Fix fetch action redirect (#37437)

And add tests for its behavior

web_src/js/features/common-fetch-action.test.ts

@@ -1,4 +1,4 @@
-import {execPseudoSelectorCommands} from './common-fetch-action.ts';
+import {execPseudoSelectorCommands, handleFetchActionSuccessJson} from './common-fetch-action.ts';
 
 test('execPseudoSelectorCommands', () => {
   window.document.body.innerHTML = `
@@ -37,3 +37,23 @@ test('execPseudoSelectorCommands', () => {
   expect(ret.targets.length).toEqual(2);
   expect(ret.targets).toEqual(Array.from(document.querySelectorAll('#d1 .x')));
 });
+
+test('handleFetchActionSuccessJson', async () => {
+  const spyAssign = vi.spyOn(window.location, 'assign').mockImplementation(() => {});
+  const spyReload = vi.spyOn(window.location, 'reload').mockImplementation(() => {});
+
+  await handleFetchActionSuccessJson(document.body, {redirect: '/'});
+  expect(spyAssign).toHaveBeenCalledTimes(1);
+  expect(spyReload).toHaveBeenCalledTimes(0);
+  vi.resetAllMocks();
+
+  await handleFetchActionSuccessJson(document.body, {redirect: ''});
+  expect(spyAssign).toHaveBeenCalledTimes(0);
+  expect(spyReload).toHaveBeenCalledTimes(1);
+  vi.resetAllMocks();
+
+  await handleFetchActionSuccessJson(document.body, {});
+  expect(spyAssign).toHaveBeenCalledTimes(0);
+  expect(spyReload).toHaveBeenCalledTimes(1);
+  vi.resetAllMocks();
+});

web_src/js/features/common-fetch-action.ts

@@ -34,7 +34,7 @@ function fetchActionDoRedirect(redirect: string) {
   // * Also do so in development, to make sure the redirection logic is always tested by real users
   const needBackendHelp = redirect.includes('#');
   if (runModeIsProd && !needBackendHelp) {
-    window.location.href = redirect;
+    window.location.assign(redirect);
     return;
   }
 
@@ -66,11 +66,13 @@ function toggleLoadingIndicator(el: HTMLElement, opt: FetchActionOpts, isLoading
   }
 }
 
-async function handleFetchActionSuccessJson(el: HTMLElement, respJson: any) {
+export async function handleFetchActionSuccessJson(el: HTMLElement, respJson: any) {
   ignoreAreYouSure(el); // ignore the areYouSure check before reloading
-  if (typeof respJson?.redirect === 'string') {
-    fetchActionDoRedirect(respJson.redirect);
+  const redirect = respJson?.redirect;
+  if (typeof redirect === 'string' && redirect) {
+    fetchActionDoRedirect(redirect);
   } else {
+    // reserved behavior, in the future, there can be more fields to introduce more behaviors
     window.location.reload();
   }
 }