Adds front-end set-up

frontend/src/test/setup.ts

@@ -0,0 +1,45 @@
+import '@testing-library/jest-dom/vitest';
+import { afterAll, afterEach, beforeAll, vi } from 'vitest';
+import { cleanup } from '@testing-library/react';
+import { server } from '@/mocks/server';
+import { api } from '@/lib/api-client';
+import '@/i18n/config';
+
+// jsdom is missing a few browser APIs that Radix/sonner touch.
+const globalAny = globalThis as unknown as {
+    matchMedia?: unknown;
+    ResizeObserver?: unknown;
+};
+
+if (typeof globalAny.matchMedia === 'undefined') {
+    globalAny.matchMedia = vi.fn().mockImplementation((query: string) => ({
+        matches: false,
+        media: query,
+        onchange: null,
+        addListener: vi.fn(),
+        removeListener: vi.fn(),
+        addEventListener: vi.fn(),
+        removeEventListener: vi.fn(),
+        dispatchEvent: vi.fn(),
+    }));
+}
+
+if (typeof globalAny.ResizeObserver === 'undefined') {
+    globalAny.ResizeObserver = class {
+        observe() {}
+        unobserve() {}
+        disconnect() {}
+    };
+}
+
+beforeAll(() => server.listen({ onUnhandledRequest: 'error' }));
+
+afterEach(() => {
+    cleanup();
+    server.resetHandlers();
+    // Reset shared client state between tests.
+    api.setAccessToken(null);
+    localStorage.clear();
+});
+
+afterAll(() => server.close());