ConfigService is undefined while running testcases in Nest.js - jestjs

Question

I am running nestjs server locally and if I test with postman it works fine. But when I run testcases, the ConfigService gets undefined!
app.module.ts
#Module({
imports: [
ConfigModule.forRoot({ load: [configuration], isGlobal: true }),
AppDeployModule,
],
controllers: [AppController],
providers: [AppService],
})
export class AppModule {}
configuration.ts
export default () => ({
app: {
baseUrl: 'https://app-deploy.com',
},
});
app-deploy.controller.spec.ts
describe('AppDeployController', () => {
let controller: AppDeployController;
beforeEach(async () => {
const module: TestingModule = await Test.createTestingModule({
controllers: [AppDeployController],
providers: [AppDeployService],
imports: [ConfigModule],
}).compile();
controller = module.get<AppDeployController>(AppDeployController);
});
it.only('should create an app', async () => {
const res = await controller.create({ appName: 'Hello World' });
console.log(res);
});
});
Here in service file, configService.get('app') is undefined!
app-deploy.service.ts
#Injectable()
export class AppDeployService {
constructor(private configService: ConfigService) {}
create(createAppDeployDto: CreateAppDeployDto) {
console.log(this.configService.get('app')); // Here while running test it gets undefined
const baseUrl = this.configService.get('app').baseUrl;
return {
appName: createAppDeployDto.appName,
appUrl:
baseUrl +
'/' +
createAppDeployDto.appName.toLowerCase().replace(' ', '-'),
};
}
}
This is the result after running test.
FAIL src/app-deploy/app-deploy.controller.spec.ts
AppDeployController
× should create an app (51 ms)
● AppDeployController › should create an app
TypeError: Cannot read properties of undefined (reading 'baseUrl')
11 | console.log(this.configService.get('app')); // Here while running test it gets undefined
12 |
> 13 | const baseUrl = this.configService.get('app').baseUrl;
| ^
14 |
15 | return {
16 | appName: createAppDeployDto.appName,
at AppDeployService.create (app-deploy/app-deploy.service.ts:13:50)
at AppDeployController.create (app-deploy/app-deploy.controller.ts:12:34)
at Object.<anonymous> (app-deploy/app-deploy.controller.spec.ts:20:34)

Answer 1

In your app-deploy.controller.spec.ts, try to change this part of your code:
const module: TestingModule = await Test.createTestingModule({
controllers: [AppDeployController],
providers: [AppDeployService],
imports: [
ConfigModule.forRoot({
load: [configuration],
}),
],
}).compile();
controller = module.get<AppDeployController>(AppDeployController);