feat: implement environment variable validation with class-validator and class-transformer

server/src/app.module.ts

@@ -1,21 +1,21 @@
-import * as fs from 'fs';
-
 import { Logger, Module } from '@nestjs/common';
 import { ConfigModule, ConfigService } from '@nestjs/config';
 import { MongooseModule, MongooseModuleFactoryOptions } from '@nestjs/mongoose';
 
+import { validate } from 'class-validator';
 import { AuthModule } from './auth/auth.module';
 import { FileModule } from './file/file.module';
 import { ParseTokenPipe } from './parseToken';
-import { SongModule } from './song/song.module';
 import { SongBrowserModule } from './song-browser/song-browser.module';
+import { SongModule } from './song/song.module';
 import { UserModule } from './user/user.module';
 
 @Module({
   imports: [
     ConfigModule.forRoot({
       isGlobal: true,
       envFilePath: ['.env.development', '.env.production'],
+      validate: validate,
     }),
     //DatabaseModule,
     MongooseModule.forRootAsync({
@@ -44,46 +44,4 @@ import { UserModule } from './user/user.module';
   providers: [ParseTokenPipe],
   exports: [ParseTokenPipe],
 })
-export class AppModule {
-  private readonly logger = new Logger(AppModule.name);
-  constructor(private readonly configService: ConfigService) {
-    // read .env.development.example file
-    const file = '.env.development.example';
-    const encoding = 'utf8';
-    const fileData = fs.readFileSync(file, encoding);
-
-    const variableToIgnore = ['APP_DOMAIN', 'NODE_ENV', 'WHITELISTED_USERS'];
-
-    const variables = fileData
-      .split('\n')
-      // trim whitespace
-      .map((line) => line.trim())
-      // remove empty lines
-      .filter((line) => line.length > 0)
-      // get variable names
-      .map((line) => line.split('=')[0])
-      // remove variables that are not in the .env.development.example file
-      .filter((variable) => !variableToIgnore.includes(variable));
-
-    this.logger.warn(`Ignoring variables: ${variableToIgnore.join(', ')}`);
-    this.logger.warn(`Checking variables: ${variables.join(', ')}`);
-
-    let isMissing = false;
-
-    for (const variable of variables) {
-      const value = this.configService.get(variable);
-
-      if (!value) {
-        this.logger.error(
-          `Missing environment variable ${variable} in env vars}`,
-        );
-
-        isMissing = true;
-      }
-    }
-
-    if (isMissing) {
-      throw new Error('Missing environment variables in env vars file');
-    }
-  }
-}
+export class AppModule {}

server/src/config/EnvironmentVariables.ts

@@ -0,0 +1,100 @@
+import { plainToInstance } from 'class-transformer';
+import { IsEnum, IsOptional, IsString, validateSync } from 'class-validator';
+
+enum Environment {
+  Development = 'development',
+  Production = 'production',
+}
+
+export class EnvironmentVariables {
+  @IsEnum(Environment)
+  @IsOptional()
+  NODE_ENV?: Environment;
+
+  @IsString()
+  GITHUB_CLIENT_ID: string;
+
+  @IsString()
+  GITHUB_CLIENT_SECRET: string;
+
+  @IsString()
+  GOOGLE_CLIENT_ID: string;
+
+  @IsString()
+  GOOGLE_CLIENT_SECRET: string;
+
+  @IsString()
+  DISCORD_CLIENT_ID: string;
+
+  @IsString()
+  DISCORD_CLIENT_SECRET: string;
+
+  @IsString()
+  JWT_SECRET: string;
+
+  @IsString()
+  JWT_EXPIRES_IN: string;
+
+  @IsString()
+  JWT_REFRESH_SECRET: string;
+
+  @IsString()
+  JWT_REFRESH_EXPIRES_IN: string;
+
+  @IsString()
+  MONGO_URL: string;
+
+  @IsString()
+  SERVER_URL: string;
+
+  @IsString()
+  FRONTEND_URL: string;
+
+  @IsString()
+  @IsOptional()
+  APP_DOMAIN?: string;
+
+  @IsString()
+  RECAPTCHA_KEY: string;
+
+  @IsString()
+  S3_ENDPOINT: string;
+
+  @IsString()
+  S3_BUCKET_SONGS: string;
+
+  @IsString()
+  S3_BUCKET_THUMBS: string;
+
+  @IsString()
+  S3_KEY: string;
+
+  @IsString()
+  S3_SECRET: string;
+
+  @IsString()
+  S3_REGION: string;
+
+  @IsString()
+  @IsOptional()
+  WHITELISTED_USERS?: string;
+
+  @IsString()
+  DISCORD_WEBHOOK_URL: string;
+}
+
+export function validate(config: Record<string, unknown>) {
+  const validatedConfig = plainToInstance(EnvironmentVariables, config, {
+    enableImplicitConversion: true,
+  });
+
+  const errors = validateSync(validatedConfig, {
+    skipMissingProperties: false,
+  });
+
+  if (errors.length > 0) {
+    throw new Error(errors.toString());
+  }
+
+  return validatedConfig;
+}