[#12] feat: add env validation

backend/user-service/src/common/config.util.ts

@@ -0,0 +1,13 @@
+import { ValidationError } from 'class-validator'
+import { Config } from '../types/Config'
+import logger from './logger.util'
+
+const config: Config = Config.fromEnv(process.env)
+config.validateOrReject().catch((errors: ValidationError[]) => {
+    logger.error(
+        `[Config] Invalid or missing configuration: ${errors.map((error: ValidationError) => error.property).join(', ')}`
+    )
+    process.exit(1)
+})
+
+export default config

backend/user-service/src/server.ts

@@ -1,19 +1,13 @@
 import 'dotenv/config'
 import http, { Server } from 'http'
+import config from './common/config.util'
 import logger from './common/logger.util'
 import connectToDatabase from './common/mongodb.util'
 import index from './index'
 
-const port: string = process.env.PORT ?? '3000'
 const server: Server = http.createServer(index)
-server.listen(port, async () => {
-    logger.info(`[Init] Server is listening on port ${port}`)
+server.listen(config.PORT, async () => {
+    logger.info(`[Init] Server is listening on port ${config.PORT}`)
 })
 
-const connectionString: string | undefined = process.env.DB_URL
-if (!connectionString) {
-    logger.error(`[Init] DB_URL is not set`)
-    process.exit(1)
-}
-
-connectToDatabase(connectionString)
+connectToDatabase(config.DB_URL)

backend/user-service/src/types/Config.ts

@@ -0,0 +1,48 @@
+import { IsBase64, IsEnum, IsNotEmpty, IsNumberString, IsString, validateOrReject } from 'class-validator'
+
+export class Config {
+    @IsEnum(['development', 'production', 'test'])
+    NODE_ENV: string
+
+    @IsNumberString()
+    @IsNotEmpty()
+    PORT: string
+
+    @IsString()
+    @IsNotEmpty()
+    DB_URL: string
+
+    @IsBase64()
+    ACCESS_TOKEN_PRIVATE_KEY: string
+
+    @IsBase64()
+    ACCESS_TOKEN_PUBLIC_KEY: string
+
+    constructor(
+        NODE_ENV: string,
+        PORT: string,
+        DB_URL: string,
+        ACCESS_TOKEN_PRIVATE_KEY: string,
+        ACCESS_TOKEN_PUBLIC_KEY: string
+    ) {
+        this.NODE_ENV = NODE_ENV ?? 'development'
+        this.PORT = PORT ?? '3002'
+        this.DB_URL = DB_URL
+        this.ACCESS_TOKEN_PRIVATE_KEY = ACCESS_TOKEN_PRIVATE_KEY
+        this.ACCESS_TOKEN_PUBLIC_KEY = ACCESS_TOKEN_PUBLIC_KEY
+    }
+
+    static fromEnv(env: { [key: string]: string | undefined }): Config {
+        return new Config(
+            env.NODE_ENV!,
+            env.PORT!,
+            env.DB_URL!,
+            env.ACCESS_TOKEN_PRIVATE_KEY!,
+            env.ACCESS_TOKEN_PUBLIC_KEY!
+        )
+    }
+
+    async validateOrReject(): Promise<void> {
+        await validateOrReject(this)
+    }
+}