Pdt24 25 | Create a wrapper for environment variables

.env.example

@@ -1,13 +1,14 @@
 # Application
 APP_PORT=3000
-APP_ENV=development
+NODE_ENV=development  # development || production
 
 # Database
-POSTGRES_USER=trainee
-POSTGRES_PASSWORD=root9996
+DB_HOST=postgres
+POSTGRES_PORT=5432
+POSTGRES_USER=your_db_user
+POSTGRES_PASSWORD=your_db_password
 POSTGRES_DB=url_shortener
-POSTGRES_PORT= 5432
-DB_HOST= postgres
+
 
 # JWT
 JWT_SECRET=your_jwt_secret

docker-compose.yml

@@ -30,6 +30,7 @@ services:
       POSTGRES_PASSWORD: ${POSTGRES_PASSWORD}
       POSTGRES_DB: ${POSTGRES_DB}
       APP_PORT: ${APP_PORT}
+      NODE_ENV: ${NODE_ENV}
     ports:
       - ${APP_PORT}:${APP_PORT}
     networks:

package.json

@@ -39,7 +39,8 @@
 		"pg": "^8.13.1",
 		"reflect-metadata": "^0.2.0",
 		"rxjs": "^7.8.1",
-		"typeorm": "^0.3.20"
+		"typeorm": "^0.3.20",
+		"zod": "^3.24.1"
 	},
 	"devDependencies": {
 		"@commitlint/cli": "^19.6.0",

src/app.module.ts

@@ -1,11 +1,12 @@
 import { Module } from '@nestjs/common';
 import { AppController } from './app.controller';
 import { AppService } from './app.service';
+import { validate } from './config/env.config';
 import { ConfigModule } from '@nestjs/config';
 import { DatabaseModule } from './database/db.module';
 
 @Module({
-	imports: [ConfigModule.forRoot({ isGlobal: true }), DatabaseModule],
+	imports: [ConfigModule.forRoot({ isGlobal: true, validate }), DatabaseModule],
 	controllers: [AppController],
 	providers: [AppService],
 })

src/config/env.config.ts

@@ -0,0 +1,48 @@
+import { z } from 'zod';
+export const envVariables = {
+	POSTGRES_DB: process.env.POSTGRES_DB,
+	POSTGRES_USER: process.env.POSTGRES_USER,
+	POSTGRES_PASSWORD: process.env.POSTGRES_PASSWORD,
+	POSTGRES_PORT: +(process.env.POSTGRES_PORT || 5432),
+	DB_HOST: process.env.DB_HOST,
+	APP_PORT: +(process.env.APP_PORT || 3000),
+	NODE_ENV: process.env.NODE_ENV,
+	EMAIL_HOST: process.env.EMAIL_HOST,
+	EMAIL_PASS: process.env.EMAIL_PASS,
+	EMAIL_USER: process.env.EMAIL_USER,
+	EMAIL_PORT: +(process.env.EMAIL_PORT || 587),
+} as const;
+
+enum APP_ENVIRONVENT {
+	DEVELOPMENT = 'development',
+	PRODUCTION = 'production',
+}
+
+enum SMTP_PORTS {
+	STANDARD = 25,
+	DEFAULT = 587,
+	TLS = 465,
+}
+const validationSchema = z
+	.object({
+		POSTGRES_DB: z.string().min(2, { message: 'Must be atleast 2 characters long' }),
+		POSTGRES_USER: z.string().min(2, { message: 'Must be atleast 2 characters long' }),
+		POSTGRES_PASSWORD: z.string().min(2, { message: 'Must be atleast 2 characters long' }),
+		POSTGRES_PORT: z.number().gt(0, { message: 'Port cannot be empty' }),
+		DB_HOST: z.string().min(2, { message: 'Must be atleast 2 characters long' }),
+		APP_PORT: z.number().gt(0, { message: 'Port cannot be empty' }),
+		NODE_ENV: z.nativeEnum(APP_ENVIRONVENT),
+		EMAIL_HOST: z.string().min(2, { message: 'Must be atleast 2 characters long' }),
+		EMAIL_PORT: z.nativeEnum(SMTP_PORTS),
+		EMAIL_USER: z.string().min(2, { message: 'Must be atleast 2 characters long' }),
+		EMAIL_PASS: z.string().min(2, { message: 'Must be atleast 2 characters long' }),
+	})
+	.required();
+
+export const validate = (): object => {
+	const value = validationSchema.safeParse(envVariables);
+	if (!value.success) {
+		throw new Error(`---${value.error.issues[0].path} :: ${value.error.issues[0].message.toUpperCase()}---`);
+	}
+	return value.data;
+};

