refactor(config): add env parsing helpers and tighten startup validation

src/app.module.ts

@@ -12,13 +12,24 @@ import { RedisModule } from './database/redis.module';
 import { WsModule } from './ws/ws.module';
 import { FriendsModule } from './friends/friends.module';
 import { DollsModule } from './dolls/dolls.module';
+import { parseRedisRequired } from './common/config/env.utils';
 
 /**
  * Validates required environment variables.
  * Throws an error if any required variables are missing or invalid.
  * Returns the validated config.
  */
-function validateEnvironment(config: Record<string, any>): Record<string, any> {
+function getOptionalEnvString(
+  config: Record<string, unknown>,
+  key: string,
+): string | undefined {
+  const value = config[key];
+  return typeof value === 'string' ? value : undefined;
+}
+
+function validateEnvironment(
+  config: Record<string, unknown>,
+): Record<string, unknown> {
   const requiredVars = ['JWT_SECRET', 'DATABASE_URL'];
 
   const missingVars = requiredVars.filter((varName) => !config[varName]);
@@ -30,10 +41,44 @@ function validateEnvironment(config: Record<string, any>): Record<string, any> {
   }
 
   // Validate PORT if provided
-  if (config.PORT && isNaN(Number(config.PORT))) {
+  if (config.PORT !== undefined && !Number.isFinite(Number(config.PORT))) {
     throw new Error('PORT must be a valid number');
   }
 
+  if (config.NODE_ENV === 'production') {
+    if (
+      typeof config.JWT_SECRET !== 'string' ||
+      config.JWT_SECRET.length < 32
+    ) {
+      throw new Error(
+        'JWT_SECRET must be at least 32 characters in production',
+      );
+    }
+  }
+
+  const redisRequired = parseRedisRequired({
+    nodeEnv: getOptionalEnvString(config, 'NODE_ENV'),
+    redisRequired: getOptionalEnvString(config, 'REDIS_REQUIRED'),
+  });
+
+  if (redisRequired && !config.REDIS_HOST) {
+    throw new Error(
+      'REDIS_REQUIRED is enabled but REDIS_HOST is not configured',
+    );
+  }
+
+  const redisConnectTimeout = getOptionalEnvString(
+    config,
+    'REDIS_CONNECT_TIMEOUT_MS',
+  );
+  if (
+    redisConnectTimeout !== undefined &&
+    (!Number.isFinite(Number(redisConnectTimeout)) ||
+      Number(redisConnectTimeout) <= 0)
+  ) {
+    throw new Error('REDIS_CONNECT_TIMEOUT_MS must be a positive number');
+  }
+
   validateOptionalProvider(config, 'GOOGLE');
   validateOptionalProvider(config, 'DISCORD');
 
@@ -41,7 +86,7 @@ function validateEnvironment(config: Record<string, any>): Record<string, any> {
 }
 
 function validateOptionalProvider(
-  config: Record<string, any>,
+  config: Record<string, unknown>,
   provider: 'GOOGLE' | 'DISCORD',
 ): void {
   const vars = [