patch.
+			expect(() =>
+				testProperty.type.applyPatch([12.547, 8, -52.11], {} as any, false),
+			).toThrow(InvalidTypeValueError);
+		}
+		{
+			// Test recursive patch.
+			const propertyValue = [
+				testModel.model(
+					Object.assign(new TestModel(), {id: 1, name: "test", price: 22}),
+				).instance,
+				testModel.model(
+					Object.assign(new TestModel(), {
+						id: 2,
+						name: "another",
+						price: 12.55,
+					}),
+				).instance,
+			];
+
+			const patched = s.property
+				.array(s.property.model(testModel))
+				.type.applyPatch(
+					propertyValue,
+					[
+						{
+							id: 1,
+							name: "new",
+						},
+						{
+							id: 2,
+							price: "13.65",
+						},
+					],
+					true,
+				);
+
+			// Check applied patch.
+			expect(patched).toEqual([
+				testModel.parse({id: 1, name: "new", price: "22"}),
+				testModel.parse({id: 2, name: "another", price: "13.65"}),
+			]);
+
+			// Check that originals have been updated.
+			expect(testModel.model(patched[0]).serializeDiff()).toEqual({id: 1});
+			patched[0].name = "test";
+			expect(testModel.model(patched[0]).serializeDiff()).toEqual({
+				id: 1,
+				name: "test",
+			});
+			expect(testModel.model(patched[1]).serializeDiff()).toEqual({id: 2});
+			patched[1].price = 12.55;
+			expect(testModel.model(patched[1]).serializeDiff()).toEqual({
+				id: 2,
+				price: "12.55",
+			});
+		}
+		{
+			// Test recursive patch without originals update.-
+			const propertyValue = [
+				testModel.model(
+					Object.assign(new TestModel(), {id: 1, name: "test", price: 22}),
+				).instance,
+				testModel.model(
+					Object.assign(new TestModel(), {
+						id: 2,
+						name: "another",
+						price: 12.55,
+					}),
+				).instance,
+			];
+
+			const patched = s.property
+				.array(s.property.model(testModel))
+				.type.applyPatch(
+					propertyValue,
+					[
+						{
+							id: 1,
+							name: "new",
+						},
+						{
+							id: 2,
+							price: "13.65",
+						},
+					],
+					false,
+				);
+
+			// Check that originals haven't been updated.
+			expect(testModel.model(patched[0]).serializeDiff()).toEqual({
+				id: 1,
+				name: "new",
+			});
+			expect(testModel.model(patched[1]).serializeDiff()).toEqual({
+				id: 2,
+				price: "13.65",
+			});
+		}
 	});
 });

tests/model/types/boolean.test.ts

@@ -2,7 +2,7 @@ import {describe, expect, test} from "vitest";
 import {BooleanType, s} from "../../../src/library";
 
 describe("boolean type", () => {
-	test("boolean type definition", () => {
+	test("definition", () => {
 		{
 			const booleanType = s.property.boolean();
 			expect(booleanType.type).toBeInstanceOf(BooleanType);
@@ -13,56 +13,163 @@ describe("boolean type", () => {
 		}
 	});
 
-	test("boolean type functions", () => {
+	describe("serialize", () => {
+		test("serialize", () => {
 			expect(s.property.boolean().type.serialize(false)).toBe(false);
-		expect(s.property.boolean().type.deserialize(false)).toBe(false);
-		expect(s.property.boolean().type.serializeDiff(true)).toBe(true);
-
 			expect(s.property.boolean().type.serialize(null)).toBe(null);
-		expect(s.property.boolean().type.deserialize(null)).toBe(null);
-		expect(s.property.boolean().type.serializeDiff(null)).toBe(null);
-
 			expect(s.property.boolean().type.serialize(undefined)).toBe(undefined);
-		expect(s.property.boolean().type.deserialize(undefined)).toBe(undefined);
+		});
-		expect(s.property.boolean().type.serializeDiff(undefined)).toBe(undefined);
 
+		test("invalid parameters", () => {
+			expect(s.property.boolean().type.serialize(1 as any)).toBeTruthy();
+			expect(s.property.boolean().type.serialize(0 as any)).toBeFalsy();
+		});
+	});
+
+	describe("deserialize", () => {
+		test("deserialize", () => {
+			expect(s.property.boolean().type.deserialize(false)).toBe(false);
+			expect(s.property.boolean().type.deserialize(null)).toBe(null);
+			expect(s.property.boolean().type.deserialize(undefined)).toBe(undefined);
+		});
+
+		test("invalid parameters", () => {
+			expect(s.property.boolean().type.deserialize(1 as any)).toBeTruthy();
+			expect(s.property.boolean().type.deserialize(0 as any)).toBeFalsy();
+		});
+	});
+
+	describe("serializeDiff", () => {
+		test("serializeDiff", () => {
+			expect(s.property.boolean().type.serializeDiff(true)).toBe(true);
+			expect(s.property.boolean().type.serializeDiff(null)).toBe(null);
+			expect(s.property.boolean().type.serializeDiff(undefined)).toBe(
+				undefined,
+			);
+		});
+
+		test("invalid parameters", () => {
+			expect(s.property.boolean().type.serializeDiff(1 as any)).toBeTruthy();
+			expect(s.property.boolean().type.serializeDiff(0 as any)).toBeFalsy();
+		});
+	});
+
+	describe("hasChanged", () => {
+		test("hasChanged", () => {
 			expect(s.property.boolean().type.hasChanged(true, true)).toBeFalsy();
 			expect(s.property.boolean().type.hasChanged(null, null)).toBeFalsy();
-		expect(s.property.boolean().type.hasChanged(undefined, undefined)).toBeFalsy();
+			expect(
-		expect(s.property.boolean().type.hasChanged(null, undefined)).toBeTruthy();
+				s.property.boolean().type.hasChanged(undefined, undefined),
-		expect(s.property.boolean().type.hasChanged(undefined, null)).toBeTruthy();
+			).toBeFalsy();
+			expect(
+				s.property.boolean().type.hasChanged(null, undefined),
+			).toBeTruthy();
+			expect(
+				s.property.boolean().type.hasChanged(undefined, null),
+			).toBeTruthy();
 			expect(s.property.boolean().type.hasChanged(null, false)).toBeTruthy();
-		expect(s.property.boolean().type.hasChanged(undefined, false)).toBeTruthy();
+			expect(
+				s.property.boolean().type.hasChanged(undefined, false),
+			).toBeTruthy();
 			expect(s.property.boolean().type.hasChanged(false, null)).toBeTruthy();
-		expect(s.property.boolean().type.hasChanged(false, undefined)).toBeTruthy();
+			expect(
+				s.property.boolean().type.hasChanged(false, undefined),
+			).toBeTruthy();
+		});
 
-		expect(s.property.boolean().type.serializedHasChanged(false, false)).toBeFalsy();
+		test("invalid parameters", () => {
-		expect(s.property.boolean().type.serializedHasChanged(null, null)).toBeFalsy();
+			expect(
-		expect(s.property.boolean().type.serializedHasChanged(undefined, undefined)).toBeFalsy();
+				s.property.boolean().type.hasChanged({} as any, {} as any),
-		expect(s.property.boolean().type.serializedHasChanged(null, undefined)).toBeTruthy();
+			).toBeTruthy();
-		expect(s.property.boolean().type.serializedHasChanged(undefined, null)).toBeTruthy();
+			expect(
-		expect(s.property.boolean().type.serializedHasChanged(null, false)).toBeTruthy();
+				s.property.boolean().type.hasChanged(false as any, false as any),
-		expect(s.property.boolean().type.serializedHasChanged(undefined, false)).toBeTruthy();
+			).toBeFalsy();
-		expect(s.property.boolean().type.serializedHasChanged(false, null)).toBeTruthy();
+		});
-		expect(s.property.boolean().type.serializedHasChanged(false, undefined)).toBeTruthy();
+	});
 
+	describe("serializedHasChanged", () => {
+		test("serializedHasChanged", () => {
+			expect(
+				s.property.boolean().type.serializedHasChanged(false, false),
+			).toBeFalsy();
+			expect(
+				s.property.boolean().type.serializedHasChanged(null, null),
+			).toBeFalsy();
+			expect(
+				s.property.boolean().type.serializedHasChanged(undefined, undefined),
+			).toBeFalsy();
+			expect(
+				s.property.boolean().type.serializedHasChanged(null, undefined),
+			).toBeTruthy();
+			expect(
+				s.property.boolean().type.serializedHasChanged(undefined, null),
+			).toBeTruthy();
+			expect(
+				s.property.boolean().type.serializedHasChanged(null, false),
+			).toBeTruthy();
+			expect(
+				s.property.boolean().type.serializedHasChanged(undefined, false),
+			).toBeTruthy();
+			expect(
+				s.property.boolean().type.serializedHasChanged(false, null),
+			).toBeTruthy();
+			expect(
+				s.property.boolean().type.serializedHasChanged(false, undefined),
+			).toBeTruthy();
+		});
+
+		test("invalid parameters", () => {
+			expect(
+				s.property.boolean().type.serializedHasChanged({} as any, {} as any),
+			).toBeTruthy();
+			expect(
+				s.property
+					.boolean()
+					.type.serializedHasChanged(false as any, false as any),
+			).toBeFalsy();
+		});
+	});
+
+	describe("resetDiff", () => {
+		test("resetDiff", () => {
 			s.property.boolean().type.resetDiff(false);
 			s.property.boolean().type.resetDiff(undefined);
 			s.property.boolean().type.resetDiff(null);
 		});
 
-	test("invalid parameters types", () => {
+		test("resetDiff", () => {
-		expect(s.property.boolean().type.serialize(1 as any)).toBeTruthy();
+			expect(() =>
-		expect(s.property.boolean().type.serialize(0 as any)).toBeFalsy();
+				s.property.boolean().type.resetDiff({} as any),
-		expect(s.property.boolean().type.deserialize(1 as any)).toBeTruthy();
+			).not.toThrow();
-		expect(s.property.boolean().type.deserialize(0 as any)).toBeFalsy();
+		});
-		expect(s.property.boolean().type.serializeDiff(1 as any)).toBeTruthy();
+	});
-		expect(s.property.boolean().type.serializeDiff(0 as any)).toBeFalsy();
+
-		expect(() => s.property.boolean().type.resetDiff({} as any)).not.toThrow();
+	describe("clone", () => {
-		expect(s.property.boolean().type.hasChanged({} as any, {} as any)).toBeTruthy();
+		test("invalid parameters", () => {
-		expect(s.property.boolean().type.hasChanged(false as any, false as any)).toBeFalsy();
-		expect(s.property.boolean().type.serializedHasChanged({} as any, {} as any)).toBeTruthy();
-		expect(s.property.boolean().type.serializedHasChanged(false as any, false as any)).toBeFalsy();
 			expect(s.property.boolean().type.clone({} as any)).toStrictEqual({});
 		});
+	});
+
+	test("applyPatch", () => {
+		expect(
+			s.property.boolean().type.applyPatch(false, true, true),
+		).toBeTruthy();
+		expect(
+			s.property.boolean().type.applyPatch(false, true, false),
+		).toBeTruthy();
+		expect(
+			s.property.boolean().type.applyPatch(true, false, false),
+		).toBeFalsy();
+		expect(
+			s.property.boolean().type.applyPatch(false, undefined, false),
+		).toBeUndefined();
+		expect(s.property.boolean().type.applyPatch(false, null, false)).toBeNull();
+		expect(
+			s.property.boolean().type.applyPatch(undefined, null, false),
+		).toBeNull();
+		expect(s.property.boolean().type.applyPatch(null, null, false)).toBeNull();
+		expect(
+			s.property.boolean().type.applyPatch(null, false, false),
+		).toBeFalsy();
+	});
 });

tests/model/types/date.test.ts

@@ -4,71 +4,229 @@ import {DateType, InvalidTypeValueError, s} from "../../../src/library";
 describe("date type", () => {
 	const testDate = new Date();
 
-	test("date type definition", () => {
+	test("definition", () => {
 		const dateType = s.property.date();
 		expect(dateType.type).toBeInstanceOf(DateType);
 	});
 
