docs(recipies): add recipie for automock library

Author: omermorad

content/recipes/automock.md

@@ -0,0 +1,85 @@
+### AutoMock
+
+AutoMock is a standalone library for creating unit tests (specs). \
+Using TypeScript's reflection mechanism, it is able to mock class dependencies
+from the constructor level.
+
+### Installation
+
+Using AutoMock does not require any additional setup with Nest,
+simply install it and start using it.
+
+> info **info** Automock only supports `jest`, soon there will be support for `sinon` as well :)
+
+```bash
+$ npm i @automock/jest
+```
+
+### Examples
+
+Consider the following service:
+
+```ts
+// cats.service.ts
+import { Injectable } from '@nestjs/core';
+
+@Injectable()
+export class CatsService {
+  public constructor(
+    private readonly logger: Logger,
+    private readonly httpService: HttpService,
+    private readonly anotherService: AnotherService,
+  ) {}
+
+  public async getAllCats() {
+    const cats = await this.httpService.get('http://localhost:3033/cats');
+    this.logger.log(`Fetched all the cats!`)
+    
+    this.anotherService.doSomethingWithCats(cats);
+  }
+}
+```
+
+```ts
+// cats.service.spec.ts
+import { Spec } from '@automock/jest';
+import { CatsService } from './cats.service';
+
+import Mocked = jest.Mocked;
+
+describe('Cats Service Spec', () => {
+  let catsService: CatsService;
+  let logger: Mocked<Logger>;
+  let anotherService: Mocked<AnotherService>;
+  
+  beforeAll(() => {
+    const { unit, unitRef } = Spec.create(CatsService)
+      .mock(HttpService)
+      .using({ get: async () => Promise.resolve([{ id: 1, name: 'Catty' }]), })
+      .compile();
+    
+    catsService = unit;
+    logger = unitRef.get(Logger);
+    anotherService = unitRef.get(AnotherService);
+  });
+
+  describe('when getting all the cats', () => {
+    beforeAll(async () => await catsService.getAllCats());
+
+    test('then call the logger log', () => {
+      expect(logger.log).toBeCalled();
+    });
+
+    test('then do something with fetched data', () => {
+      expect(anotherService.doSomethingWithCats).toBeCalledWith([{ id: 1, name: 'Catty' }]);
+    });
+  });
+});
+```
+
+Nest suggests some built in tools for creating tests, usually you need to use the `Test` \
+factory from `@nestjs/testing` ([example]()) and create a new testing module. This technique \
+is great for creating integration/e2e tests, simply loading the whole module which includes all \
+the class dependencies
+
+> info **info** `Mocked` is exported from `jest`

src/app/homepage/menu/menu.component.ts

@@ -239,6 +239,7 @@ export class MenuComponent implements OnInit {
         { title: 'Prisma', path: '/recipes/prisma' },
         { title: 'Serve static', path: '/recipes/serve-static' },
         { title: 'Commander', path: '/recipes/nest-commander' },
+        { title: 'AutoMock', path: '/recipes/automock' },
       ],
     },
     {

src/app/homepage/pages/recipes/automock/automock.component.ts

@@ -0,0 +1,9 @@
+import { ChangeDetectionStrategy, Component } from '@angular/core';
+import { BasePageComponent } from '../../page/page.component';
+
+@Component({
+  selector: 'app-automock',
+  templateUrl: './automock.component.html',
+  changeDetection: ChangeDetectionStrategy.OnPush,
+})
+export class AutomockComponent extends BasePageComponent {}

src/app/homepage/pages/recipes/recipes.module.ts

@@ -15,6 +15,7 @@ import { SqlTypeormComponent } from './sql-typeorm/sql-typeorm.component';
 import { TerminusComponent } from './terminus/terminus.component';
 import { RouterModuleComponent } from './router-module/router-module.component';
 import { NestCommanderComponent } from './nest-commander/nest-commander.component';
+import { AutomockComponent } from './automock/automock.component';
 
 const routes: Routes = [
   {
@@ -94,6 +95,11 @@ const routes: Routes = [
     component: NestCommanderComponent,
     data: { title: 'Nest Commander' },
   },
+  {
+    path: 'automock',
+    component: AutomockComponent,
+    data: { title: 'AutoMock' },
+  },
 ];
 
 @NgModule({
@@ -112,6 +118,7 @@ const routes: Routes = [
     RouterModuleComponent,
     ServeStaticComponent,
     NestCommanderComponent,
+    AutomockComponent,
   ],
 })
 export class RecipesModule {}