spaghiajoeojo / express-beans

import { flushPromises } from '@test/utils/testUtils';

import { InjectBean } from '@/core/decorators/InjectBean';

jest.mock('@/core', () => ({

  logger: {

    info: jest.fn(),

    debug: jest.fn(),

    error: jest.fn(),

  },

}));

describe('InjectBean.ts', () => {

  beforeEach(() => {

    jest.resetAllMocks();

  });

  it('injects a dependency', async () => {

    // GIVEN

    class TypeA {}

    const T: any = TypeA;

    T.instance = new TypeA();

    // WHEN

    class Class {

      @InjectBean(TypeA)

      private dep!: TypeA;

      getDep() {

        return this.dep;

      }

    }

    const instance = new Class();

    await flushPromises();

    // THEN

    expect(instance.getDep()).toBe(T.instance);

  });

  it('injects multiple dependencies', async () => {

    // GIVEN

    class TypeA {}

    const TA: any = TypeA;

    TA.instance = new TypeA();

    class TypeB {}

    const TB: any = TypeB;

    TB.instance = new TypeB();

    // WHEN

    class Class {

      @InjectBean(TypeA)

        dep1!: TypeA;

      @InjectBean(TypeB)

        dep2!: TypeB;

      getDeps() {

        return [this.dep1, this.dep2];

      }

    }

    const instance = new Class();

    await flushPromises();

    // THEN

    const [dep1, dep2] = instance.getDeps();

    expect(dep1).toBe(TA.instance);

    expect(dep2).toBe(TB.instance);

  });

  it('throws an error if trying to inject a non injectable dependency', async () => {

    // GIVEN

    class TypeA {}

    let instance;

    // WHEN

    expect(() => {

      class Class {

        @InjectBean(TypeA)

          dep!: TypeA;

      }

      instance = new Class();

    }).toThrow(new Error('Cannot get instance from TypeA. Make sure that TypeA has @Bean as class decorator'));

    expect(instance).toBe(undefined);

  });

  it('throws an error if trying to inject without specify a type', async () => {

    // GIVEN

    class TypeA {}

    let instance;

    // WHEN

    expect(() => {

      class Class {

        @InjectBean(null)

          dep!: TypeA;

      }

      instance = new Class();

    }).toThrow(new Error('Please specify the type of Bean. Example: @InjectBean(BeanClass)'));

    expect(instance).toBe(undefined);

  });

  it('throws an error when dependency is not found', async () => {

    // GIVEN

    class TypeA {}

    class Class {

      @InjectBean(TypeA)

        dep!: TypeA;

      getDep() {

        return this.dep;

      }

    }

    // WHEN

    let dep;

    expect(() => {

      const instance = new Class();

      dep = instance.getDep();

    }).toThrow(new Error('Cannot get instance from TypeA. Make sure that TypeA has @Bean as class decorator'));

    // THEN

    expect(dep).toBe(undefined);

  });

});