fix(multiselect): add useEffect to selection hook to update externally (

#16139)

* fix(multiselect): add useEffect to selection hook to update externally

* chore: add ychavoya to contributors

* fix(multiselect): pass value instead of the result of the state setter

the setter function of a useState hook returns undefined, this was mistakenly
used as the value to be set instead of sending the value directly

---------

Co-authored-by: TJ Egan <[email protected]>

.all-contributorsrc

@@ -1515,6 +1515,15 @@
       "contributions": [
         "code"
       ]
+    },
+    {
+      "login": "ychavoya",
+      "name": "Yael Chavoya",
+      "avatar_url": "https://avatars.githubusercontent.com/u/7907338?v=4",
+      "profile": "https://github.com/ychavoya",
+      "contributions": [
+        "code"
+      ]
     }
   ],
   "commitConvention": "none"

README.md

@@ -289,6 +289,7 @@ check out our [Contributing Guide](/.github/CONTRIBUTING.md) and our
     <td align="center"><a href="https://hollyos.com/"><img src="https://avatars.githubusercontent.com/u/4097509?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Holly Springsteen</b></sub></a><br /><a href="https://github.com/carbon-design-system/carbon/commits?author=hollyos" title="Code">💻</a></td>
     <td align="center"><a href="https://github.com/2nikhiltom"><img src="https://avatars.githubusercontent.com/2nikhiltom?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Nikhil Tomar</b></sub></a><br /><a href="https://github.com/carbon-design-system/carbon/commits?author=2nikhiltom" title="Code">💻</a></td>
     <td align="center"><a href="https://github.com/aninaantony"><img src="https://avatars.githubusercontent.com/u/164350784?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Anina Antony</b></sub></a><br /><a href="https://github.com/carbon-design-system/carbon/commits?author=aninaantony" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/ychavoya"><img src="https://avatars.githubusercontent.com/u/7907338?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Yael Chavoya</b></sub></a><br /><a href="https://github.com/carbon-design-system/carbon/commits?author=ychavoya" title="Code">💻</a></td>
   </tr>
 </table>
 

packages/react/src/components/MultiSelect/MultiSelect.stories.js

@@ -5,13 +5,16 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import React from 'react';
+import React, { useState } from 'react';
+import { action } from '@storybook/addon-actions';
 
 import { WithLayer } from '../../../.storybook/templates/WithLayer';
 import mdx from './MultiSelect.mdx';
 
 import MultiSelect from '.';
 import FilterableMultiSelect from './FilterableMultiSelect';
+import Button from '../Button';
+import ButtonSet from '../ButtonSet';
 
 export default {
   title: 'Components/MultiSelect',
@@ -306,3 +309,41 @@ export const _FilterableWithLayer = () => (
     )}
   </WithLayer>
 );
+
+export const _Controlled = () => {
+  const [selectedItems, setSelectedItems] = useState(
+    items.filter((item) => item.id === 'downshift-1-item-0')
+  );
+
+  const onSelectionChanged = (value) => {
+    action('changed items')(value);
+    setSelectedItems(value);
+  };
+
+  return (
+    <div style={{ width: 300 }}>
+      <MultiSelect
+        id="carbon-multiselect-example-controlled"
+        titleText="Multiselect title"
+        label="Multiselect label"
+        items={items}
+        selectedItems={selectedItems}
+        onChange={(data) => onSelectionChanged(data.selectedItems)}
+        itemToString={(item) => (item ? item.text : '')}
+        selectionFeedback="top-after-reopen"
+      />
+      <br />
+      <ButtonSet>
+        <Button id="all" onClick={() => setSelectedItems(items)}>
+          Select all
+        </Button>
+        <Button
+          id="clear"
+          kind="secondary"
+          onClick={() => setSelectedItems([])}>
+          Clear
+        </Button>
+      </ButtonSet>
+    </div>
+  );
+};

packages/react/src/components/MultiSelect/__tests__/MultiSelect-test.js

@@ -6,7 +6,7 @@
  */
 
 import { getByText, isElementVisible } from '@carbon/test-utils/dom';
-import { render, screen } from '@testing-library/react';
+import { act, render, screen } from '@testing-library/react';
 import React from 'react';
 import MultiSelect from '../';
 import { generateItems, generateGenericItem } from '../../ListBox/test-helpers';
@@ -455,7 +455,7 @@ describe('MultiSelect', () => {
       expect(translateWithId).toHaveBeenCalled();
     });
 
-    it('should call onChange when the selection changes', async () => {
+    it('should call onChange when the selection changes from user selection', async () => {
       const testFunction = jest.fn();
       const items = generateItems(4, generateGenericItem);
       const label = 'test-label';
@@ -482,6 +482,30 @@ describe('MultiSelect', () => {
       expect(testFunction).toHaveBeenCalledTimes(1);
     });
 
+    it('should call onChange when the selection changes outside of the component', () => {
+      const handleChange = jest.fn();
+      const items = generateItems(4, generateGenericItem);
+      const props = {
+        id: 'custom-id',
+        onChange: handleChange,
+        selectedItems: [],
+        label: 'test-label',
+        items,
+      };
+      const { rerender } = render(<MultiSelect {...props} />);
+
+      expect(handleChange).not.toHaveBeenCalled();
+
+      act(() => {
+        rerender(<MultiSelect {...props} selectedItems={[items[0]]} />);
+      });
+
+      expect(handleChange).toHaveBeenCalledTimes(1);
+      expect(handleChange.mock.lastCall[0]).toMatchObject({
+        selectedItems: [items[0]],
+      });
+    });
+
     it('should support an invalid state with invalidText that describes the field', () => {
       const items = generateItems(4, generateGenericItem);
       const label = 'test-label';

packages/react/src/internal/Selection.js

@@ -39,6 +39,11 @@ export function useSelection({
   const [selectedItems, setSelectedItems] = useState(
     isControlled ? controlledItems : uncontrolledItems
   );
+
+  useEffect(() => {
+    setSelectedItems(isControlled ? controlledItems : uncontrolledItems);
+  }, [isControlled, controlledItems, uncontrolledItems]);
+
   useEffect(() => {
     callOnChangeHandler({
       isControlled,
@@ -80,7 +85,7 @@ export function useSelection({
       isMounted: isMounted.current,
       onChangeHandlerControlled: savedOnChange.current,
       onChangeHandlerUncontrolled: setUncontrolledItems,
-      selectedItems: setSelectedItems([]),
+      selectedItems: [],
     });
   }, [disabled, isControlled]);