Custom configuration files in NestJS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the ConfigModule with a custom configuration file.

NestJS

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

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

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

AConfigModule

BConfigService

CconfigFile

DcustomConfig

Attempts:

3 left

💡 Hint

Common Mistakes

Passing ConfigService instead of the config function.

Using ConfigModule inside the load array.

Passing a string instead of a function or object.

You need to pass a function or object that returns your custom configuration. Here, customConfig is the correct import representing your config file.

2fill in blank

medium

Complete the code to create a custom configuration file exporting a function.

NestJS

export default function [1]() {
  return {
    port: parseInt(process.env.PORT, 10) || 3000,
  };
}

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

Aconfig

BConfigModule

CcustomConfig

DConfigService

Attempts:

3 left

💡 Hint

Common Mistakes

Using ConfigModule as function name.

Not exporting a default function.

Returning a non-object value.

The custom configuration file should export a default function, here named customConfig, that returns the configuration object.

3fill in blank

hard

Fix the error in the code to inject the ConfigService and get the custom port value.

NestJS

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

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

  getPort(): number {
    return this.configService.get<number>('port');
  }
}

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

AConfigModule

BConfigService

CcustomConfig

DConfig

Attempts:

3 left

💡 Hint

Common Mistakes

Injecting ConfigModule instead of ConfigService.

Using the config function name as type.

Forgetting to mark the constructor parameter as readonly.

You must inject ConfigService to access configuration values inside your service.

4fill in blank

hard

Fill both blanks to create a custom configuration file that reads a database URL and exports it.

NestJS

export default function [1]() {
  return {
    databaseUrl: process.env.[2] || 'mongodb://localhost:27017',
  };
}

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AdatabaseConfig

BDATABASE_URL

CDB_URL

Dconfig

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase or camelCase for environment variable names.

Using generic function names like config.

Forgetting to export a default function.

The function name databaseConfig is descriptive for database settings. The environment variable DATABASE_URL is a common standard for database connection strings.

5fill in blank

hard

Fill all three blanks to use the custom configuration in a service and get the database URL.

NestJS

import { Injectable } from '@nestjs/common';
import { [1] } from '@nestjs/config';

@Injectable()
export class DatabaseService {
  constructor(private readonly [2]: [1]) {}

  getDatabaseUrl(): string {
    return this.[2].get<string>('databaseUrl');
  }
}

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

AConfigService

BconfigService

CdatabaseConfig

DConfigModule

Attempts:

3 left

💡 Hint

Common Mistakes

Using ConfigModule instead of ConfigService.

Naming the injected variable the same as the class.

Importing the custom config function instead of ConfigService.

You import and inject ConfigService to access configuration values. The injected variable is commonly named configService.