fix(test): add jest setup for Next.js 15 compatibility

- Polyfill TextEncoder/TextDecoder (jsdom lacks these)
- Mock next-runtime-env to avoid loading Next.js server stack
  (next/cache pulls Request/Response/ReadableStream not in jsdom)
- Fixes CI test failures (ReferenceError: TextEncoder is not defined)

Author: christoph2806

jest.config.js

@@ -11,7 +11,7 @@ const createJestConfig = nextJest({
 /** @type {import('jest').Config} */
 const customJestConfig = {
     // Add more setup options before each test is run
-    // setupFilesAfterEnv: ['<rootDir>/jest.setup.js'],
+    setupFiles: ['<rootDir>/jest.setup.js'],
     // if using TypeScript with a baseUrl set to the root directory then you need the below for alias' to work
     moduleDirectories: ['node_modules', '<rootDir>/'],
     testEnvironment: 'jest-environment-jsdom',

jest.setup.js

@@ -0,0 +1,18 @@
+// Polyfill TextEncoder/TextDecoder for Next.js 15 in Jest (jsdom lacks these)
+const { TextEncoder, TextDecoder } = require('util');
+global.TextEncoder = TextEncoder;
+global.TextDecoder = TextDecoder;
+
+// Mock next-runtime-env to avoid loading Next.js server stack (next/cache, etc.)
+jest.mock('next-runtime-env', () => ({
+    PublicEnvProvider: ({ children }) => children,
+    useEnvContext: () => ({
+        NEXT_PUBLIC_PREMIUM_TOKEN_SYMBOL: 'FUSD',
+        NEXT_PUBLIC_PRODUCT_CONTRACT_ADDRESS: '0x0000000000000000000000000000000000000000',
+        NEXT_PUBLIC_FLIGHT_NFT_CONTRACT_ADDRESS: '0x0000000000000000000000000000000000000000',
+        NEXT_PUBLIC_AIRPORTS_WHITELIST: '',
+        NEXT_PUBLIC_AIRPORTS_BLACKLIST: '',
+        NEXT_PUBLIC_DEPARTURE_DATE_DATE_FROM: undefined,
+        NEXT_PUBLIC_DEPARTURE_DATE_MIN_DAYS: '14',
+    }),
+}));