-	test("date type functions", () => {
+	describe("serialize", () => {
-		expect(s.property.date().type.serialize(testDate)).toBe(testDate.toISOString());
+		test("serialize", () => {
-		expect(s.property.date().type.deserialize(testDate.toISOString())?.getTime()).toBe(testDate.getTime());
+			expect(s.property.date().type.serialize(testDate)).toBe(
-		expect(s.property.date().type.serializeDiff(new Date(testDate))).toBe(testDate.toISOString());
+				testDate.toISOString(),
-		expect(s.property.date().type.deserialize("2565152-2156121-256123121 5121544175:21515612").valueOf()).toBeNaN();
+			);
-		expect(s.property.date().type.serialize(new Date(NaN))).toBe((new Date(NaN)).toString());
+
+			expect(s.property.date().type.serialize(new Date(NaN))).toBe(
+				new Date(NaN).toString(),
+			);
 
 			expect(s.property.date().type.serialize(null)).toBe(null);
-		expect(s.property.date().type.deserialize(null)).toBe(null);
-		expect(s.property.date().type.serializeDiff(null)).toBe(null);
-
 			expect(s.property.date().type.serialize(undefined)).toBe(undefined);
-		expect(s.property.date().type.deserialize(undefined)).toBe(undefined);
+		});
-		expect(s.property.date().type.serializeDiff(undefined)).toBe(undefined);
 
-		expect(s.property.date().type.hasChanged(testDate, new Date(testDate))).toBeFalsy();
+		test("invalid parameters", () => {
+			expect(() => s.property.date().type.serialize({} as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+		});
+	});
+
+	describe("deserialize", () => {
+		test("deserialize", () => {
+			expect(
+				s.property.date().type.deserialize(testDate.toISOString())?.getTime(),
+			).toBe(testDate.getTime());
+
+			expect(
+				s.property
+					.date()
+					.type.deserialize("2565152-2156121-256123121 5121544175:21515612")
+					.valueOf(),
+			).toBeNaN();
+
+			expect(s.property.date().type.deserialize(null)).toBe(null);
+			expect(s.property.date().type.deserialize(undefined)).toBe(undefined);
+		});
+
+		test("invalid parameters", () => {
+			expect(
+				s.property
+					.date()
+					.type.deserialize({} as any)
+					.getTime(),
+			).toBe(NaN);
+		});
+	});
+
+	describe("serializeDiff", () => {
+		test("serializeDiff", () => {
+			expect(s.property.date().type.serializeDiff(new Date(testDate))).toBe(
+				testDate.toISOString(),
+			);
+
+			expect(s.property.date().type.serializeDiff(null)).toBe(null);
+			expect(s.property.date().type.serializeDiff(undefined)).toBe(undefined);
+		});
+
+		test("invalid parameters", () => {
+			expect(() =>
+				s.property.date().type.serializeDiff({} as any),
+			).toThrowError(InvalidTypeValueError);
+		});
+	});
+
+	describe("hasChanged", () => {
+		test("hasChanged", () => {
+			expect(
+				s.property.date().type.hasChanged(testDate, new Date(testDate)),
+			).toBeFalsy();
 			expect(s.property.date().type.hasChanged(null, null)).toBeFalsy();
-		expect(s.property.date().type.hasChanged(undefined, undefined)).toBeFalsy();
+			expect(
+				s.property.date().type.hasChanged(undefined, undefined),
+			).toBeFalsy();
 			expect(s.property.date().type.hasChanged(null, undefined)).toBeTruthy();
 			expect(s.property.date().type.hasChanged(undefined, null)).toBeTruthy();
 			expect(s.property.date().type.hasChanged(null, testDate)).toBeTruthy();
-		expect(s.property.date().type.hasChanged(undefined, testDate)).toBeTruthy();
+			expect(
+				s.property.date().type.hasChanged(undefined, testDate),
+			).toBeTruthy();
 			expect(s.property.date().type.hasChanged(testDate, null)).toBeTruthy();
-		expect(s.property.date().type.hasChanged(new Date(NaN), null)).toBeTruthy();
+			expect(
-		expect(s.property.date().type.hasChanged(new Date(NaN), undefined)).toBeTruthy();
+				s.property.date().type.hasChanged(new Date(NaN), null),
-		expect(s.property.date().type.hasChanged(new Date(NaN), new Date(NaN))).toBeFalsy();
+			).toBeTruthy();
+			expect(
+				s.property.date().type.hasChanged(new Date(NaN), undefined),
+			).toBeTruthy();
+			expect(
+				s.property.date().type.hasChanged(new Date(NaN), new Date(NaN)),
+			).toBeFalsy();
+		});
 
-		expect(s.property.date().type.serializedHasChanged(testDate.toISOString(), (new Date(testDate)).toISOString())).toBeFalsy();
+		test("invalid parameters", () => {
-		expect(s.property.date().type.serializedHasChanged(null, null)).toBeFalsy();
+			expect(
-		expect(s.property.date().type.serializedHasChanged(undefined, undefined)).toBeFalsy();
+				s.property.date().type.hasChanged({} as any, {} as any),
-		expect(s.property.date().type.serializedHasChanged(null, undefined)).toBeTruthy();
+			).toBeTruthy();
-		expect(s.property.date().type.serializedHasChanged(undefined, null)).toBeTruthy();
+			expect(
-		expect(s.property.date().type.serializedHasChanged(null, testDate.toISOString())).toBeTruthy();
+				s.property.date().type.hasChanged(false as any, false as any),
-		expect(s.property.date().type.serializedHasChanged(undefined, testDate.toISOString())).toBeTruthy();
+			).toBeFalsy();
-		expect(s.property.date().type.serializedHasChanged(testDate.toISOString(), null)).toBeTruthy();
+		});
-		expect(s.property.date().type.serializedHasChanged((new Date(NaN)).toString(), null)).toBeTruthy();
+	});
-		expect(s.property.date().type.serializedHasChanged((new Date(NaN)).toString(), undefined)).toBeTruthy();
-		expect(s.property.date().type.serializedHasChanged((new Date(NaN)).toString(), (new Date(NaN)).toString())).toBeFalsy();
 
+	describe("serializedHasChanged", () => {
+		test("serializedHasChanged", () => {
+			expect(
+				s.property
+					.date()
+					.type.serializedHasChanged(
+						testDate.toISOString(),
+						new Date(testDate).toISOString(),
+					),
+			).toBeFalsy();
+			expect(
+				s.property.date().type.serializedHasChanged(null, null),
+			).toBeFalsy();
+			expect(
+				s.property.date().type.serializedHasChanged(undefined, undefined),
+			).toBeFalsy();
+			expect(
+				s.property.date().type.serializedHasChanged(null, undefined),
+			).toBeTruthy();
+			expect(
+				s.property.date().type.serializedHasChanged(undefined, null),
+			).toBeTruthy();
+			expect(
+				s.property
+					.date()
+					.type.serializedHasChanged(null, testDate.toISOString()),
+			).toBeTruthy();
+			expect(
+				s.property
+					.date()
+					.type.serializedHasChanged(undefined, testDate.toISOString()),
+			).toBeTruthy();
+			expect(
+				s.property
+					.date()
+					.type.serializedHasChanged(testDate.toISOString(), null),
+			).toBeTruthy();
+			expect(
+				s.property
+					.date()
+					.type.serializedHasChanged(new Date(NaN).toString(), null),
+			).toBeTruthy();
+			expect(
+				s.property
+					.date()
+					.type.serializedHasChanged(new Date(NaN).toString(), undefined),
+			).toBeTruthy();
+			expect(
+				s.property
+					.date()
+					.type.serializedHasChanged(
+						new Date(NaN).toString(),
+						new Date(NaN).toString(),
+					),
+			).toBeFalsy();
+		});
+
+		test("invalid parameters", () => {
+			expect(
+				s.property.date().type.serializedHasChanged({} as any, {} as any),
+			).toBeTruthy();
+			expect(
+				s.property.date().type.serializedHasChanged(false as any, false as any),
+			).toBeFalsy();
+			expect(s.property.date().type.clone({} as any)).toStrictEqual({});
+		});
+	});
+
+	describe("resetDiff", () => {
+		test("resetDiff", () => {
 			s.property.date().type.resetDiff(testDate);
 			s.property.date().type.resetDiff(undefined);
 			s.property.date().type.resetDiff(null);
+		});
 
-		{ // Test that the date is cloned in a different object.
+		test("invalid parameters", () => {
+			expect(() => s.property.date().type.resetDiff({} as any)).not.toThrow();
+		});
+	});
+
+	test("clone", () => {
+		// Test that the date is cloned in a different object.
 		const propertyValue = new Date();
 		const clonedPropertyValue = s.property.date().type.clone(propertyValue);
 		expect(clonedPropertyValue).not.toBe(propertyValue);
 		expect(clonedPropertyValue).toEqual(propertyValue);
-		}
 	});
 
-	test("invalid parameters types", () => {
+	test("applyPatch", () => {
-		expect(() => s.property.date().type.serialize({} as any)).toThrowError(InvalidTypeValueError);
+		expect(
-		expect(s.property.date().type.deserialize({} as any).getTime()).toBe(NaN);
+			s.property
-		expect(() => s.property.date().type.serializeDiff({} as any)).toThrowError(InvalidTypeValueError);
+				.date()
-		expect(() => s.property.date().type.resetDiff({} as any)).not.toThrow();
+				.type.applyPatch(new Date("2022-02-22"), testDate.toISOString(), false)
-		expect(s.property.date().type.hasChanged({} as any, {} as any)).toBeTruthy();
+				?.getTime(),
-		expect(s.property.date().type.hasChanged(false as any, false as any)).toBeFalsy();
+		).toBe(testDate.getTime());
-		expect(s.property.date().type.serializedHasChanged({} as any, {} as any)).toBeTruthy();
+		expect(
-		expect(s.property.date().type.serializedHasChanged(false as any, false as any)).toBeFalsy();
+			s.property
-		expect(s.property.date().type.clone({} as any)).toStrictEqual({});
+				.date()
+				.type.applyPatch(null, testDate.toISOString(), true)
+				?.getTime(),
+		).toBe(testDate.getTime());
+		expect(
+			s.property
+				.date()
+				.type.applyPatch(
+					undefined,
+					"2565152-2156121-256123121 5121544175:21515612",
+					false,
+				)
+				.valueOf(),
+		).toBeNaN();
+		expect(
+			s.property.date().type.applyPatch(new Date(), undefined, false),
+		).toBeUndefined();
+		expect(
+			s.property.date().type.applyPatch(new Date(), null, false),
+		).toBeNull();
 	});
 });

tests/model/types/decimal.test.ts

@@ -7,54 +7,158 @@ describe("decimal type", () => {
 		expect(decimalType.type).toBeInstanceOf(DecimalType);
 	});
 
-	test("decimal type functions", () => {
+	describe("serialize", () => {
+		test("serialize", () => {
 			expect(s.property.decimal().type.serialize(5.257)).toBe("5.257");
-		expect(s.property.decimal().type.deserialize("5.257")).toBe(5.257);
-		expect(s.property.decimal().type.serializeDiff(542)).toBe("542");
 
 			expect(s.property.decimal().type.serialize(null)).toBe(null);
-		expect(s.property.decimal().type.deserialize(null)).toBe(null);
-		expect(s.property.decimal().type.serializeDiff(null)).toBe(null);
-
 			expect(s.property.decimal().type.serialize(undefined)).toBe(undefined);
+		});
+
+		test("invalid parameters", () => {
+			expect(() => s.property.decimal().type.serialize({} as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+		});
+	});
+
+	describe("deserialize", () => {
+		test("deserialize", () => {
+			expect(s.property.decimal().type.deserialize("5.257")).toBe(5.257);
+			expect(s.property.decimal().type.deserialize(null)).toBe(null);
 			expect(s.property.decimal().type.deserialize(undefined)).toBe(undefined);
-		expect(s.property.decimal().type.serializeDiff(undefined)).toBe(undefined);
+		});
 
