[8.9] [Dashboard] Fix missing state on short URL alias match redirect (…

…#163658) (#163746)

# Backport

This will backport the following commits from `main` to `8.9`:
- [[Dashboard] Fix missing state on short URL alias match redirect
(#163658)](#163658)

<!--- Backport version: 8.9.7 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sqren/backport)

<!--BACKPORT [{"author":{"name":"Devon
Thomson","email":"devon.thomson@elastic.co"},"sourceCommit":{"committedDate":"2023-08-11T16:15:18Z","message":"[Dashboard]
Fix missing state on short URL alias match redirect (#163658)\n\nFixes
an issue where URL state from short URLs could be lost on an alias match
redirect.","sha":"4de61111b14b59d2b57758a35ef47618c3a9ba46","branchLabelMapping":{"^v8.10.0$":"main","^v(\\d+).(\\d+).\\d+$":"$1.$2"}},"sourcePullRequest":{"labels":["Feature:Dashboard","release_note:fix","Team:Presentation","loe:hours","impact:high","backport:prev-minor","v8.10.0","v8.9.2"],"number":163658,"url":"#163658
Fix missing state on short URL alias match redirect (#163658)\n\nFixes
an issue where URL state from short URLs could be lost on an alias match
redirect.","sha":"4de61111b14b59d2b57758a35ef47618c3a9ba46"}},"sourceBranch":"main","suggestedTargetBranches":["8.9"],"targetPullRequestStates":[{"branch":"main","label":"v8.10.0","labelRegex":"^v8.10.0$","isSourceBranch":true,"state":"MERGED","url":"#163658
Fix missing state on short URL alias match redirect (#163658)\n\nFixes
an issue where URL state from short URLs could be lost on an alias match
redirect.","sha":"4de61111b14b59d2b57758a35ef47618c3a9ba46"}},{"branch":"8.9","label":"v8.9.2","labelRegex":"^v(\\d+).(\\d+).\\d+$","isSourceBranch":false,"state":"NOT_CREATED"}]}]
BACKPORT-->

src/plugins/dashboard/public/dashboard_container/embeddable/create/create_dashboard.test.ts

@@ -51,14 +51,32 @@ test('throws error when provided validation function returns invalid', async ()
   }).rejects.toThrow('Dashboard failed saved object result validation');
 });
 
-test('returns undefined when provided validation function returns redireted', async () => {
+test('returns undefined when provided validation function returns redirected', async () => {
   const creationOptions: DashboardCreationOptions = {
     validateLoadedSavedObject: jest.fn().mockImplementation(() => 'redirected'),
   };
   const dashboard = await createDashboard(creationOptions, 0, 'test-id');
   expect(dashboard).toBeUndefined();
 });
 
+/**
+ * Because the getInitialInput function may have side effects, we only want to call it once we are certain that the
+ * the loaded saved object passes validation.
+ *
+ * This is especially relevant in the Dashboard App case where calling the getInitialInput function removes the _a
+ * param from the URL. In alais match situations this caused a bug where the state from the URL wasn't properly applied
+ * after the redirect.
+ */
+test('does not get initial input when provided validation function returns redirected', async () => {
+  const creationOptions: DashboardCreationOptions = {
+    validateLoadedSavedObject: jest.fn().mockImplementation(() => 'redirected'),
+    getInitialInput: jest.fn(),
+  };
+  const dashboard = await createDashboard(creationOptions, 0, 'test-id');
+  expect(dashboard).toBeUndefined();
+  expect(creationOptions.getInitialInput).not.toHaveBeenCalled();
+});
+
 test('pulls state from dashboard saved object when given a saved object id', async () => {
   pluginServices.getServices().dashboardContentManagement.loadDashboardState = jest
     .fn()

src/plugins/dashboard/public/dashboard_container/embeddable/create/create_dashboard.ts

@@ -137,7 +137,6 @@ export const initializeDashboard = async ({
     useUnifiedSearchIntegration,
     useSessionStorageIntegration,
   } = creationOptions ?? {};
-  const overrideInput = getInitialInput?.();
 
   // --------------------------------------------------------------------------------------
   // Run validation.
@@ -161,6 +160,7 @@ export const initializeDashboard = async ({
   // --------------------------------------------------------------------------------------
   // Combine input from saved object, session storage, & passed input to create initial input.
   // --------------------------------------------------------------------------------------
+  const overrideInput = getInitialInput?.();
   const initialInput: DashboardContainerInput = cloneDeep({
     ...DEFAULT_DASHBOARD_INPUT,
     ...(loadDashboardReturn?.dashboardInput ?? {}),