test(sample-14): added unit test and other improvements

sample/14-mongoose-base/README.md

@@ -1,4 +1,4 @@
-### Mongoose base sample
+## Mongoose base sample
 
 ### Installation
 

sample/14-mongoose-base/package.json

@@ -32,20 +32,38 @@
     "@nestjs/schematics": "8.0.4",
     "@nestjs/testing": "8.1.2",
     "@types/express": "4.17.13",
+    "@types/jest": "27.0.2",
     "@types/node": "16.11.6",
     "@types/supertest": "2.0.11",
+    "@typescript-eslint/eslint-plugin": "4.33.0",
+    "@typescript-eslint/parser": "4.33.0",
+    "eslint": "7.32.0",
+    "eslint-config-prettier": "8.3.0",
+    "eslint-plugin-import": "2.25.2",
     "jest": "27.3.1",
     "prettier": "2.4.1",
     "supertest": "6.1.6",
     "ts-jest": "27.0.7",
     "ts-loader": "9.2.6",
     "ts-node": "10.4.0",
     "tsconfig-paths": "3.11.0",
-    "@typescript-eslint/eslint-plugin": "4.33.0",
-    "@typescript-eslint/parser": "4.33.0",
-    "eslint": "7.32.0",
-    "eslint-config-prettier": "8.3.0",
-    "eslint-plugin-import": "2.25.2",
     "typescript": "4.3.5"
+  },
+  "jest": {
+    "moduleFileExtensions": [
+      "js",
+      "json",
+      "ts"
+    ],
+    "rootDir": "src",
+    "testRegex": ".spec.ts$",
+    "transform": {
+      "^.+\\.(t|j)s$": "ts-jest"
+    },
+    "collectCoverageFrom": [
+      "**/*.(t|j)s"
+    ],
+    "coverageDirectory": "../coverage",
+    "testEnvironment": "node"
   }
 }

sample/14-mongoose-base/src/cats/cats.controller.spec.ts

@@ -0,0 +1,88 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { CatsController } from './cats.controller';
+import { CreateCatDto } from './dto/create-cat.dto';
+import { CatsService } from './cats.service';
+
+describe('CatsController', () => {
+  let controller: CatsController;
+  let service: CatsService;
+
+  beforeEach(async () => {
+    const module: TestingModule = await Test.createTestingModule({
+      controllers: [CatsController],
+      providers: [
+        {
+          provide: CatsService,
+          useValue: {
+            findAll: jest.fn().mockResolvedValue([
+              {
+                name: 'Cat #1',
+                breed: 'Bread #1',
+                age: 4,
+              },
+              {
+                name: 'Cat #2',
+                breed: 'Breed #2',
+                age: 3,
+              },
+              {
+                name: 'Cat #3',
+                breed: 'Breed #3',
+                age: 2,
+              },
+            ]),
+            create: jest
+              .fn()
+              .mockImplementation((createCatDto: CreateCatDto) =>
+                Promise.resolve({ _id: '1', ...createCatDto }),
+              ),
+          },
+        },
+      ],
+    }).compile();
+
+    controller = module.get(CatsController);
+    service = module.get(CatsService);
+  });
+
+  it('should be defined', () => {
+    expect(controller).toBeDefined();
+  });
+
+  describe('create()', () => {
+    it('should create a new cat', async () => {
+      const createCatDto: CreateCatDto = {
+        name: 'Cat #1',
+        breed: 'Breed #1',
+        age: 4,
+      };
+
+      expect(controller.create(createCatDto)).resolves.toEqual({
+        _id: '1',
+        ...createCatDto,
+      });
+    });
+  });
+
+  describe('findAll()', () => {
+    it('should get an array of cats', () => {
+      expect(controller.findAll()).resolves.toEqual([
+        {
+          name: 'Cat #1',
+          breed: 'Bread #1',
+          age: 4,
+        },
+        {
+          name: 'Cat #2',
+          breed: 'Breed #2',
+          age: 3,
+        },
+        {
+          name: 'Cat #3',
+          breed: 'Breed #3',
+          age: 2,
+        },
+      ]);
+    });
+  });
+});

sample/14-mongoose-base/src/cats/cats.controller.ts

@@ -9,7 +9,7 @@ export class CatsController {
 
   @Post()
   async create(@Body() createCatDto: CreateCatDto) {
-    this.catsService.create(createCatDto);
+    return this.catsService.create(createCatDto);
   }
 
   @Get()

sample/14-mongoose-base/src/cats/cats.service.spec.ts

@@ -0,0 +1,78 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { CatsService } from './cats.service';
+import { Cat } from './interfaces/cat.interface';
+import { Model } from 'mongoose';
+
+const mockCat = {
+  name: 'Cat #1',
+  breed: 'Breed #1',
+  age: 4,
+};
+
+describe('CatService', () => {
+  let service: CatsService;
+  let model: Model<Cat>;
+
+  const catsArray = [
+    {
+      name: 'Cat #1',
+      breed: 'Breed #1',
+      age: 4,
+    },
+    {
+      name: 'Cat #2',
+      breed: 'Breed #2',
+      age: 2,
+    },
+  ];
+
+  beforeEach(async () => {
+    const module: TestingModule = await Test.createTestingModule({
+      providers: [
+        CatsService,
+        {
+          provide: 'CAT_MODEL',
+          useValue: {
+            new: jest.fn().mockResolvedValue(mockCat),
+            constructor: jest.fn().mockResolvedValue(mockCat),
+            find: jest.fn(),
+            create: jest.fn(),
+            save: jest.fn(),
+            exec: jest.fn(),
+          },
+        },
+      ],
+    }).compile();
+
+    service = module.get(CatsService);
+    model = module.get<Model<Cat>>('CAT_MODEL');
+  });
+
+  it('should be defined', () => {
+    expect(service).toBeDefined();
+  });
+
+  it('should return all cats', async () => {
+    jest.spyOn(model, 'find').mockReturnValue({
+      exec: jest.fn().mockResolvedValueOnce(catsArray),
+    } as any);
+    const cats = await service.findAll();
+    expect(cats).toEqual(catsArray);
+  });
+
+  it('should insert a new cat', async () => {
+    jest.spyOn(model, 'create').mockImplementationOnce(() =>
+      Promise.resolve({
+        name: 'Cat #1',
+        breed: 'Breed #1',
+        age: 4,
+      }),
+    );
+    const newCat = await service.create({
+      name: 'Cat #1',
+      breed: 'Breed #1',
+      age: 4,
+    });
+    expect(newCat).toEqual(mockCat);
+  });
+});

sample/14-mongoose-base/src/cats/cats.service.ts

@@ -8,8 +8,8 @@ export class CatsService {
   constructor(@Inject('CAT_MODEL') private readonly catModel: Model<Cat>) {}
 
   async create(createCatDto: CreateCatDto): Promise<Cat> {
-    const createdCat = new this.catModel(createCatDto);
-    return createdCat.save();
+    const createdCat = this.catModel.create(createCatDto);
+    return createdCat;
   }
 
   async findAll(): Promise<Cat[]> {