fix: Added hook to combobox for when options change (trussworks#2715)

Co-authored-by: Shauna Keating <59394696+shkeating@users.noreply.github.com>

src/components/forms/ComboBox/ComboBox.stories.tsx

@@ -1,11 +1,11 @@
-import React, { useRef } from 'react'
+import React, { useRef, useState } from 'react'
 
 import { ComboBox, ComboBoxRef } from './ComboBox'
 import { Form } from '../Form/Form'
 import { Label } from '../Label/Label'
-import { TextInput } from '../TextInput/TextInput'
 import { Button } from '../../Button/Button'
-import { fruits } from './fruits'
+import { fruits, veggies } from './foods'
+import { Radio } from '../Radio/Radio'
 
 export default {
   title: 'Components/Combo box',
@@ -112,12 +112,42 @@ export const WithOtherFields = (): React.ReactElement => {
     label: key,
   }))
 
+  const veggieList = Object.entries(veggies).map(([value, key]) => ({
+    value: value,
+    label: key,
+  }))
+
+  const [options, setOptions] = useState(fruitList)
+
+  const ref = useRef<ComboBoxRef>(null)
+  const handleChange = (e: React.ChangeEvent<HTMLInputElement>) => {
+    ref.current?.clearSelection()
+    const selection = e.target.id
+    setOptions(selection === 'fruit' ? fruitList : veggieList)
+  }
+
   return (
     <Form onSubmit={noop}>
-      <Label htmlFor="fruit">Select a fruit</Label>
-      <ComboBox id="fruit" name="fruit" options={fruitList} onChange={noop} />
-      <Label htmlFor="fruitDescription">Description</Label>
-      <TextInput id="fruitDescription" name="fruitDescription" type="text" />
+      <Label htmlFor="food">Select a group</Label>
+      <Radio
+        name="food"
+        id="fruit"
+        label="Fruits"
+        onChange={handleChange}
+        defaultChecked></Radio>
+      <Radio
+        name="food"
+        id="veggie"
+        label="Vegetables"
+        onChange={handleChange}></Radio>
+      <Label htmlFor="food">Select a food</Label>
+      <ComboBox
+        id="fruit"
+        name="fruit"
+        options={options}
+        onChange={noop}
+        ref={ref}
+      />
     </Form>
   )
 }

src/components/forms/ComboBox/ComboBox.test.tsx

@@ -2,20 +2,29 @@ import React from 'react'
 import { screen, render, waitFor } from '@testing-library/react'
 import { userEvent } from '@testing-library/user-event'
 
-import { ComboBox, ComboBoxRef } from './ComboBox'
+import { ComboBox, ComboBoxOption, ComboBoxRef } from './ComboBox'
 import { TextInput } from '../TextInput/TextInput'
-import { fruits } from './fruits'
+import { fruits, veggies } from './foods'
 
 /*
   Source of truth for combo box behavior is USWDS storybook examples and tests. For more:
   - https://designsystem.digital.gov/form-controls/03-combo-box/
   - https://github.com/uswds/uswds/tree/7a89611fe649650922e4d431b78c39fed6a867e1/spec/unit/combo-box
 */
 
-const fruitOptions = Object.entries(fruits).map(([value, key]) => ({
-  value: value,
-  label: key,
-}))
+const fruitOptions: ComboBoxOption[] = Object.entries(fruits).map(
+  ([value, key]) => ({
+    value: value,
+    label: key,
+  })
+)
+
+const veggieOptions: ComboBoxOption[] = Object.entries(veggies).map(
+  ([value, key]) => ({
+    value: value,
+    label: key,
+  })
+)
 
 describe('ComboBox component', () => {
   it('renders the expected markup without errors', () => {
@@ -87,6 +96,24 @@ describe('ComboBox component', () => {
     expect(comboBoxInput).toHaveValue('Avocado')
   })
 
+  it('updates options when prop changes', async () => {
+    const Wrapper = (props: { options: ComboBoxOption[] }) => {
+      return (
+        <ComboBox
+          id="favorite-fruit"
+          name="favorite-fruit"
+          options={props.options}
+          onChange={vi.fn()}
+        />
+      )
+    }
+    const { rerender } = render(<Wrapper options={fruitOptions} />)
+    const comboBoxSelect = screen.getByTestId('combo-box-select')
+    expect(comboBoxSelect).toHaveValue(fruitOptions[0].value)
+    rerender(<Wrapper options={veggieOptions} />)
+    expect(comboBoxSelect).toHaveValue(veggieOptions[0].value)
+  })
+
   describe('toggling the list', () => {
     it('renders all options when the list is open', async () => {
       const fruitAbridged = fruitOptions.slice(0, 3)

src/components/forms/ComboBox/ComboBox.tsx

@@ -146,6 +146,10 @@ const ComboBoxForwardRef: React.ForwardRefRenderFunction<
   const listRef = useRef<HTMLUListElement>(null)
   const focusedItemRef = useRef<HTMLLIElement>(null)
 
+  useEffect(() => {
+    state.filteredOptions = options
+  }, [options])
+
   useEffect(() => {
     onChange && onChange(state.selectedOption?.value || undefined)
   }, [state.selectedOption])

src/components/forms/ComboBox/fruits.ts → src/components/forms/ComboBox/foods.ts

@@ -64,3 +64,9 @@ export const fruits = {
   'white currant': 'White currant',
   yuzu: 'Yuzu',
 }
+
+export const veggies = {
+  celery: 'Celery',
+  onion: 'Onion',
+  pepper: 'Pepper',
+}