-		expect(s.property.decimal().type.hasChanged(5.257, 5.257)).toBeFalsy();
+		test("invalid parameters", () => {
-		expect(s.property.decimal().type.hasChanged(null, null)).toBeFalsy();
+			expect(s.property.decimal().type.deserialize({} as any)).toBe(NaN);
-		expect(s.property.decimal().type.hasChanged(undefined, undefined)).toBeFalsy();
+			expect(s.property.decimal().type.deserialize({} as any)).toBe(NaN);
-		expect(s.property.decimal().type.hasChanged(null, undefined)).toBeTruthy();
+		});
-		expect(s.property.decimal().type.hasChanged(undefined, null)).toBeTruthy();
+	});
-		expect(s.property.decimal().type.hasChanged(null, 5.257)).toBeTruthy();
-		expect(s.property.decimal().type.hasChanged(undefined, 5.257)).toBeTruthy();
-		expect(s.property.decimal().type.hasChanged(5.257, null)).toBeTruthy();
-		expect(s.property.decimal().type.hasChanged(5.257, undefined)).toBeTruthy();
 
-		expect(s.property.decimal().type.serializedHasChanged("5.257", "5.257")).toBeFalsy();
+	describe("serializeDiff", () => {
-		expect(s.property.decimal().type.serializedHasChanged(null, null)).toBeFalsy();
+		test("serializeDiff", () => {
-		expect(s.property.decimal().type.serializedHasChanged(undefined, undefined)).toBeFalsy();
+			expect(s.property.decimal().type.serializeDiff(542)).toBe("542");
-		expect(s.property.decimal().type.serializedHasChanged(null, undefined)).toBeTruthy();
-		expect(s.property.decimal().type.serializedHasChanged(undefined, null)).toBeTruthy();
-		expect(s.property.decimal().type.serializedHasChanged(null, "5.257")).toBeTruthy();
-		expect(s.property.decimal().type.serializedHasChanged(undefined, "5.257")).toBeTruthy();
-		expect(s.property.decimal().type.serializedHasChanged("5.257", null)).toBeTruthy();
-		expect(s.property.decimal().type.serializedHasChanged("5.257", undefined)).toBeTruthy();
 
+			expect(s.property.decimal().type.serializeDiff(null)).toBe(null);
+			expect(s.property.decimal().type.serializeDiff(undefined)).toBe(
+				undefined,
+			);
+		});
+
+		test("invalid parameters", () => {
+			expect(() =>
+				s.property.decimal().type.serializeDiff({} as any),
+			).toThrowError(InvalidTypeValueError);
+		});
+	});
+
+	describe("resetDiff", () => {
+		test("resetDiff", () => {
 			s.property.decimal().type.resetDiff(5.257);
 			s.property.decimal().type.resetDiff(undefined);
 			s.property.decimal().type.resetDiff(null);
 		});
 
-	test("invalid parameters types", () => {
+		test("invalid parameters", () => {
-		expect(() => s.property.decimal().type.serialize({} as any)).toThrowError(InvalidTypeValueError);
+			expect(() =>
-		expect(s.property.decimal().type.deserialize({} as any)).toBe(NaN);
+				s.property.decimal().type.resetDiff({} as any),
-		expect(s.property.decimal().type.deserialize({} as any)).toBe(NaN);
+			).not.toThrow();
-		expect(() => s.property.decimal().type.serializeDiff({} as any)).toThrowError(InvalidTypeValueError);
+		});
-		expect(() => s.property.decimal().type.resetDiff({} as any)).not.toThrow();
+	});
-		expect(s.property.decimal().type.hasChanged({} as any, {} as any)).toBeTruthy();
+
-		expect(s.property.decimal().type.hasChanged(false as any, false as any)).toBeFalsy();
+	describe("hasChanged", () => {
-		expect(s.property.decimal().type.serializedHasChanged({} as any, {} as any)).toBeTruthy();
+		test("hasChanged", () => {
-		expect(s.property.decimal().type.serializedHasChanged(false as any, false as any)).toBeFalsy();
+			expect(s.property.decimal().type.hasChanged(5.257, 5.257)).toBeFalsy();
+			expect(s.property.decimal().type.hasChanged(null, null)).toBeFalsy();
+			expect(
+				s.property.decimal().type.hasChanged(undefined, undefined),
+			).toBeFalsy();
+			expect(
+				s.property.decimal().type.hasChanged(null, undefined),
+			).toBeTruthy();
+			expect(
+				s.property.decimal().type.hasChanged(undefined, null),
+			).toBeTruthy();
+			expect(s.property.decimal().type.hasChanged(null, 5.257)).toBeTruthy();
+			expect(
+				s.property.decimal().type.hasChanged(undefined, 5.257),
+			).toBeTruthy();
+			expect(s.property.decimal().type.hasChanged(5.257, null)).toBeTruthy();
+			expect(
+				s.property.decimal().type.hasChanged(5.257, undefined),
+			).toBeTruthy();
+		});
+
+		test("invalid parameters", () => {
+			expect(
+				s.property.decimal().type.hasChanged({} as any, {} as any),
+			).toBeTruthy();
+			expect(
+				s.property.decimal().type.hasChanged(false as any, false as any),
+			).toBeFalsy();
+		});
+	});
+
+	describe("serializedHasChanged", () => {
+		test("serializedHasChanged", () => {
+			expect(
+				s.property.decimal().type.serializedHasChanged("5.257", "5.257"),
+			).toBeFalsy();
+			expect(
+				s.property.decimal().type.serializedHasChanged(null, null),
+			).toBeFalsy();
+			expect(
+				s.property.decimal().type.serializedHasChanged(undefined, undefined),
+			).toBeFalsy();
+			expect(
+				s.property.decimal().type.serializedHasChanged(null, undefined),
+			).toBeTruthy();
+			expect(
+				s.property.decimal().type.serializedHasChanged(undefined, null),
+			).toBeTruthy();
+			expect(
+				s.property.decimal().type.serializedHasChanged(null, "5.257"),
+			).toBeTruthy();
+			expect(
+				s.property.decimal().type.serializedHasChanged(undefined, "5.257"),
+			).toBeTruthy();
+			expect(
+				s.property.decimal().type.serializedHasChanged("5.257", null),
+			).toBeTruthy();
+			expect(
+				s.property.decimal().type.serializedHasChanged("5.257", undefined),
+			).toBeTruthy();
+		});
+
+		test("invalid parameters", () => {
+			expect(
+				s.property.decimal().type.serializedHasChanged({} as any, {} as any),
+			).toBeTruthy();
+			expect(
+				s.property
+					.decimal()
+					.type.serializedHasChanged(false as any, false as any),
+			).toBeFalsy();
+		});
+	});
+
+	describe("clone", () => {
+		test("invalid parameters", () => {
 			expect(s.property.decimal().type.clone({} as any)).toStrictEqual({});
 		});
+	});
+
+	test("applyPatch", () => {
+		expect(s.property.decimal().type.applyPatch(1, "5.257", false)).toBe(5.257);
+		expect(s.property.decimal().type.applyPatch(undefined, "5.257", true)).toBe(
+			5.257,
+		);
+		expect(s.property.decimal().type.applyPatch(null, "5.257", false)).toBe(
+			5.257,
+		);
+		expect(
+			s.property.decimal().type.applyPatch(5.257, undefined, false),
+		).toBeUndefined();
+		expect(s.property.decimal().type.applyPatch(5.257, null, false)).toBeNull();
+	});
 });

tests/model/types/map.test.ts

@@ -0,0 +1,283 @@
+import {describe, expect, test} from "vitest";
+import {InvalidTypeValueError, s} from "../../../src/library";
+import {MapType} from "../../../src/model/types/map";
+
+describe("map type", () => {
+	test("definition", () => {
+		const mapType = s.property.map(s.property.string(), s.property.numeric());
+		expect(mapType.type).toBeInstanceOf(MapType);
+	});
+
+	const testProperty = s.property.map(
+		s.property.string(),
+		s.property.decimal(),
+	);
+	const testMapValue = new Map<string, number>();
+	testMapValue.set("test", 1.52);
+	testMapValue.set("another", 55);
+
+	describe("serialize", () => {
+		test("serialize", () => {
+			expect(testProperty.type.serialize(testMapValue)).toEqual({
+				test: "1.52",
+				another: "55",
+			});
+
+			expect(testProperty.type.serialize(null)).toEqual(null);
+			expect(testProperty.type.serialize(undefined)).toEqual(undefined);
+		});
+
+		test("invalid parameters", () => {
+			expect(() => testProperty.type.serialize(5 as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+			expect(() => testProperty.type.serialize([] as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+			expect(() => testProperty.type.serialize({} as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+		});
+	});
+
+	describe("deserialize", () => {
+		test("deserialize", () => {
+			expect(
+				testProperty.type.deserialize({
+					test: "1.52",
+					another: "55",
+				}),
+			).toEqual(testMapValue);
+
+			expect(testProperty.type.deserialize(null)).toEqual(null);
+			expect(testProperty.type.deserialize(undefined)).toEqual(undefined);
+		});
+
+		test("invalid parameters", () => {
+			expect(() => testProperty.type.deserialize(5 as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+			expect(() => testProperty.type.deserialize([] as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+		});
+	});
+
+	describe("serializeDiff", () => {
+		test("serializeDiff", () => {
+			expect(testProperty.type.serializeDiff(testMapValue)).toEqual({
+				test: "1.52",
+				another: "55",
+			});
+
+			expect(testProperty.type.serializeDiff(null)).toEqual(null);
+			expect(testProperty.type.serializeDiff(undefined)).toEqual(undefined);
+		});
+
+		test("invalid parameters", () => {
+			expect(() => testProperty.type.serializeDiff(5 as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+			expect(() => testProperty.type.serializeDiff([] as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+			expect(() => testProperty.type.serializeDiff({} as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+		});
+	});
+
+	describe("hasChanged", () => {
+		test("hasChanged", () => {
+			const anotherTestMapValue = new Map<string, number>();
+			anotherTestMapValue.set("test", 1.52);
+			anotherTestMapValue.set("another", 55);
+			expect(
+				testProperty.type.hasChanged(testMapValue, anotherTestMapValue),
+			).toBeFalsy();
+			anotherTestMapValue.set("test", 1.521);
+			expect(
+				testProperty.type.hasChanged(testMapValue, anotherTestMapValue),
+			).toBeTruthy();
+			anotherTestMapValue.delete("test");
+			expect(
+				testProperty.type.hasChanged(testMapValue, anotherTestMapValue),
+			).toBeTruthy();
+			expect(testProperty.type.hasChanged(null, null)).toBeFalsy();
+			expect(testProperty.type.hasChanged(undefined, undefined)).toBeFalsy();
+			expect(testProperty.type.hasChanged(null, undefined)).toBeTruthy();
+			expect(testProperty.type.hasChanged(undefined, null)).toBeTruthy();
+			expect(testProperty.type.hasChanged(null, testMapValue)).toBeTruthy();
+			expect(
+				testProperty.type.hasChanged(undefined, testMapValue),
+			).toBeTruthy();
+			expect(testProperty.type.hasChanged(testMapValue, null)).toBeTruthy();
+			expect(
+				testProperty.type.hasChanged(testMapValue, undefined),
+			).toBeTruthy();
+		});
+	});
+
+	describe("serializedHasChanged", () => {
+		test("serializedHasChanged", () => {
+			expect(
+				testProperty.type.serializedHasChanged(
+					{test: "1.52", another: "55"},
+					{test: "1.52", another: "55"},
+				),
+			).toBeFalsy();
+			expect(
+				testProperty.type.serializedHasChanged(
+					{test: "1.52", another: "55"},
+					{test: "1.521", another: "55"},
+				),
+			).toBeTruthy();
+			expect(
+				testProperty.type.serializedHasChanged(
+					{test: "1.52", another: "55"},
+					{another: "55"},
+				),
+			).toBeTruthy();
+			expect(testProperty.type.serializedHasChanged(null, null)).toBeFalsy();
+			expect(
+				testProperty.type.serializedHasChanged(undefined, undefined),
+			).toBeFalsy();
+			expect(
+				testProperty.type.serializedHasChanged(null, undefined),
+			).toBeTruthy();
+			expect(
+				testProperty.type.serializedHasChanged(undefined, null),
+			).toBeTruthy();
+			expect(
+				testProperty.type.serializedHasChanged(null, {
+					test: "1.52",
+					another: "55",
+				}),
+			).toBeTruthy();
+			expect(
+				testProperty.type.serializedHasChanged(undefined, {
+					test: "1.52",
+					another: "55",
+				}),
+			).toBeTruthy();
+			expect(
+				testProperty.type.serializedHasChanged(
+					{test: "1.52", another: "55"},
+					null,
+				),
+			).toBeTruthy();
+			expect(
+				testProperty.type.serializedHasChanged(
+					{test: "1.52", another: "55"},
+					undefined,
+				),
+			).toBeTruthy();
+		});
+	});
+
+	describe("resetDiff", () => {
+		test("resetDiff", () => {
+			testProperty.type.resetDiff(testMapValue);
+			testProperty.type.resetDiff(undefined);
+			testProperty.type.resetDiff(null);
+		});
+	});
+
+	describe("clone", () => {
+		test("clone", () => {
+			{
+				// Test that keys and values are cloned in a different map.
+				const clonedTestMapValue = testProperty.type.clone(testMapValue);
+				expect(clonedTestMapValue).not.toBe(testMapValue);
+				expect(clonedTestMapValue).toEqual(testMapValue);
+			}
+			{
+				// Test that values are cloned in a different object.
+				const propertyValue = new Map();
+				propertyValue.set("test", [12, 11]);
+				const clonedPropertyValue = s.property
+					.stringMap(s.property.array(s.property.numeric()))
+					.type.clone(propertyValue);
+				expect(clonedPropertyValue).not.toBe(propertyValue);
+				expect(clonedPropertyValue).toEqual(propertyValue);
+				expect(clonedPropertyValue.get("test")).not.toBe(
+					propertyValue.get("test"),
+				);
+				expect(clonedPropertyValue.get("test")).toEqual(
+					propertyValue.get("test"),
+				);
+			}
+			expect(testProperty.type.clone(undefined)).toBe(undefined);
+			expect(testProperty.type.clone(null)).toBe(null);
+		});
+
+		test("invalid parameters", () => {
+			expect(() => testProperty.type.clone(5 as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+			expect(() => testProperty.type.clone([] as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+			expect(() => testProperty.type.clone({} as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+		});
+	});
+
+	test("applyPatch", () => {
+		{
+			// Apply a patch with undefined / NULL values.
+			expect(
+				testProperty.type.applyPatch(testMapValue, undefined, false),
+			).toBeUndefined();
+			expect(testProperty.type.applyPatch(testMapValue, null, true)).toBeNull();
+		}
+
+		{
+			// Invalid patch.
+			expect(() =>
+				testProperty.type.applyPatch(testMapValue, 5416 as any, false),
+			).toThrow(InvalidTypeValueError);
+		}
+
+		{
+			// Apply a patch.
+			{
+				const objectInstance = testProperty.type.applyPatch(
+					testMapValue,
+					{test: "1.521"},
+					true,
+				);
+
+				const expectedMapValue = new Map<string, number>();
+				expectedMapValue.set("test", 1.521);
+				expectedMapValue.set("another", 55);
+				expect(objectInstance).toStrictEqual(expectedMapValue);
+			}
+
+			{
+				const objectInstance = testProperty.type.applyPatch(
+					undefined,
+					{test: "1.52"},
+					false,
+				);
+
+				const expectedMapValue = new Map<string, number>();
+				expectedMapValue.set("test", 1.52);
+				expect(objectInstance).toStrictEqual(expectedMapValue);
+			}
+
+			{
+				const objectInstance = testProperty.type.applyPatch(
+					null,
+					{test: "1.52"},
+					false,
+				);
+
+				const expectedMapValue = new Map<string, number>();
+				expectedMapValue.set("test", 1.52);
+				expect(objectInstance).toStrictEqual(expectedMapValue);
+			}
+		}
+	});
+});

