feat(repository): change Model.modelName to a computed property

Implement `modelName` getter that returns model's `definition.name`
or model class name if no definition was provided.

Author: bajtos

packages/repository/src/model.ts

@@ -167,7 +167,10 @@ function asObject(value: any, options?: Options): any {
  * Base class for models
  */
 export abstract class Model {
-  static modelName: string;
+  static get modelName(): string {
+    return (this.definition && this.definition.name) || this.name;
+  }
+
   static definition: ModelDefinition;
 
   /**

packages/repository/test/unit/decorator/model-and-relation.decorator.unit.ts

@@ -164,6 +164,12 @@ describe('model decorator', () => {
     expect(meta).to.eql({name: 'foo'});
   });
 
+  it('updates static property "modelName"', () => {
+    @model()
+    class Category extends Entity {}
+    expect(Category.modelName).to.equal('Category');
+  });
+
   it('adds model metadata with arbitrary properties', () => {
     @model({arbitrary: 'property'})
     class Arbitrary {

packages/repository/test/unit/model/model.unit.ts

@@ -293,4 +293,13 @@ describe('model', () => {
     const instance = new NoId();
     expect(() => instance.getId()).to.throw(/missing.*id/);
   });
+
+  it('reads model name from the definition', () => {
+    expect(Customer.modelName).to.equal('Customer');
+  });
+
+  it('reads model name from the class name', () => {
+    class MyModel extends Entity {}
+    expect(MyModel.modelName).to.equal('MyModel');
+  });
 });