src/database/db.module.ts

@@ -2,13 +2,14 @@ import { Module } from '@nestjs/common';
 import { TypeOrmModule, TypeOrmModuleOptions } from '@nestjs/typeorm';
 import { dataBaseConfigurations } from 'src/scripts/orm.config';
 import { DataSource, DataSourceOptions, TypeORMError } from 'typeorm';
+import { envVariables } from '@/config/env.config';
 
 @Module({
 	imports: [
 		TypeOrmModule.forRootAsync({
 			useFactory: () => {
 				return {
-					host: process.env.DB_HOST,
+					host: envVariables.DB_HOST,
 					...dataBaseConfigurations,
 				} as TypeOrmModuleOptions;
 			},

src/main.ts

@@ -1,12 +1,12 @@
 import { NestFactory } from '@nestjs/core';
 import { AppModule } from './app.module';
+import { envVariables } from './config/env.config';
 
 async function bootstrap(): Promise<void> {
 	const app = await NestFactory.create(AppModule);
-
-	await app.listen(process.env.APP_PORT ?? 3000, () => {
-		console.info('Listening to server....');
-		console.info(`Server listening at port http://localhost:${process.env.APP_PORT}`);
+	const port = envVariables.APP_PORT;
+	await app.listen(port, () => {
+		console.info(`Server listening at port ${port}`);
 	});
 }
 

src/scripts/orm.config.ts

@@ -1,13 +1,14 @@
 import { writeFile } from 'fs/promises';
 import { join } from 'path';
 import { DataSource, DataSourceOptions } from 'typeorm';
+import { envVariables } from '@/config/env.config';
 
 const dataBaseConfigurations = {
 	type: 'postgres',
-	port: +(process.env.POSTGRES_PORT ?? '5432'),
-	username: process.env.POSTGRES_USER,
-	password: process.env.POSTGRES_PASSWORD,
-	database: process.env.POSTGRES_DB,
+	port: +(envVariables.POSTGRES_PORT ?? '5432'),
+	username: envVariables.POSTGRES_USER,
+	password: envVariables.POSTGRES_PASSWORD,
+	database: envVariables.POSTGRES_DB,
 	synchronize: false, // Should be false in production to use migrations
 	logging: true,
 	entities: [join(__dirname, '/../entities', '*.entity.{ts,js}')],

yarn.lock

@@ -4375,3 +4375,8 @@ yocto-queue@^1.0.0:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/yocto-queue/-/yocto-queue-1.1.1.tgz#fef65ce3ac9f8a32ceac5a634f74e17e5b232110"
   integrity sha512-b4JR1PFR10y1mKjhHY9LaGo6tmrgjit7hxVIeAmyMw3jegXR4dhYqLaQF5zMXZxY7tLpMyJeLjr1C4rLmkVe8g==
+
+zod@^3.24.1:
+  version "3.24.1"
+  resolved "https://registry.yarnpkg.com/zod/-/zod-3.24.1.tgz#27445c912738c8ad1e9de1bea0359fa44d9d35ee"
+  integrity sha512-muH7gBL9sI1nciMZV67X5fTKKBLtwpZ5VBp1vsOQzj1MhrBZ4wlVCm3gedKZWLp0Oyel8sIGfeiz54Su+OVT+A==