Environment variables in NestJS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to load environment variables in a NestJS service.

NestJS

import { ConfigService } from '@nestjs/config';

@Injectable()
export class AppService {
  constructor(private readonly [1]: ConfigService) {}

  getDatabaseHost(): string {
    return this.configService.get<string>('DATABASE_HOST');
  }
}

Drag options to blanks, or click blank then click option'

AconfigSrv

BConfigService

Cconfig

DconfigService

Attempts:

3 left

💡 Hint

Common Mistakes

Using the class name instead of the instance name in the constructor.

Using a name that does not match the injected service.

The constructor parameter should be named configService to use the injected ConfigService instance.

2fill in blank

medium

Complete the code to access an environment variable named 'PORT' as a number.

NestJS

const port = this.configService.get<number>([1]);

Drag options to blanks, or click blank then click option'

A'port'

B'PORT'

C'Port'

D'server_port'

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase or mixed case keys that do not match the environment variable.

Using a wrong variable name.

Environment variables are case-sensitive and usually uppercase. The correct key is 'PORT'.

3fill in blank

hard

Fix the error in the code to correctly load environment variables in the main app module.

NestJS

import { ConfigModule } from '@nestjs/config';

@Module({
  imports: [ConfigModule.[1]()],
})
export class AppModule {}

Drag options to blanks, or click blank then click option'

Aload

Bregister

CforRoot

Dinit

Attempts:

3 left

💡 Hint

Common Mistakes

Using a non-existent method like 'load' or 'init'.

Forgetting to call the method as a function.

The ConfigModule must be imported with forRoot() to load environment variables globally.

4fill in blank

hard

Fill both blanks to create a configuration object that reads 'API_KEY' and 'API_SECRET' from environment variables.

NestJS

export default () => ({
  apiKey: process.env.[1],
  apiSecret: process.env.[2],
});

Drag options to blanks, or click blank then click option'

AAPI_KEY

Bapi_key

CAPI_SECRET

Dapi_secret

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase or camelCase keys that do not match environment variables.

Mixing up the keys for apiKey and apiSecret.

Environment variables are usually uppercase and underscore separated. Use API_KEY and API_SECRET.

5fill in blank

hard

Fill all three blanks to create a NestJS service method that returns the port number from environment variables with a default fallback.

NestJS

getPort(): number {
  return this.configService.get<number>([1], [2]) ?? [3];
}

Drag options to blanks, or click blank then click option'

A'PORT'

Bundefined

C3000

Dnull

Attempts:

3 left

💡 Hint

Common Mistakes

Passing wrong keys or default values.

Not providing a fallback value.

The method gets the 'PORT' variable, passes undefined as default value to get, and uses 3000 as fallback if undefined.