fix: updating dashboard - initial save button state is "disabled" (el…

…astic#196137)

## Summary

This PR fixes [[Dashboard] User can click on update dashboard even
without changing
anything](elastic#187800) issue.

## Change

- When the flyout is open, the initial state of the button is
`disabled`.
- When there is a change made, the `disabled` state is removed.

![Screenshot 2024-10-14 at 15 21
28](https://github.com/user-attachments/assets/7f4a6234-959b-4779-bb4b-3f8bc221b3f2)

![Screenshot 2024-10-14 at 15 21
55](https://github.com/user-attachments/assets/24349b06-d6ee-4749-8981-d192eda8fd9d)

(cherry picked from commit 0ead257)

packages/content-management/content_editor/src/components/editor_flyout_content.tsx

@@ -79,6 +79,22 @@ export const ContentEditorFlyoutContent: FC<Props> = ({
   const i18nTexts = useMemo(() => getI18nTexts({ entityName }), [entityName]);
   const form = useMetadataForm({ item, customValidators });
 
+  const hasNoChanges = () => {
+    const itemTags = item.tags.map((obj) => obj.id).sort();
+    const formTags = form.tags.value.slice().sort();
+
+    const compareTags = (arr1: string[], arr2: string[]) => {
+      if (arr1.length !== arr2.length) return false;
+      return arr1.every((tag: string, index) => tag === arr2[index]);
+    };
+
+    return (
+      item.title === form.title.value &&
+      item.description === form.description.value &&
+      compareTags(itemTags, formTags)
+    );
+  };
+
   const onClickSave = useCallback(async () => {
     if (form.isValid && onSave && !form.getIsChangingValue()) {
       const id = item.id;
@@ -177,7 +193,7 @@ export const ContentEditorFlyoutContent: FC<Props> = ({
                   onClick={onClickSave}
                   data-test-subj="saveButton"
                   fill
-                  disabled={isSubmitted && !form.isValid}
+                  disabled={(isSubmitted && !form.isValid) || hasNoChanges()}
                   isLoading={isSubmitting}
                 >
                   {i18nTexts.saveButtonLabel}

packages/content-management/content_editor/src/components/inspector_flyout_content.test.tsx

@@ -104,32 +104,37 @@ describe('<ContentEditorFlyoutContent />', () => {
       expect(find('saveButton').text()).toBe('Update foo');
     });
 
-    test('should send back the updated item to the onSave() handler', async () => {
+    test('should save form only if something changes', async () => {
       const onSave = jest.fn();
 
       await act(async () => {
         testBed = await setup({ onSave, isReadonly: false });
       });
 
-      const {
-        find,
-        component,
-        form: { setInputValue },
-      } = testBed!;
-
-      await waitForValidationResults();
+      const { find, component } = testBed!;
 
       await act(async () => {
         find('saveButton').simulate('click');
       });
 
-      expect(onSave).toHaveBeenCalledWith({
-        id: '123',
-        title: 'Foo',
-        description: 'Some description',
-        tags: ['id-1', 'id-2'],
+      component.update();
+
+      expect(onSave).not.toHaveBeenCalled();
+    });
+
+    test('should send back the updated item to the onSave() handler', async () => {
+      const onSave = jest.fn();
+
+      await act(async () => {
+        testBed = await setup({ onSave, isReadonly: false });
       });
 
+      const {
+        find,
+        component,
+        form: { setInputValue },
+      } = testBed!;
+
       await act(async () => {
         setInputValue('metadataForm.nameInput', 'newTitle');
         setInputValue('metadataForm.descriptionInput', 'newDescription');
@@ -196,7 +201,17 @@ describe('<ContentEditorFlyoutContent />', () => {
         testBed = await setup({ onSave, isReadonly: false, services: { notifyError } });
       });
 
-      const { find, component } = testBed!;
+      const {
+        find,
+        component,
+        form: { setInputValue },
+      } = testBed!;
+
+      await act(async () => {
+        setInputValue('metadataForm.nameInput', 'changingTitleToUnblockDisabledButtonState');
+      });
+
+      await waitForValidationResults();
 
       component.update();