chore(deps): update vitest monorepo to v4 (major) (#3410)

* chore(deps): update vitest monorepo to v4

* Fix mocking

---------

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: Richard Dominick <34370238+RichDom2185@users.noreply.github.com>

Author: renovate[bot]

package.json

@@ -150,8 +150,8 @@
     "@types/showdown": "^2.0.1",
     "@types/xml2js": "^0.4.11",
     "@vitejs/plugin-react-swc": "^4.0.0",
-    "@vitest/coverage-v8": "3.2.4",
-    "@vitest/ui": "^3.2.4",
+    "@vitest/coverage-v8": "4.0.6",
+    "@vitest/ui": "^4.0.0",
     "buffer": "^6.0.3",
     "canvas": "^3.1.0",
     "constants-browserify": "^1.0.0",
@@ -184,7 +184,7 @@
     "typescript": "^5.8.2",
     "typescript-eslint": "^8.1.0",
     "url": "^0.11.1",
-    "vitest": "^3.2.4",
+    "vitest": "^4.0.0",
     "webpack-bundle-analyzer": "^4.9.0"
   },
   "browserslist": {

src/commons/utils/__tests__/RequestHelper.test.ts

@@ -83,13 +83,21 @@ const mockPostRefresh = (success: boolean) =>
 
 const mockNetworkErrorOnce = () => fetchMock.mockImplementationOnce(() => Promise.reject());
 
+// Make `Headers` return a singleton for easier comparison in tests
+const originalHeaders = global.Headers;
+const singleton = new originalHeaders();
+vi.spyOn(global, 'Headers').mockImplementation(function (init?: HeadersInit) {
+  return singleton;
+});
+
 const makeRequest = (method: RequestMethod = GET_METHOD) => request(apiPath, method, fetchOptions);
 const expectFetchToBeCalledWithCorrectParams = () =>
   expect(fetchMock).toBeCalledWith(
     fullApiUrl,
     generateApiCallHeadersAndFetchOptions(GET_METHOD, fetchOptions)
   );
 const expectRefreshFlowFetchesToBeCalledWithCorrectParams = () => {
+  expect(fetchMock).toBeCalledTimes(2);
   expect(fetchMock).toHaveBeenNthCalledWith(
     1,
     fullApiUrl,
@@ -100,6 +108,16 @@ const expectRefreshFlowFetchesToBeCalledWithCorrectParams = () => {
     fullApiUrl,
     expect.objectContaining(generateApiCallHeadersAndFetchOptions(GET_METHOD, refreshFetchOptions))
   );
+  // expect(fetchMock).toHaveBeenNthCalledWith(
+  //   1,
+  //   fullApiUrl,
+  //   expect.objectContaining(generateApiCallHeadersAndFetchOptions(GET_METHOD, fetchOptions))
+  // );
+  // expect(fetchMock).toHaveBeenNthCalledWith(
+  //   2,
+  //   fullApiUrl,
+  //   expect.objectContaining(generateApiCallHeadersAndFetchOptions(GET_METHOD, refreshFetchOptions))
+  // );
 };
 const expectPostRefreshToBeCalled = (called: boolean) =>
   called ? expect(postRefreshSpy).toBeCalledTimes(1) : expect(postRefreshSpy).not.toBeCalled();