[App Search] Relevance Tuning: Fix unsaved changes bug (#104951)

* Fix unsavedChanges false positive when MultiInputRows is present

- The fix for this is to change MultiInputRows from useEffect to useUpdateEffect, which prevents onChange from firing on initial mount/render (triggering updateBoostValue->unsavedChanges)

@see https://github.com/streamich/react-use/blob/master/docs/useUpdateEffect.md

* Fix precision tuner not triggering unsavedChanges

x-pack/plugins/enterprise_search/public/applications/app_search/components/multi_input_rows/multi_input_rows.test.tsx

@@ -10,7 +10,7 @@ import '../../../__mocks__/shallow_useeffect.mock';
 
 import React from 'react';
 
-import { shallow } from 'enzyme';
+import { shallow, ShallowWrapper } from 'enzyme';
 
 import { rerender } from '../../../test_helpers';
 
@@ -162,10 +162,18 @@ describe('MultiInputRows', () => {
   });
 
   describe('onChange', () => {
+    let wrapper: ShallowWrapper;
     const onChange = jest.fn();
 
+    beforeEach(() => {
+      wrapper = shallow(<MultiInputRows {...props} onChange={onChange} />);
+    });
+
+    it('does not call on change on mount', () => {
+      expect(onChange).not.toHaveBeenCalled();
+    });
+
     it('returns the current values dynamically on change', () => {
-      const wrapper = shallow(<MultiInputRows {...props} onChange={onChange} />);
       setMockValues({ ...values, values: ['updated'] });
       rerender(wrapper);
 

x-pack/plugins/enterprise_search/public/applications/app_search/components/multi_input_rows/multi_input_rows.tsx

@@ -5,9 +5,10 @@
  * 2.0.
  */
 
-import React, { useEffect } from 'react';
+import React from 'react';
 
 import { useValues, useActions } from 'kea';
+import useUpdateEffect from 'react-use/lib/useUpdateEffect';
 
 import { EuiForm, EuiButton, EuiButtonEmpty, EuiSpacer } from '@elastic/eui';
 
@@ -49,7 +50,7 @@ export const MultiInputRows: React.FC<Props> = ({
   const { values, addedNewRow, hasEmptyValues, hasOnlyOneValue } = useValues(logic);
   const { addValue, editValue, deleteValue } = useActions(logic);
 
-  useEffect(() => {
+  useUpdateEffect(() => {
     if (onChange) {
       onChange(filterEmptyValues(values));
     }

x-pack/plugins/enterprise_search/public/applications/app_search/components/relevance_tuning/relevance_tuning_logic.test.ts

@@ -229,7 +229,7 @@ describe('RelevanceTuningLogic', () => {
     });
 
     describe('updatePrecision', () => {
-      it('should set precision inside search settings', () => {
+      it('should set precision inside search settings and set unsavedChanges to true', () => {
         mount();
         RelevanceTuningLogic.actions.updatePrecision(9);
 
@@ -239,6 +239,7 @@ describe('RelevanceTuningLogic', () => {
             ...DEFAULT_VALUES.searchSettings,
             precision: 9,
           },
+          unsavedChanges: true,
         });
       });
     });

x-pack/plugins/enterprise_search/public/applications/app_search/components/relevance_tuning/relevance_tuning_logic.ts

@@ -191,6 +191,7 @@ export const RelevanceTuningLogic = kea<
     unsavedChanges: [
       false,
       {
+        updatePrecision: () => true,
         setSearchSettings: () => true,
         setSearchSettingsResponse: () => false,
       },