Initial commit: NestJS backend for Child Gold Land

Co-authored-by: Cursor <cursoragent@cursor.com>

src/config/env.validation.ts

@@ -0,0 +1,60 @@
+import { plainToInstance } from 'class-transformer'
+import { IsIn, IsInt, IsOptional, IsString, Min, validateSync } from 'class-validator'
+
+export class EnvironmentVariables {
+  @IsIn(['development', 'production', 'test'])
+  NODE_ENV!: 'development' | 'production' | 'test'
+
+  @IsInt()
+  @Min(1)
+  PORT!: number
+
+  @IsString()
+  HOST!: string
+
+  @IsString()
+  CORS_ORIGIN!: string
+
+  @IsOptional()
+  @IsString()
+  DB_PATH?: string
+
+  @IsOptional()
+  @IsString()
+  JWT_SECRET?: string
+}
+
+export function validateEnv(config: Record<string, unknown>): EnvironmentVariables {
+  const nodeEnv = (config.NODE_ENV as string | undefined) ?? 'development'
+  const jwtSecret = config.JWT_SECRET as string | undefined
+
+  if (nodeEnv === 'production' && (!jwtSecret || jwtSecret.trim().length === 0)) {
+    throw new Error('JWT_SECRET is required when NODE_ENV=production')
+  }
+
+  if (nodeEnv !== 'production' && !jwtSecret) {
+    console.warn(
+      '[config] JWT_SECRET is not set — using development fallback. Do not use in production.',
+    )
+  }
+
+  const normalized = {
+    NODE_ENV: nodeEnv,
+    PORT: Number(config.PORT ?? 3001),
+    HOST: (config.HOST as string | undefined) ?? '0.0.0.0',
+    CORS_ORIGIN: (config.CORS_ORIGIN as string | undefined) ?? 'http://localhost:5173',
+    DB_PATH: config.DB_PATH as string | undefined,
+    JWT_SECRET: jwtSecret ?? 'gold-land-dev-secret-change-in-production',
+  }
+
+  const validated = plainToInstance(EnvironmentVariables, normalized, {
+    enableImplicitConversion: true,
+  })
+
+  const errors = validateSync(validated, { skipMissingProperties: false })
+  if (errors.length > 0) {
+    throw new Error(errors.toString())
+  }
+
+  return validated
+}