tests/model/types/model.test.ts

@@ -1,8 +1,7 @@
 import {describe, expect, test} from "vitest";
 import {InvalidTypeValueError, ModelType, s} from "../../../src/library";
 
-class TestModel
+class TestModel {
-{
 	id: number;
 	name: string;
 	price: number;
@@ -19,114 +18,565 @@ describe("model type", () => {
 		identifier: "id",
 	});
 
-	test("model type definition", () => {
+	test("definition", () => {
 		const modelType = s.property.model(testModel);
 		expect(modelType.type).toBeInstanceOf(ModelType);
 	});
 
-	test("model type functions", () => {
+	describe("serialize", () => {
-		{ // Try to serialize / deserialize.
+		test("serialize", () => {
-			const testModelInstance = testModel.model(Object.assign(new TestModel(), { id: 1, name: "test", price: 12.548777 })).instance;
+			const testModelInstance = testModel.model(
-			expect(s.property.model(testModel).type.serialize(testModelInstance)).toEqual({ id: 1, name: "test", price: "12.548777" });
+				Object.assign(new TestModel(), {
-			expect(testModel.model(
+					id: 1,
-				s.property.model(testModel).type.deserialize({ id: 1, name: "test", price: "12.548777" })
+					name: "test",
-			).getInstanceProperties()).toEqual(testModel.model(testModelInstance).getInstanceProperties());
+					price: 12.548777,
-		}
+				}),
+			).instance;
 
-		{ // Try to serialize the difference.
+			expect(
-			const testModelInstance = testModel.model(Object.assign(new TestModel(), { id: 1, name: "test", price: 12.548777 })).instance;
+				s.property.model(testModel).type.serialize(testModelInstance),
-			testModelInstance.name = "new";
+			).toEqual({id: 1, name: "test", price: "12.548777"});
-			expect(s.property.model(testModel).type.serializeDiff(testModelInstance)).toEqual({ id: 1, name: "new" });
-		}
 
 			expect(s.property.model(testModel).type.serialize(null)).toEqual(null);
+			expect(s.property.model(testModel).type.serialize(undefined)).toEqual(
+				undefined,
+			);
+		});
+
+		test("invalid parameters", () => {
+			expect(() =>
+				s.property.model(testModel).type.serialize(5 as any),
+			).toThrowError(InvalidTypeValueError);
+			expect(() =>
+				s.property.model(testModel).type.serialize([] as any),
+			).toThrowError(InvalidTypeValueError);
+			expect(() =>
+				s.property.model(testModel).type.serialize(new (class {})() as any),
+			).toThrowError(InvalidTypeValueError);
+		});
+	});
+
+	describe("deserialize", () => {
+		test("deserialize", () => {
+			const testModelInstance = testModel.model(
+				Object.assign(new TestModel(), {
+					id: 1,
+					name: "test",
+					price: 12.548777,
+				}),
+			).instance;
+
+			expect(
+				testModel
+					.model(
+						s.property
+							.model(testModel)
+							.type.deserialize({id: 1, name: "test", price: "12.548777"}),
+					)
+					.getInstanceProperties(),
+			).toEqual(testModel.model(testModelInstance).getInstanceProperties());
+
 			expect(s.property.model(testModel).type.deserialize(null)).toEqual(null);
-		expect(s.property.model(testModel).type.serializeDiff(null)).toEqual(null);
+			expect(s.property.model(testModel).type.deserialize(undefined)).toEqual(
+				undefined,
+			);
+		});
 
-		expect(s.property.model(testModel).type.serialize(undefined)).toEqual(undefined);
+		test("invalid parameters", () => {
-		expect(s.property.model(testModel).type.deserialize(undefined)).toEqual(undefined);
+			expect(() =>
-		expect(s.property.model(testModel).type.serializeDiff(undefined)).toEqual(undefined);
+				s.property.model(testModel).type.deserialize(5 as any),
+			).toThrowError(InvalidTypeValueError);
+			expect(() =>
+				s.property.model(testModel).type.deserialize([] as any),
+			).toThrowError(InvalidTypeValueError);
+		});
+	});
 
+	describe("serializeDiff", () => {
+		test("serializeDiff", () => {
+			// Try to serialize the difference.
+			const testModelInstance = testModel.model(
+				Object.assign(new TestModel(), {
+					id: 1,
+					name: "test",
+					price: 12.548777,
+				}),
+			).instance;
+
+			testModelInstance.name = "new";
+			expect(
+				s.property.model(testModel).type.serializeDiff(testModelInstance),
+			).toEqual({id: 1, name: "new"});
+
+			expect(s.property.model(testModel).type.serializeDiff(null)).toEqual(
+				null,
+			);
+			expect(s.property.model(testModel).type.serializeDiff(undefined)).toEqual(
+				undefined,
+			);
+		});
+
+		test("invalid parameters", () => {
+			expect(() =>
+				s.property.model(testModel).type.serializeDiff(5 as any),
+			).toThrowError(InvalidTypeValueError);
+			expect(() =>
+				s.property.model(testModel).type.serializeDiff([] as any),
+			).toThrowError(InvalidTypeValueError);
+			expect(() =>
+				s.property.model(testModel).type.serializeDiff(new (class {})() as any),
+			).toThrowError(InvalidTypeValueError);
+		});
+	});
+
+	describe("hasChanged", () => {
+		test("hasChanged", () => {
 			{
-			const testModelInstance = testModel.model(Object.assign(new TestModel(), { id: 1, name: "test", price: 12.548777 })).instance;
+				const testModelInstance = testModel.model(
-			expect(s.property.model(testModel).type.hasChanged(testModelInstance, testModelInstance)).toBeFalsy();
+					Object.assign(new TestModel(), {
+						id: 1,
+						name: "test",
+						price: 12.548777,
+					}),
+				).instance;
+				expect(
+					s.property
+						.model(testModel)
+						.type.hasChanged(testModelInstance, testModelInstance),
+				).toBeFalsy();
 			}
 			{
-			const testModelInstance = testModel.model(Object.assign(new TestModel(), { id: 1, name: "test", price: 12.548777 })).instance;
+				const testModelInstance = testModel.model(
+					Object.assign(new TestModel(), {
+						id: 1,
+						name: "test",
+						price: 12.548777,
+					}),
+				).instance;
 				testModelInstance.price = 12.548778;
-			expect(s.property.model(testModel).type.hasChanged(testModelInstance, testModelInstance)).toBeTruthy();
+				expect(
+					s.property
+						.model(testModel)
+						.type.hasChanged(testModelInstance, testModelInstance),
+				).toBeTruthy();
 			}
-		expect(s.property.model(testModel).type.hasChanged(null, null)).toBeFalsy();
+			expect(
-		expect(s.property.model(testModel).type.hasChanged(undefined, undefined)).toBeFalsy();
+				s.property.model(testModel).type.hasChanged(null, null),
-		expect(s.property.model(testModel).type.hasChanged(null, undefined)).toBeTruthy();
+			).toBeFalsy();
-		expect(s.property.model(testModel).type.hasChanged(undefined, null)).toBeTruthy();
+			expect(
-		expect(s.property.model(testModel).type.hasChanged(null, testModel.model(Object.assign(new TestModel(), { id: 1, name: "test", price: 12.548777 })).instance)).toBeTruthy();
+				s.property.model(testModel).type.hasChanged(undefined, undefined),
-		expect(s.property.model(testModel).type.hasChanged(undefined, testModel.model(Object.assign(new TestModel(), { id: 1, name: "test", price: 12.548777 })).instance)).toBeTruthy();
+			).toBeFalsy();
-		expect(s.property.model(testModel).type.hasChanged(testModel.model(Object.assign(new TestModel(), { id: 1, name: "test", price: 12.548777 })).instance, null)).toBeTruthy();
+			expect(
-		expect(s.property.model(testModel).type.hasChanged(testModel.model(Object.assign(new TestModel(), { id: 1, name: "test", price: 12.548777 })).instance, undefined)).toBeTruthy();
+				s.property.model(testModel).type.hasChanged(null, undefined),
+			).toBeTruthy();
+			expect(
+				s.property.model(testModel).type.hasChanged(undefined, null),
+			).toBeTruthy();
+			expect(
+				s.property.model(testModel).type.hasChanged(
+					null,
+					testModel.model(
+						Object.assign(new TestModel(), {
+							id: 1,
+							name: "test",
+							price: 12.548777,
+						}),
+					).instance,
+				),
+			).toBeTruthy();
+			expect(
+				s.property.model(testModel).type.hasChanged(
+					undefined,
+					testModel.model(
+						Object.assign(new TestModel(), {
+							id: 1,
+							name: "test",
+							price: 12.548777,
+						}),
+					).instance,
+				),
+			).toBeTruthy();
+			expect(
+				s.property.model(testModel).type.hasChanged(
+					testModel.model(
+						Object.assign(new TestModel(), {
+							id: 1,
+							name: "test",
+							price: 12.548777,
+						}),
+					).instance,
+					null,
+				),
+			).toBeTruthy();
+			expect(
+				s.property.model(testModel).type.hasChanged(
+					testModel.model(
+						Object.assign(new TestModel(), {
+							id: 1,
+							name: "test",
+							price: 12.548777,
+						}),
+					).instance,
+					undefined,
+				),
+			).toBeTruthy();
+		});
 
