Add models extension system.

README.md

@@ -19,7 +19,7 @@
 </p>
 
 <p align="center">
-	<img alt="Version 3.0.2" src="https://img.shields.io/badge/version-3.0.2-blue" />
+	<img alt="Version 3.1.0" src="https://img.shields.io/badge/version-3.1.0-blue" />
 </p>
 
 ## Introduction

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@sharkitek/core",
-	"version": "3.0.2",
+	"version": "3.1.0",
 	"description": "TypeScript library for well-designed model architectures.",
 	"keywords": [
 		"deserialization",

src/Model/Model.ts

@@ -34,10 +34,20 @@ export type SerializedModel<Shape extends ModelShape> = {
  */
 export type Model<Shape extends ModelShape, IdentifierType = unknown> = ModelDefinition<Shape, IdentifierType> & PropertiesModel<Shape>;
 
+/**
+ * Type of the extends function of model classes.
+ */
+export type ExtendsFunctionType<ModelType extends Model<Shape, IdentifierType<Shape, Identifier>>, Shape extends ModelShape, Identifier extends keyof Shape = any> =
+	<Extension extends object>(extension: ThisType<ModelType> & Extension) => ModelClass<ModelType & Extension, Shape, Identifier>;
+
 /**
  * Type of a model class.
  */
-export type ModelClass<Shape extends ModelShape, Identifier extends keyof Shape = any> = ConstructorOf<Model<Shape, IdentifierType<Shape, Identifier>>>;
+export type ModelClass<ModelType extends Model<Shape, IdentifierType<Shape, Identifier>>, Shape extends ModelShape, Identifier extends keyof Shape = any> = (
+	ConstructorOf<ModelType> & {
+		extends: ExtendsFunctionType<ModelType, Shape, Identifier>;
+	}
+);
 
 /**
  * Identifier type.
@@ -96,12 +106,14 @@ export interface ModelDefinition<Shape extends ModelShape, IdentifierType, Model
 export function model<ModelType extends Model<Shape, IdentifierType<Shape, Identifier>>, Shape extends ModelShape, Identifier extends keyof Shape = any>(
 	shape: Shape,
 	identifier?: Identifier,
-): ConstructorOf<ModelType>
+): ModelClass<ModelType, Shape, Identifier>
 {
 	// Get shape entries.
 	const shapeEntries = Object.entries(shape) as [keyof Shape, UnknownDefinition][];
 
-	return class GenericModel implements ModelDefinition<Shape, IdentifierType<Shape, Identifier>, ModelType>
+	return withExtends(
+		// Initialize generic model class.
+		class GenericModel implements ModelDefinition<Shape, IdentifierType<Shape, Identifier>, ModelType>
 		{
 			constructor()
 			{
@@ -232,5 +244,38 @@ export function model<ModelType extends Model<Shape, IdentifierType<Shape, Ident
 				return diff; // Return the difference.
 			}
 
-	} as unknown as ConstructorOf<ModelType>;
+		} as unknown as ConstructorOf<ModelType>
+	);
+}
+
+/**
+ * Any Sharkitek model.
+ */
+export type AnyModel = Model<any, any>;
+/**
+ * Any Sharkitek model class.
+ */
+export type AnyModelClass = ModelClass<AnyModel, any>;
+
+/**
+ * Add extends function to a model class.
+ * @param genericModel The model class on which to add the extends function.
+ */
+function withExtends<ModelType extends Model<Shape, IdentifierType<Shape, Identifier>>, Shape extends ModelShape, Identifier extends keyof Shape = any>(
+	genericModel: ConstructorOf<ModelType>
+): ModelClass<ModelType, Shape, Identifier>
+{
+	return Object.assign(
+		genericModel,
+		{ // Extends function definition.
+			extends<Extension extends object>(extension: Extension): ModelClass<ModelType & Extension, Shape, Identifier>
+			{
+				// Clone the model class and add extends function.
+				const classClone = withExtends(class extends (genericModel as AnyModelClass) {} as AnyModelClass as ConstructorOf<ModelType & Extension>);
+				// Add extension to the model class prototype.
+				Object.assign(classClone.prototype, extension);
+				return classClone;
+			}
+		}
+	) as AnyModelClass as ModelClass<ModelType, Shape, Identifier>;
 }

tests/Model.test.ts

@@ -9,6 +9,11 @@ class Author extends s.model({
 	email: s.property.string(),
 	createdAt: s.property.date(),
 	active: s.property.bool(),
+}).extends({
+	extension(): string
+	{
+		return this.name;
+	}
 })
 {
 	active: boolean = true;
@@ -157,3 +162,9 @@ it("save with modified submodels", () => {
 		],
 	});
 });
+
+it("test author extension", () => {
+	const author = new Author();
+	author.name = "test name";
+	expect(author.extension()).toStrictEqual("test name");
+});

tsconfig.json

@@ -11,6 +11,7 @@
 	  "incremental": true,
 	  "sourceMap": true,
     "noImplicitAny": true,
+	  "noImplicitThis": true,
 	  "esModuleInterop": true,
 	  "allowSyntheticDefaultImports": true,
 	  "resolveJsonModule": true,
@@ -24,6 +25,6 @@
     "lib": [
       "ESNext",
       "DOM"
-    ],
+    ]
   }
 }