nest_config_module_configurations.ts

import { Module } from '@nestjs/common';
import { ConfigModule } from '@nestjs/config';
import * as Joi from 'joi';

@Module({
  imports: [
    ConfigModule.forRoot({
      isGlobal: true, // Makes config available across the app
      envFilePath: `.env.${process.env.NODE_ENV || 'development'}`, // Load specific .env file based on NODE_ENV
      ignoreEnvFile: process.env.NODE_ENV === 'production', // Ignore .env in production (use external env variables)
      expandVariables: true, // Enables ${VAR_NAME} expansion in .env files
      validationSchema: Joi.object({
        PORT: Joi.number().default(3000), // Ensures PORT is a number, defaults to 3000
        DATABASE_URL: Joi.string().required(), // Ensures DATABASE_URL is provided
        JWT_SECRET: Joi.string().min(10).required(), // Requires JWT_SECRET with a min length of 10
      }),
    }),
  ],
})
export class AppModule {}