-		expect(s.property.model(testModel).type.serializedHasChanged(
+		test("invalid parameters", () => {
-			{ id: 1, name: "test", price: "12.548777" },
+			expect(() =>
-			{ id: 1, price: "12.548777", name: "test" },
+				s.property.model(testModel).type.hasChanged(5 as any, 5 as any),
-		)).toBeFalsy();
+			).toThrowError(InvalidTypeValueError);
-		expect(s.property.model(testModel).type.serializedHasChanged(
+			expect(() =>
-			{ id: 1, name: "test", price: "12.548777" },
+				s.property
-			{ id: 1, name: "test", price: "12.548778" },
+					.model(testModel)
-		)).toBeTruthy();
+					.type.hasChanged(
-		expect(s.property.model(testModel).type.serializedHasChanged(null, null)).toBeFalsy();
+						testModel.model(new TestModel()).instance,
-		expect(s.property.model(testModel).type.serializedHasChanged(undefined, undefined)).toBeFalsy();
+						[] as any,
-		expect(s.property.model(testModel).type.serializedHasChanged(null, undefined)).toBeTruthy();
+					),
-		expect(s.property.model(testModel).type.serializedHasChanged(undefined, null)).toBeTruthy();
+			).toThrowError(InvalidTypeValueError);
-		expect(s.property.model(testModel).type.serializedHasChanged(null, { id: 1, name: "test", price: "12.548777" })).toBeTruthy();
+			expect(() =>
-		expect(s.property.model(testModel).type.serializedHasChanged(undefined, { id: 1, name: "test", price: "12.548777" })).toBeTruthy();
+				s.property
-		expect(s.property.model(testModel).type.serializedHasChanged({ id: 1, name: "test", price: "12.548777" }, null)).toBeTruthy();
+					.model(testModel)
-		expect(s.property.model(testModel).type.serializedHasChanged({ id: 1, name: "test", price: "12.548777" }, undefined)).toBeTruthy();
+					.type.hasChanged(
+						testModel.model(new TestModel()).instance,
+						new (class {})() as any,
+					),
+			).toThrowError(InvalidTypeValueError);
+		});
+	});
+
+	describe("serializedHasChanged", () => {
+		test("serializedHasChanged", () => {
+			expect(
+				s.property
+					.model(testModel)
+					.type.serializedHasChanged(
+						{id: 1, name: "test", price: "12.548777"},
+						{id: 1, price: "12.548777", name: "test"},
+					),
+			).toBeFalsy();
+			expect(
+				s.property
+					.model(testModel)
+					.type.serializedHasChanged(
+						{id: 1, name: "test", price: "12.548777"},
+						{id: 1, name: "test", price: "12.548778"},
+					),
+			).toBeTruthy();
+			expect(
+				s.property.model(testModel).type.serializedHasChanged(null, null),
+			).toBeFalsy();
+			expect(
+				s.property
+					.model(testModel)
+					.type.serializedHasChanged(undefined, undefined),
+			).toBeFalsy();
+			expect(
+				s.property.model(testModel).type.serializedHasChanged(null, undefined),
+			).toBeTruthy();
+			expect(
+				s.property.model(testModel).type.serializedHasChanged(undefined, null),
+			).toBeTruthy();
+			expect(
+				s.property.model(testModel).type.serializedHasChanged(null, {
+					id: 1,
+					name: "test",
+					price: "12.548777",
+				}),
+			).toBeTruthy();
+			expect(
+				s.property.model(testModel).type.serializedHasChanged(undefined, {
+					id: 1,
+					name: "test",
+					price: "12.548777",
+				}),
+			).toBeTruthy();
+			expect(
+				s.property
+					.model(testModel)
+					.type.serializedHasChanged(
+						{id: 1, name: "test", price: "12.548777"},
+						null,
+					),
+			).toBeTruthy();
+			expect(
+				s.property
+					.model(testModel)
+					.type.serializedHasChanged(
+						{id: 1, name: "test", price: "12.548777"},
+						undefined,
+					),
+			).toBeTruthy();
+		});
+
+		test("invalid parameters", () => {
+			expect(() =>
+				s.property
+					.model(testModel)
+					.type.serializedHasChanged(5 as any, 5 as any),
+			).toThrowError(InvalidTypeValueError);
+			expect(() =>
+				s.property
+					.model(testModel)
+					.type.serializedHasChanged({} as any, [] as any),
+			).toThrowError(InvalidTypeValueError);
+			expect(
+				s.property
+					.model(testModel)
+					.type.serializedHasChanged({} as any, new (class {})() as any),
+			).toBeFalsy();
+		});
+	});
+
+	describe("resetDiff", () => {
+		test("resetDiff", () => {
+			const testModelInstance = testModel.model(
+				Object.assign(new TestModel(), {
+					id: 1,
+					name: "test",
+					price: 12.548777,
+				}),
+			).instance;
 
-		{ // Serializing the difference to check that the difference has been reset.
-			const testModelInstance = testModel.model(Object.assign(new TestModel(), { id: 1, name: "test", price: 12.548777 })).instance;
 			testModelInstance.price = 555.555;
-			expect(testModel.model(testModelInstance).serializeDiff()).toEqual({ id: 1, price: "555.555" });
+			expect(testModel.model(testModelInstance).serializeDiff()).toEqual({
+				id: 1,
+				price: "555.555",
+			});
 			s.property.model(testModel).type.resetDiff(testModelInstance);
-			expect(testModel.model(testModelInstance).serializeDiff()).toEqual({ id: 1 });
+			expect(testModel.model(testModelInstance).serializeDiff()).toEqual({
-		}
+				id: 1,
+			});
 
 			s.property.model(testModel).type.resetDiff(undefined);
 			s.property.model(testModel).type.resetDiff(null);
+		});
 
-		{ // Test that values are cloned in a different model instance.
+		test("invalid parameters", () => {
-			const testModelInstance = testModel.model(Object.assign(new TestModel(), { id: 1, name: "test", price: 12.548777 })).instance;
+			expect(() =>
+				s.property.model(testModel).type.resetDiff(5 as any),
+			).toThrowError(InvalidTypeValueError);
+			expect(() =>
+				s.property.model(testModel).type.resetDiff([] as any),
+			).toThrowError(InvalidTypeValueError);
+			expect(() =>
+				s.property.model(testModel).type.resetDiff(new (class {})() as any),
+			).toThrowError(InvalidTypeValueError);
+		});
+	});
+
+	describe("clone", () => {
+		test("clone", () => {
+			// Test that values are cloned in a different model instance.
+			const testModelInstance = testModel.model(
+				Object.assign(new TestModel(), {
+					id: 1,
+					name: "test",
+					price: 12.548777,
+				}),
+			).instance;
 			testModelInstance.price = 555.555;
-			const clonedModelInstance = s.property.model(testModel).type.clone(testModelInstance);
+			const clonedModelInstance = s.property
+				.model(testModel)
+				.type.clone(testModelInstance);
 			expect(clonedModelInstance).not.toBe(testModelInstance);
-			expect(testModel.model(clonedModelInstance).getInstanceProperties()).toEqual(testModel.model(testModelInstance).getInstanceProperties());
+			expect(
-			expect(testModel.model(clonedModelInstance).serializeDiff()).toEqual(testModel.model(testModelInstance).serializeDiff());
+				testModel.model(clonedModelInstance).getInstanceProperties(),
-		}
+			).toEqual(testModel.model(testModelInstance).getInstanceProperties());
+			expect(testModel.model(clonedModelInstance).serializeDiff()).toEqual(
+				testModel.model(testModelInstance).serializeDiff(),
+			);
+
 			expect(s.property.model(testModel).type.clone(undefined)).toBe(undefined);
 			expect(s.property.model(testModel).type.clone(null)).toBe(null);
 		});
 
-	test("invalid parameters types", () => {
+		test("invalid parameters", () => {
-		expect(() => s.property.model(testModel).type.serialize(5 as any)).toThrowError(InvalidTypeValueError);
+			expect(() =>
-		expect(() => s.property.model(testModel).type.deserialize(5 as any)).toThrowError(InvalidTypeValueError);
+				s.property.model(testModel).type.clone(5 as any),
-		expect(() => s.property.model(testModel).type.serializeDiff(5 as any)).toThrowError(InvalidTypeValueError);
+			).toThrowError(InvalidTypeValueError);
-		expect(() => s.property.model(testModel).type.resetDiff(5 as any)).toThrowError(InvalidTypeValueError);
+			expect(() =>
-		expect(() => s.property.model(testModel).type.hasChanged(5 as any, 5 as any)).toThrowError(InvalidTypeValueError);
+				s.property.model(testModel).type.clone([] as any),
-		expect(() => s.property.model(testModel).type.serializedHasChanged(5 as any, 5 as any)).toThrowError(InvalidTypeValueError);
+			).toThrowError(InvalidTypeValueError);
-		expect(() => s.property.model(testModel).type.clone(5 as any)).toThrowError(InvalidTypeValueError);
+			expect(() =>
+				s.property.model(testModel).type.clone(new (class {})() as any),
+			).toThrowError(InvalidTypeValueError);
+		});
+	});
 
-		expect(() => s.property.model(testModel).type.serialize([] as any)).toThrowError(InvalidTypeValueError);
+	test("applyPatch", () => {
-		expect(() => s.property.model(testModel).type.deserialize([] as any)).toThrowError(InvalidTypeValueError);
+		{
-		expect(() => s.property.model(testModel).type.serializeDiff([] as any)).toThrowError(InvalidTypeValueError);
+			// Apply a patch with undefined / NULL values.
-		expect(() => s.property.model(testModel).type.resetDiff([] as any)).toThrowError(InvalidTypeValueError);
+			expect(
-		expect(() => s.property.model(testModel).type.hasChanged(testModel.model(new TestModel()).instance, [] as any)).toThrowError(InvalidTypeValueError);
+				s.property.model(testModel).type.applyPatch(
-		expect(() => s.property.model(testModel).type.serializedHasChanged({} as any, [] as any)).toThrowError(InvalidTypeValueError);
+					testModel.model(
-		expect(() => s.property.model(testModel).type.clone([] as any)).toThrowError(InvalidTypeValueError);
+						Object.assign(new TestModel(), {
+							id: 1,
+							name: "test",
+							price: 12.548777,
+						}),
+					).instance,
+					undefined,
+					false,
+				),
+			).toBeUndefined();
+			expect(
+				s.property.model(testModel).type.applyPatch(
+					testModel.model(
+						Object.assign(new TestModel(), {
+							id: 1,
+							name: "test",
+							price: 12.548777,
+						}),
+					).instance,
+					null,
+					true,
+				),
+			).toBeNull();
+		}
 
