Create mock with asserts and stub methods

Author: rsaladocid

tests/Contexts/Mooc/Courses/__mocks__/CourseRepositoryMock.ts

@@ -0,0 +1,29 @@
+import { CourseRepository } from '../../../../../src/Contexts/Mooc/Courses/domain/CourseRepository';
+import { Course } from '../../../../../src/Contexts/Mooc/Courses/domain/Course';
+import { CourseId } from '../../../../../src/Contexts/Mooc/Shared/domain/Courses/CourseId';
+import { Nullable } from '../../../../../src/Contexts/Shared/domain/Nullable';
+
+export class CourseRepositoryMock implements CourseRepository {
+  private mockSave = jest.fn();
+  private mockSearch = jest.fn();
+
+  async save(course: Course): Promise<void> {
+    this.mockSave(course);
+  }
+
+  assertLastSavedCourseIs(expected: Course): void {
+    expect(this.mockSave).toHaveBeenCalledWith(expected);
+  }
+
+  async search(id: CourseId): Promise<Nullable<Course>> {
+    return this.mockSearch(id);
+  }
+
+  whenSearchThenReturn(value: Nullable<Course>): void {
+    this.mockSearch.mockReturnValue(value);
+  }
+
+  assertLastSearchedCourseIs(expected: CourseId): void {
+    expect(this.mockSearch).toHaveBeenCalledWith(expected);
+  }
+}

tests/Contexts/Mooc/Courses/application/CourseCreator.test.ts

@@ -1,19 +1,16 @@
 import { CourseCreator } from '../../../../../src/Contexts/Mooc/Courses/application/CourseCreator';
+import { EventBus } from '../../../../../src/Contexts/Shared/domain/EventBus';
 import { CourseMother } from '../domain/CourseMother';
+import { CourseRepositoryMock } from '../__mocks__/CourseRepositoryMock';
 import { CreateCourseRequestMother } from './CreateCourseRequestMother';
-import { CourseRepository } from '../../../../../src/Contexts/Mooc/Courses/domain/CourseRepository';
-import { Course } from '../../../../../src/Contexts/Mooc/Courses/domain/Course';
-import { EventBus } from '../../../../../src/Contexts/Shared/domain/EventBus';
 
-let repository: CourseRepository;
+let repository: CourseRepositoryMock;
 let creator: CourseCreator;
 
-const createRepository = (): CourseRepository => ({ save: jest.fn(), search: jest.fn() });
-const eventBus = (): EventBus => ({ publish: jest.fn()});
-const shouldSave = (course: Course) => expect(repository.save).toHaveBeenCalledWith(course);
+const eventBus = (): EventBus => ({ publish: jest.fn() });
 
 beforeEach(() => {
-  repository = createRepository();
+  repository = new CourseRepositoryMock();
   creator = new CourseCreator(repository, eventBus());
 });
 
@@ -24,5 +21,5 @@ it('should create a valid course', async () => {
 
   await creator.run(request);
 
-  shouldSave(course);
+  repository.assertLastSavedCourseIs(course);
 });