formating and env documentation

web/src/lib/config.ts

@@ -0,0 +1,30 @@
+import { z } from 'zod';
+
+type Env = z.infer<typeof envSchema>;
+const envSchema = z.object({
+    STORE_MODE: z.enum(['hotel', 'airline'], {
+        errorMap: () => ({ message: 'STORE_MODE must be either "hotel" or "airline"' })
+    }),
+    NEXT_PUBLIC_API_BASE: z.string().url({
+        message: 'NEXT_PUBLIC_API_BASE must be a valid URL (e.g., http://localhost:3000)'
+    }),
+    NEXT_PUBLIC_APP_ENV: z.enum(['dev', 'prod'], {
+        errorMap: () => ({ message: 'NEXT_PUBLIC_APP_ENV must be either "dev" or "prod"' })
+    }),
+});
+
+// parse and validate env at module load, fail fast with descriptive errors
+const parseEnv = (): Env => {
+    const result = envSchema.safeParse({
+        STORE_MODE: process.env.STORE_MODE,
+        NEXT_PUBLIC_API_BASE: process.env.NEXT_PUBLIC_API_BASE,
+        NEXT_PUBLIC_APP_ENV: process.env.NEXT_PUBLIC_APP_ENV,
+    });
+    if (!result.success) {
+        const errors = result.error.errors.map((err) => `${err.path.join('.')}: ${err.message}`).join('\n');
+        throw new Error(`Environment validation failed:\n${errors}`);
+    }
+    return result.data;
+};
+
+export const config: Env = parseEnv();