-		expect(() => s.property.model(testModel).type.serialize(new class{} as any)).toThrowError(InvalidTypeValueError);
+		{
-		expect(() => s.property.model(testModel).type.serializeDiff(new class{} as any)).toThrowError(InvalidTypeValueError);
+			// Invalid patch.
-		expect(() => s.property.model(testModel).type.resetDiff(new class{} as any)).toThrowError(InvalidTypeValueError);
+			expect(() =>
-		expect(() => s.property.model(testModel).type.hasChanged(testModel.model(new TestModel()).instance, new class{} as any)).toThrowError(InvalidTypeValueError);
+				s.property.model(testModel).type.applyPatch(
-		expect(s.property.model(testModel).type.serializedHasChanged({} as any, new class{} as any)).toBeFalsy();
+					testModel.model(
-		expect(() => s.property.model(testModel).type.clone(new class{} as any)).toThrowError(InvalidTypeValueError);
+						Object.assign(new TestModel(), {
+							id: 1,
+							name: "test",
+							price: 12.548777,
+						}),
+					).instance,
+					5416 as any,
+					false,
+				),
+			).toThrow(InvalidTypeValueError);
+		}
+
+		{
+			// Apply a patch with originals update.
+			{
+				const modelInstance = s.property.model(testModel).type.applyPatch(
+					testModel.model(
+						Object.assign(new TestModel(), {
+							id: 1,
+							name: "test",
+							price: 12.548777,
+						}),
+					).instance,
+					{id: 1, name: "another"},
+					true,
+				);
+
+				expect(
+					testModel.model(modelInstance).getInstanceProperties(),
+				).toStrictEqual({
+					id: 1,
+					name: "another",
+					price: 12.548777,
+				});
+				expect(testModel.model(modelInstance).serializeDiff()).toStrictEqual({
+					id: 1,
+				});
+			}
+
+			{
+				const modelInstance = s.property
+					.model(testModel)
+					.type.applyPatch(undefined, {id: 1, name: "test"}, true);
+
+				expect(
+					testModel.model(modelInstance).getInstanceProperties(),
+				).toStrictEqual({
+					id: 1,
+					name: "test",
+					price: undefined,
+				});
+				expect(testModel.model(modelInstance).serializeDiff()).toStrictEqual({
+					id: 1,
+				});
+			}
+
+			{
+				const modelInstance = s.property
+					.model(testModel)
+					.type.applyPatch(null, {id: 1, name: "test"}, true);
+
+				expect(
+					testModel.model(modelInstance).getInstanceProperties(),
+				).toStrictEqual({
+					id: 1,
+					name: "test",
+					price: undefined,
+				});
+				expect(testModel.model(modelInstance).serializeDiff()).toStrictEqual({
+					id: 1,
+				});
+			}
+		}
+
+		{
+			// Apply a patch without originals update.
+			{
+				const modelInstance = s.property.model(testModel).type.applyPatch(
+					testModel.model(
+						Object.assign(new TestModel(), {
+							id: 1,
+							name: "test",
+							price: 12.548777,
+						}),
+					).instance,
+					{id: 1, name: "another"},
+					false,
+				);
+
+				expect(
+					testModel.model(modelInstance).getInstanceProperties(),
+				).toStrictEqual({
+					id: 1,
+					name: "another",
+					price: 12.548777,
+				});
+				expect(testModel.model(modelInstance).serializeDiff()).toStrictEqual({
+					id: 1,
+					name: "another",
+				});
+			}
+
+			{
+				const modelInstance = s.property
+					.model(testModel)
+					.type.applyPatch(undefined, {id: 1, name: "test"}, false);
+
+				expect(
+					testModel.model(modelInstance).getInstanceProperties(),
+				).toStrictEqual({
+					id: 1,
+					name: "test",
+					price: undefined,
+				});
+				expect(testModel.model(modelInstance).serializeDiff()).toStrictEqual({
+					id: 1,
+					name: "test",
+				});
+			}
+
+			{
+				const modelInstance = s.property
+					.model(testModel)
+					.type.applyPatch(null, {id: 1, name: "test"}, false);
+
+				expect(
+					testModel.model(modelInstance).getInstanceProperties(),
+				).toStrictEqual({
+					id: 1,
+					name: "test",
+					price: undefined,
+				});
+				expect(testModel.model(modelInstance).serializeDiff()).toStrictEqual({
+					id: 1,
+					name: "test",
+				});
+			}
+		}
 	});
 });

tests/model/types/numeric.test.ts

@@ -2,58 +2,163 @@ import {describe, expect, test} from "vitest";
 import {InvalidTypeValueError, NumericType, s} from "../../../src/library";
 
 describe("numeric type", () => {
-	test("numeric type definition", () => {
+	test("definition", () => {
 		const numericType = s.property.numeric();
 		expect(numericType.type).toBeInstanceOf(NumericType);
 	});
 
-	test("numeric type functions", () => {
+	describe("serialize", () => {
+		test("serialize", () => {
 			expect(s.property.numeric().type.serialize(5.257)).toBe(5.257);
-		expect(s.property.numeric().type.deserialize(5.257)).toBe(5.257);
-		expect(s.property.numeric().type.serializeDiff(542)).toBe(542);
 
 			expect(s.property.numeric().type.serialize(null)).toBe(null);
-		expect(s.property.numeric().type.deserialize(null)).toBe(null);
-		expect(s.property.numeric().type.serializeDiff(null)).toBe(null);
-
 			expect(s.property.numeric().type.serialize(undefined)).toBe(undefined);
-		expect(s.property.numeric().type.deserialize(undefined)).toBe(undefined);
+		});
-		expect(s.property.numeric().type.serializeDiff(undefined)).toBe(undefined);
 
+		test("invalid parameters", () => {
+			expect(() => s.property.numeric().type.serialize({} as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+		});
+	});
+
+	describe("deserialize", () => {
+		test("deserialize", () => {
+			expect(s.property.numeric().type.deserialize(5.257)).toBe(5.257);
+
+			expect(s.property.numeric().type.deserialize(null)).toBe(null);
+			expect(s.property.numeric().type.deserialize(undefined)).toBe(undefined);
+		});
+
+		test("invalid parameters", () => {
+			expect(() =>
+				s.property.numeric().type.deserialize({} as any),
+			).toThrowError(InvalidTypeValueError);
+		});
+	});
+
+	describe("serializeDiff", () => {
+		test("serializeDiff", () => {
+			expect(s.property.numeric().type.serializeDiff(542)).toBe(542);
+
+			expect(s.property.numeric().type.serializeDiff(null)).toBe(null);
+			expect(s.property.numeric().type.serializeDiff(undefined)).toBe(
+				undefined,
+			);
+		});
+
+		test("invalid parameters", () => {
+			expect(() =>
+				s.property.numeric().type.serializeDiff({} as any),
+			).toThrowError(InvalidTypeValueError);
+		});
+	});
+
+	describe("hasChanged", () => {
+		test("hasChanged", () => {
 			expect(s.property.numeric().type.hasChanged(5.257, 5.257)).toBeFalsy();
 			expect(s.property.numeric().type.hasChanged(null, null)).toBeFalsy();
-		expect(s.property.numeric().type.hasChanged(undefined, undefined)).toBeFalsy();
+			expect(
-		expect(s.property.numeric().type.hasChanged(null, undefined)).toBeTruthy();
+				s.property.numeric().type.hasChanged(undefined, undefined),
-		expect(s.property.numeric().type.hasChanged(undefined, null)).toBeTruthy();
+			).toBeFalsy();
+			expect(
+				s.property.numeric().type.hasChanged(null, undefined),
+			).toBeTruthy();
+			expect(
+				s.property.numeric().type.hasChanged(undefined, null),
+			).toBeTruthy();
 			expect(s.property.numeric().type.hasChanged(null, 5.257)).toBeTruthy();
-		expect(s.property.numeric().type.hasChanged(undefined, 5.257)).toBeTruthy();
+			expect(
+				s.property.numeric().type.hasChanged(undefined, 5.257),
+			).toBeTruthy();
 			expect(s.property.numeric().type.hasChanged(5.257, null)).toBeTruthy();
-		expect(s.property.numeric().type.hasChanged(5.257, undefined)).toBeTruthy();
+			expect(
+				s.property.numeric().type.hasChanged(5.257, undefined),
+			).toBeTruthy();
+		});
 
-		expect(s.property.numeric().type.serializedHasChanged(5.257, 5.257)).toBeFalsy();
+		test("invalid parameters", () => {
-		expect(s.property.numeric().type.serializedHasChanged(null, null)).toBeFalsy();
+			expect(
-		expect(s.property.numeric().type.serializedHasChanged(undefined, undefined)).toBeFalsy();
+				s.property.numeric().type.hasChanged({} as any, {} as any),
-		expect(s.property.numeric().type.serializedHasChanged(null, undefined)).toBeTruthy();
+			).toBeTruthy();
-		expect(s.property.numeric().type.serializedHasChanged(undefined, null)).toBeTruthy();
+			expect(
-		expect(s.property.numeric().type.serializedHasChanged(null, 5.257)).toBeTruthy();
+				s.property.numeric().type.hasChanged(false as any, false as any),
-		expect(s.property.numeric().type.serializedHasChanged(undefined, 5.257)).toBeTruthy();
+			).toBeFalsy();
-		expect(s.property.numeric().type.serializedHasChanged(5.257, null)).toBeTruthy();
+		});
-		expect(s.property.numeric().type.serializedHasChanged(5.257, undefined)).toBeTruthy();
+	});
 
+	describe("serializedHasChanged", () => {
+		test("serializedHasChanged", () => {
+			expect(
+				s.property.numeric().type.serializedHasChanged(5.257, 5.257),
+			).toBeFalsy();
+			expect(
+				s.property.numeric().type.serializedHasChanged(null, null),
+			).toBeFalsy();
+			expect(
+				s.property.numeric().type.serializedHasChanged(undefined, undefined),
+			).toBeFalsy();
+			expect(
+				s.property.numeric().type.serializedHasChanged(null, undefined),
+			).toBeTruthy();
+			expect(
+				s.property.numeric().type.serializedHasChanged(undefined, null),
+			).toBeTruthy();
+			expect(
+				s.property.numeric().type.serializedHasChanged(null, 5.257),
+			).toBeTruthy();
+			expect(
+				s.property.numeric().type.serializedHasChanged(undefined, 5.257),
+			).toBeTruthy();
+			expect(
+				s.property.numeric().type.serializedHasChanged(5.257, null),
+			).toBeTruthy();
+			expect(
+				s.property.numeric().type.serializedHasChanged(5.257, undefined),
+			).toBeTruthy();
+		});
+
+		test("invalid parameters", () => {
+			expect(
+				s.property.numeric().type.serializedHasChanged({} as any, {} as any),
+			).toBeTruthy();
+			expect(
+				s.property
+					.numeric()
+					.type.serializedHasChanged(false as any, false as any),
+			).toBeFalsy();
+		});
+	});
+
+	describe("resetDiff", () => {
+		test("resetDiff", () => {
 			s.property.numeric().type.resetDiff(5.257);
 			s.property.numeric().type.resetDiff(undefined);
 			s.property.numeric().type.resetDiff(null);
 		});
 
-	test("invalid parameters types", () => {
+		test("invalid parameters", () => {
-		expect(() => s.property.numeric().type.serialize({} as any)).toThrowError(InvalidTypeValueError);
+			expect(() =>
-		expect(() => s.property.numeric().type.deserialize({} as any)).toThrowError(InvalidTypeValueError)
+				s.property.numeric().type.resetDiff({} as any),
-		expect(() => s.property.numeric().type.serializeDiff({} as any)).toThrowError(InvalidTypeValueError);
+			).not.toThrow();
-		expect(() => s.property.numeric().type.resetDiff({} as any)).not.toThrow();
+		});
-		expect(s.property.numeric().type.hasChanged({} as any, {} as any)).toBeTruthy();
+	});
-		expect(s.property.numeric().type.hasChanged(false as any, false as any)).toBeFalsy();
+
-		expect(s.property.numeric().type.serializedHasChanged({} as any, {} as any)).toBeTruthy();
+	describe("clone", () => {
-		expect(s.property.numeric().type.serializedHasChanged(false as any, false as any)).toBeFalsy();
+		test("invalid parameters", () => {
 			expect(s.property.numeric().type.clone({} as any)).toStrictEqual({});
 		});
+	});
+
+	test("applyPatch", () => {
+		expect(s.property.numeric().type.applyPatch(1, 5.257, false)).toBe(5.257);
+		expect(s.property.numeric().type.applyPatch(null, 5.257, true)).toBe(5.257);
+		expect(s.property.numeric().type.applyPatch(undefined, 5.257, false)).toBe(
+			5.257,
+		);
+		expect(
+			s.property.numeric().type.applyPatch(5.257, undefined, false),
+		).toBeUndefined();
+		expect(s.property.numeric().type.applyPatch(5.257, null, false)).toBeNull();
+	});
 });

tests/model/types/object.test.ts

@@ -1,8 +1,14 @@
 import {describe, expect, test} from "vitest";
-import {InvalidTypeValueError, NumericType, ObjectType, s, StringType} from "../../../src/library";
+import {
+	InvalidTypeValueError,
+	NumericType,
+	ObjectType,
+	s,
+	StringType,
+} from "../../../src/library";
 
 describe("object type", () => {
-	test("object type definition", () => {
+	test("definition", () => {
 		const objectType = s.property.object({
 			test: s.property.string(),
 			another: s.property.numeric(),
@@ -10,10 +16,12 @@ describe("object type", () => {
 		expect(objectType.type).toBeInstanceOf(ObjectType);
 
 		expect((objectType.type as any).properties).toHaveLength(2);
-		for (const property of (objectType.type as any).properties)
+		for (const property of (objectType.type as any).properties) {
-		{ // Check all object properties.
+			// Check all object properties.
-			if (property.name == "test") expect(property.definition.type).toBeInstanceOf(StringType);
+			if (property.name == "test")
-			else if (property.name == "another") expect(property.definition.type).toBeInstanceOf(NumericType);
+				expect(property.definition.type).toBeInstanceOf(StringType);
+			else if (property.name == "another")
+				expect(property.definition.type).toBeInstanceOf(NumericType);
 			else expect.unreachable();
 		}
 	});
@@ -23,54 +31,206 @@ describe("object type", () => {
 		another: s.property.decimal(),
 	});
 
-	test("object type functions", () => {
+	describe("serialize", () => {
-		expect(testProperty.type.serialize({ test: "test", another: 12.548777 })).toEqual({ test: "test", another: "12.548777" });
+		test("serialize", () => {
-		expect(testProperty.type.deserialize({ test: "test", another: "12.548777" })).toEqual({ test: "test", another: 12.548777 });
+			expect(
-		expect(testProperty.type.serializeDiff({ test: "test", another: 12.548777 })).toEqual({ test: "test", another: "12.548777" });
+				testProperty.type.serialize({test: "test", another: 12.548777}),
+			).toEqual({test: "test", another: "12.548777"});
 
 			expect(testProperty.type.serialize(null)).toEqual(null);
-		expect(testProperty.type.deserialize(null)).toEqual(null);
-		expect(testProperty.type.serializeDiff(null)).toEqual(null);
-
 			expect(testProperty.type.serialize(undefined)).toEqual(undefined);
-		expect(testProperty.type.deserialize(undefined)).toEqual(undefined);
+		});
-		expect(testProperty.type.serializeDiff(undefined)).toEqual(undefined);
 
-		expect(testProperty.type.hasChanged({ test: "test", another: 12.548777 }, { another: 12.548777, test: "test" })).toBeFalsy();
+		test("invalid parameters", () => {
-		expect(testProperty.type.hasChanged({ test: "test", another: 12.548777 }, { test: "test", another: 12.548778 })).toBeTruthy();
+			expect(() => testProperty.type.serialize(5 as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+			expect(() => testProperty.type.serialize([] as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+		});
+	});
+
+	describe("deserialize", () => {
+		test("deserialize", () => {
+			expect(
+				testProperty.type.deserialize({test: "test", another: "12.548777"}),
+			).toEqual({test: "test", another: 12.548777});
+
+			expect(testProperty.type.deserialize(null)).toEqual(null);
+			expect(testProperty.type.deserialize(undefined)).toEqual(undefined);
+		});
+
+		test("invalid parameters", () => {
+			expect(() => testProperty.type.deserialize(5 as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+			expect(() => testProperty.type.deserialize([] as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+		});
+	});
+
+	describe("serializeDiff", () => {
+		test("serializeDiff", () => {
+			expect(
+				testProperty.type.serializeDiff({test: "test", another: 12.548777}),
+			).toEqual({test: "test", another: "12.548777"});
+
+			expect(testProperty.type.serializeDiff(null)).toEqual(null);
+			expect(testProperty.type.serializeDiff(undefined)).toEqual(undefined);
+		});
+
+		test("invalid parameters", () => {
+			expect(() => testProperty.type.serializeDiff(5 as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+			expect(() => testProperty.type.serializeDiff([] as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+		});
+	});
+
+	describe("hasChanged", () => {
+		test("hasChanged", () => {
+			expect(
+				testProperty.type.hasChanged(
+					{test: "test", another: 12.548777},
+					{another: 12.548777, test: "test"},
+				),
+			).toBeFalsy();
+			expect(
+				testProperty.type.hasChanged(
+					{test: "test", another: 12.548777},
+					{test: "test", another: 12.548778},
+				),
+			).toBeTruthy();
 			expect(testProperty.type.hasChanged(null, null)).toBeFalsy();
 			expect(testProperty.type.hasChanged(undefined, undefined)).toBeFalsy();
 			expect(testProperty.type.hasChanged(null, undefined)).toBeTruthy();
 			expect(testProperty.type.hasChanged(undefined, null)).toBeTruthy();
-		expect(testProperty.type.hasChanged(null, { test: "test", another: 12.548777 })).toBeTruthy();
+			expect(
-		expect(testProperty.type.hasChanged(undefined, { test: "test", another: 12.548777 })).toBeTruthy();
+				testProperty.type.hasChanged(null, {test: "test", another: 12.548777}),
-		expect(testProperty.type.hasChanged({ test: "test", another: 12.548777 }, null)).toBeTruthy();
+			).toBeTruthy();
-		expect(testProperty.type.hasChanged({ test: "test", another: 12.548777 }, undefined)).toBeTruthy();
+			expect(
+				testProperty.type.hasChanged(undefined, {
+					test: "test",
+					another: 12.548777,
+				}),
+			).toBeTruthy();
+			expect(
+				testProperty.type.hasChanged({test: "test", another: 12.548777}, null),
+			).toBeTruthy();
+			expect(
+				testProperty.type.hasChanged(
+					{test: "test", another: 12.548777},
+					undefined,
+				),
+			).toBeTruthy();
+		});
 
-		expect(testProperty.type.serializedHasChanged({ test: "test", another: "12.548777" }, { another: "12.548777", test: "test" })).toBeFalsy();
+		test("invalid parameters", () => {
-		expect(testProperty.type.serializedHasChanged({ test: "test", another: "12.548777" }, { test: "test", another: "12.548778" })).toBeTruthy();
+			expect(() =>
+				testProperty.type.hasChanged(5 as any, 5 as any),
+			).toThrowError(InvalidTypeValueError);
+			expect(() =>
+				testProperty.type.hasChanged({} as any, [] as any),
+			).toThrowError(InvalidTypeValueError);
+		});
+	});
+
+	describe("serializedHasChanged", () => {
+		test("serializedHasChanged", () => {
+			expect(
+				testProperty.type.serializedHasChanged(
+					{test: "test", another: "12.548777"},
+					{another: "12.548777", test: "test"},
+				),
+			).toBeFalsy();
+			expect(
+				testProperty.type.serializedHasChanged(
+					{test: "test", another: "12.548777"},
+					{test: "test", another: "12.548778"},
+				),
+			).toBeTruthy();
 			expect(testProperty.type.serializedHasChanged(null, null)).toBeFalsy();
-		expect(testProperty.type.serializedHasChanged(undefined, undefined)).toBeFalsy();
+			expect(
-		expect(testProperty.type.serializedHasChanged(null, undefined)).toBeTruthy();
+				testProperty.type.serializedHasChanged(undefined, undefined),
-		expect(testProperty.type.serializedHasChanged(undefined, null)).toBeTruthy();
+			).toBeFalsy();
-		expect(testProperty.type.serializedHasChanged(null, { test: "test", another: "12.548777" })).toBeTruthy();
+			expect(
-		expect(testProperty.type.serializedHasChanged(undefined, { test: "test", another: "12.548777" })).toBeTruthy();
+				testProperty.type.serializedHasChanged(null, undefined),
-		expect(testProperty.type.serializedHasChanged({ test: "test", another: "12.548777" }, null)).toBeTruthy();
+			).toBeTruthy();
-		expect(testProperty.type.serializedHasChanged({ test: "test", another: "12.548777" }, undefined)).toBeTruthy();
+			expect(
+				testProperty.type.serializedHasChanged(undefined, null),
+			).toBeTruthy();
+			expect(
+				testProperty.type.serializedHasChanged(null, {
+					test: "test",
+					another: "12.548777",
+				}),
+			).toBeTruthy();
+			expect(
+				testProperty.type.serializedHasChanged(undefined, {
+					test: "test",
+					another: "12.548777",
+				}),
+			).toBeTruthy();
+			expect(
+				testProperty.type.serializedHasChanged(
+					{test: "test", another: "12.548777"},
+					null,
+				),
+			).toBeTruthy();
+			expect(
+				testProperty.type.serializedHasChanged(
+					{test: "test", another: "12.548777"},
+					undefined,
+				),
+			).toBeTruthy();
+		});
 
-		testProperty.type.resetDiff({ test: "test", another: 12.548777 });
+		test("invalid parameters", () => {
+			expect(() =>
+				testProperty.type.serializedHasChanged(5 as any, 5 as any),
+			).toThrowError(InvalidTypeValueError);
+			expect(() =>
+				testProperty.type.serializedHasChanged({} as any, [] as any),
+			).toThrowError(InvalidTypeValueError);
+		});
+	});
+
+	describe("resetDiff", () => {
+		test("resetDiff", () => {
+			testProperty.type.resetDiff({test: "test", another: 12.548777});
 			testProperty.type.resetDiff(undefined);
 			testProperty.type.resetDiff(null);
+		});
 
-		{ // Test that values are cloned in a different object.
+		test("invalid parameters", () => {
-			const propertyValue = { test: "test", another: 12.548777 };
+			expect(() => testProperty.type.resetDiff(5 as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+			expect(() => testProperty.type.resetDiff([] as any)).toThrowError(
+				InvalidTypeValueError,
+			);
+		});
+	});
+
+	describe("clone", () => {
+		test("clone", () => {
+			{
+				// Test that values are cloned in a different object.
+				const propertyValue = {test: "test", another: 12.548777};
 				const clonedPropertyValue = testProperty.type.clone(propertyValue);
 				expect(clonedPropertyValue).not.toBe(propertyValue);
 				expect(clonedPropertyValue).toEqual(propertyValue);
 			}
-		{ // Test that values are cloned in a different object.
+			{
-			const propertyValue = { arr: [12, 11] };
+				// Test that values are cloned in a different object.
-			const clonedPropertyValue = s.property.object({ arr: s.property.array(s.property.numeric()) }).type.clone(propertyValue);
+				const propertyValue = {arr: [12, 11]};
+				const clonedPropertyValue = s.property
+					.object({arr: s.property.array(s.property.numeric())})
+					.type.clone(propertyValue);
 				expect(clonedPropertyValue).not.toBe(propertyValue);
 				expect(clonedPropertyValue).toEqual(propertyValue);
 				expect(clonedPropertyValue.arr).not.toBe(propertyValue.arr);
@@ -80,21 +240,84 @@ describe("object type", () => {
 			expect(testProperty.type.clone(null)).toBe(null);
 		});
 
-	test("invalid parameters types", () => {
+		test("invalid parameters", () => {
-		expect(() => testProperty.type.serialize(5 as any)).toThrowError(InvalidTypeValueError);
+			expect(() => testProperty.type.clone(5 as any)).toThrowError(
-		expect(() => testProperty.type.deserialize(5 as any)).toThrowError(InvalidTypeValueError);
+				InvalidTypeValueError,
-		expect(() => testProperty.type.serializeDiff(5 as any)).toThrowError(InvalidTypeValueError);
+			);
-		expect(() => testProperty.type.resetDiff(5 as any)).toThrowError(InvalidTypeValueError);
+			expect(() => testProperty.type.clone([] as any)).toThrowError(
-		expect(() => testProperty.type.hasChanged(5 as any, 5 as any)).toThrowError(InvalidTypeValueError);
+				InvalidTypeValueError,
-		expect(() => testProperty.type.serializedHasChanged(5 as any, 5 as any)).toThrowError(InvalidTypeValueError);
+			);
-		expect(() => testProperty.type.clone(5 as any)).toThrowError(InvalidTypeValueError);
+		});
+	});
 
-		expect(() => testProperty.type.serialize([] as any)).toThrowError(InvalidTypeValueError);
+	test("applyPatch", () => {
-		expect(() => testProperty.type.deserialize([] as any)).toThrowError(InvalidTypeValueError);
+		{
-		expect(() => testProperty.type.serializeDiff([] as any)).toThrowError(InvalidTypeValueError);
+			// Apply a patch with undefined / NULL values.
-		expect(() => testProperty.type.resetDiff([] as any)).toThrowError(InvalidTypeValueError);
+			expect(
-		expect(() => testProperty.type.hasChanged({} as any, [] as any)).toThrowError(InvalidTypeValueError);
+				testProperty.type.applyPatch(
-		expect(() => testProperty.type.serializedHasChanged({} as any, [] as any)).toThrowError(InvalidTypeValueError);
+					{test: "test", another: 12.548777},
-		expect(() => testProperty.type.clone([] as any)).toThrowError(InvalidTypeValueError);
+					undefined,
+					false,
+				),
+			).toBeUndefined();
+			expect(
+				testProperty.type.applyPatch(
+					{test: "test", another: 12.548777},
+					null,
+					true,
+				),
+			).toBeNull();
+		}
+
+		{
+			// Invalid patch.
+			expect(() =>
+				testProperty.type.applyPatch(
+					{test: "test", another: 12.548777},
+					5416 as any,
+					false,
+				),
+			).toThrow(InvalidTypeValueError);
+		}
+
+		{
+			// Apply a patch.
+			{
+				const objectInstance = testProperty.type.applyPatch(
+					{test: "test", another: 12.548777},
+					{test: "another"},
+					true,
+				);
+
+				expect(objectInstance).toStrictEqual({
+					test: "another",
+					another: 12.548777,
+				});
+			}
+
+			{
+				const objectInstance = testProperty.type.applyPatch(
+					undefined,
+					{test: "test"},
+					false,
+				);
+
+				expect(objectInstance).toStrictEqual({
+					test: "test",
+				});
+			}
+
+			{
+				const objectInstance = testProperty.type.applyPatch(
+					null,
+					{test: "test"},
+					false,
+				);
+
+				expect(objectInstance).toStrictEqual({
+					test: "test",
+				});
+			}
+		}
 	});
 });

tests/model/types/string.test.ts

@@ -2,62 +2,161 @@ import {describe, expect, test} from "vitest";
 import {s, StringType} from "../../../src/library";
 
 describe("string type", () => {
-	test("string type definition", () => {
+	test("definition", () => {
 		const stringType = s.property.string();
 		expect(stringType.type).toBeInstanceOf(StringType);
 	});
 
-	test("string type functions", () => {
+	describe("serialize", () => {
+		test("serialize", () => {
 			expect(s.property.string().type.serialize("test")).toBe("test");
-		expect(s.property.string().type.deserialize("test")).toBe("test");
-		expect(s.property.string().type.serializeDiff("test")).toBe("test");
-
 			expect(s.property.string().type.serialize(null)).toBe(null);
-		expect(s.property.string().type.deserialize(null)).toBe(null);
-		expect(s.property.string().type.serializeDiff(null)).toBe(null);
-
 			expect(s.property.string().type.serialize(undefined)).toBe(undefined);
-		expect(s.property.string().type.deserialize(undefined)).toBe(undefined);
+		});
-		expect(s.property.string().type.serializeDiff(undefined)).toBe(undefined);
 
+		test("invalid parameters", () => {
+			const testDate = new Date();
+			expect(s.property.string().type.serialize({} as any)).toBe(
+				"[object Object]",
+			);
+			expect(s.property.string().type.serialize(2120 as any)).toBe("2120");
+			expect(s.property.string().type.serialize(testDate as any)).toBe(
+				testDate.toString(),
+			);
+		});
+	});
+
+	describe("deserialize", () => {
+		test("deserialize", () => {
+			expect(s.property.string().type.deserialize("test")).toBe("test");
+			expect(s.property.string().type.deserialize(null)).toBe(null);
+			expect(s.property.string().type.deserialize(undefined)).toBe(undefined);
+		});
+
+		test("invalid parameters", () => {
+			expect(s.property.string().type.deserialize({} as any)).toBe(
+				"[object Object]",
+			);
+			expect(s.property.string().type.deserialize(2120 as any)).toBe("2120");
+		});
+	});
+
+	describe("serializeDiff", () => {
+		test("serializeDiff", () => {
+			expect(s.property.string().type.serializeDiff("test")).toBe("test");
+			expect(s.property.string().type.serializeDiff(null)).toBe(null);
+			expect(s.property.string().type.serializeDiff(undefined)).toBe(undefined);
+		});
+
+		test("invalid parameters", () => {
+			expect(s.property.string().type.serializeDiff({} as any)).toBe(
+				"[object Object]",
+			);
+			expect(s.property.string().type.serializeDiff(2120 as any)).toBe("2120");
+		});
+	});
+
+	describe("hasChanged", () => {
+		test("hasChanged", () => {
 			expect(s.property.string().type.hasChanged("test", "test")).toBeFalsy();
 			expect(s.property.string().type.hasChanged(null, null)).toBeFalsy();
-		expect(s.property.string().type.hasChanged(undefined, undefined)).toBeFalsy();
+			expect(
+				s.property.string().type.hasChanged(undefined, undefined),
+			).toBeFalsy();
 			expect(s.property.string().type.hasChanged(null, undefined)).toBeTruthy();
 			expect(s.property.string().type.hasChanged(undefined, null)).toBeTruthy();
 			expect(s.property.string().type.hasChanged(null, "test")).toBeTruthy();
-		expect(s.property.string().type.hasChanged(undefined, "test")).toBeTruthy();
+			expect(
+				s.property.string().type.hasChanged(undefined, "test"),
+			).toBeTruthy();
 			expect(s.property.string().type.hasChanged("test", null)).toBeTruthy();
-		expect(s.property.string().type.hasChanged("test", undefined)).toBeTruthy();
+			expect(
+				s.property.string().type.hasChanged("test", undefined),
+			).toBeTruthy();
+		});
 
-		expect(s.property.string().type.serializedHasChanged("test", "test")).toBeFalsy();
+		test("invalid parameters", () => {
-		expect(s.property.string().type.serializedHasChanged(null, null)).toBeFalsy();
+			expect(
-		expect(s.property.string().type.serializedHasChanged(undefined, undefined)).toBeFalsy();
+				s.property.string().type.hasChanged({} as any, {} as any),
-		expect(s.property.string().type.serializedHasChanged(null, undefined)).toBeTruthy();
+			).toBeTruthy();
-		expect(s.property.string().type.serializedHasChanged(undefined, null)).toBeTruthy();
+			expect(
-		expect(s.property.string().type.serializedHasChanged(null, "test")).toBeTruthy();
+				s.property.string().type.hasChanged(false as any, false as any),
-		expect(s.property.string().type.serializedHasChanged(undefined, "test")).toBeTruthy();
+			).toBeFalsy();
-		expect(s.property.string().type.serializedHasChanged("test", null)).toBeTruthy();
+		});
-		expect(s.property.string().type.serializedHasChanged("test", undefined)).toBeTruthy();
+	});
 
+	describe("serializedHasChanged", () => {
+		test("serializedHasChanged", () => {
+			expect(
+				s.property.string().type.serializedHasChanged("test", "test"),
+			).toBeFalsy();
+			expect(
+				s.property.string().type.serializedHasChanged(null, null),
+			).toBeFalsy();
+			expect(
+				s.property.string().type.serializedHasChanged(undefined, undefined),
+			).toBeFalsy();
+			expect(
+				s.property.string().type.serializedHasChanged(null, undefined),
+			).toBeTruthy();
+			expect(
+				s.property.string().type.serializedHasChanged(undefined, null),
+			).toBeTruthy();
+			expect(
+				s.property.string().type.serializedHasChanged(null, "test"),
+			).toBeTruthy();
+			expect(
+				s.property.string().type.serializedHasChanged(undefined, "test"),
+			).toBeTruthy();
+			expect(
+				s.property.string().type.serializedHasChanged("test", null),
+			).toBeTruthy();
+			expect(
+				s.property.string().type.serializedHasChanged("test", undefined),
+			).toBeTruthy();
+		});
+
+		test("invalid parameters", () => {
+			expect(
+				s.property.string().type.serializedHasChanged({} as any, {} as any),
+			).toBeTruthy();
+			expect(
+				s.property
+					.string()
+					.type.serializedHasChanged(false as any, false as any),
+			).toBeFalsy();
+		});
+	});
+
+	describe("resetDiff", () => {
+		test("resetDiff", () => {
 			s.property.string().type.resetDiff("test");
 			s.property.string().type.resetDiff(undefined);
 			s.property.string().type.resetDiff(null);
 		});
 
-	test("invalid parameters types", () => {
+		test("invalid parameters", () => {
-		const testDate = new Date();
+			expect(() => s.property.string().type.resetDiff({} as any)).not.toThrow();
-		expect(s.property.string().type.serialize({} as any)).toBe("[object Object]");
+		});
-		expect(s.property.string().type.serialize(2120 as any)).toBe("2120");
+	});
-		expect(s.property.string().type.serialize(testDate as any)).toBe(testDate.toString());
+
-		expect(s.property.string().type.deserialize({} as any)).toBe("[object Object]");
+	test("clone", () => {
-		expect(s.property.string().type.deserialize(2120 as any)).toBe("2120");
-		expect(s.property.string().type.serializeDiff({} as any)).toBe("[object Object]");
-		expect(s.property.string().type.serializeDiff(2120 as any)).toBe("2120");
-		expect(s.property.string().type.hasChanged({} as any, {} as any)).toBeTruthy();
-		expect(s.property.string().type.hasChanged(false as any, false as any)).toBeFalsy();
-		expect(s.property.string().type.serializedHasChanged({} as any, {} as any)).toBeTruthy();
-		expect(s.property.string().type.serializedHasChanged(false as any, false as any)).toBeFalsy();
 		expect(s.property.string().type.clone({} as any)).toStrictEqual({});
 	});
+
+	test("applyPatch", () => {
+		expect(s.property.string().type.applyPatch("another", "test", false)).toBe(
+			"test",
+		);
+		expect(s.property.string().type.applyPatch(undefined, "test", true)).toBe(
+			"test",
+		);
+		expect(s.property.string().type.applyPatch(null, "test", false)).toBe(
+			"test",
+		);
+		expect(
+			s.property.string().type.applyPatch("test", undefined, false),
+		).toBeUndefined();
+		expect(s.property.string().type.applyPatch("test", null, false)).toBeNull();
+	});
 });

tsconfig.json

@@ -2,7 +2,7 @@
 	"ts-node": {
 		"compilerOptions": {
 			"module": "ESNext",
-	    "types": ["node"],
+			"types": ["node"]
 		}
 	},
 
@@ -22,9 +22,6 @@
 		"module": "ES6",
 		"target": "ES6",
 		"moduleResolution": "Bundler",
-    "lib": [
+		"lib": ["ESNext", "DOM"]
-      "ESNext",
-      "DOM"
-    ]
 	}
 }

vite.config.ts

@@ -1,10 +1,10 @@
-import {ConfigEnv, defineConfig, UserConfig} from "vite";
+import {defineConfig, UserConfig} from "vite";
 import dts from "vite-plugin-dts";
 
 // https://vitejs.dev/config/
 
-export default defineConfig(({ mode }: ConfigEnv): UserConfig => {
+export default defineConfig((): UserConfig => {
-	return ({
+	return {
 		build: {
 			outDir: "lib",
 			sourcemap: true,
@@ -22,6 +22,6 @@ export default defineConfig(({ mode }: ConfigEnv): UserConfig => {
 				rollupTypes: true,
 				exclude: ["node_modules"],
 			}),
-		]
+		],
-	});
+	};
 });