explicit useEffect for clearing query whenever value is cleared

Author: david-crespo

app/forms/firewall-rules-common.tsx

@@ -125,10 +125,6 @@ const DynamicTypeAndValueFields = ({
       {/* In the firewall rules form, a few types get comboboxes instead of text fields */}
       {valueType === 'vpc' || valueType === 'subnet' || valueType === 'instance' ? (
         <ComboboxField
-          // key means we nuke the entire field when we change types. this fixes
-          // a bug where the firewall rule host filter combobox would keep an
-          // custom value query around when you change types
-          key={valueType}
           disabled={disabled}
           name="value"
           {...getFilterValueProps(valueType)}

app/ui/lib/Combobox.tsx

@@ -15,7 +15,7 @@ import {
 } from '@headlessui/react'
 import cn from 'classnames'
 import { matchSorter } from 'match-sorter'
-import { useId, useState, type ReactNode, type Ref } from 'react'
+import { useEffect, useId, useState, type ReactNode, type Ref } from 'react'
 
 import { SelectArrows6Icon } from '@oxide/design-system/icons/react'
 
@@ -97,6 +97,26 @@ export const Combobox = ({
     keys: ['selectedLabel', 'label'],
     sorter: (items) => items, // preserve original order, don't sort by match
   })
+
+  // In the arbitraryValues case, clear the query whenever the value is cleared.
+  // this is necessary, e.g., for the firewall rules form when you submit the
+  // targets subform and clear the field. Two possible changes we might want to make
+  // here if we run into issues:
+  //
+  //   1. do it all the time, not just in the arbitraryValues case
+  //   2. do it on all value changes, not just on clear
+  //
+  // Currently, I don't think there are any arbitraryValues=false cases where we
+  // set the value from outside. There is an arbitraryvalues=true case where we
+  // setValue to something other than empty string, but we don't need the
+  // sync because that setValue is done in onInputChange and we already are
+  // doing setQuery in here along with it.
+  useEffect(() => {
+    if (allowArbitraryValues && !selectedItemValue) {
+      setQuery('')
+    }
+  }, [allowArbitraryValues, selectedItemValue])
+
   // If the user has typed in a value that isn't in the list,
   // add it as an option if `allowArbitraryValues` is true
   if (

test/e2e/firewall-rules.e2e.ts

@@ -580,6 +580,18 @@ async function expectOptions(page: Page, options: string[]) {
 test('arbitrary values combobox', async ({ page }) => {
   await page.goto('/projects/mock-project/vpcs/mock-vpc/firewall-rules-new')
 
+  // test for bug where we'd persist the d after add and only show 'Custom: d'
+  const vpcInput = page.getByRole('combobox', { name: 'VPC name' }).first()
+  await vpcInput.focus()
+  await expectOptions(page, ['mock-vpc'])
+  await vpcInput.fill('d')
+  await expectOptions(page, ['Custom: d'])
+  await vpcInput.blur()
+  page.getByRole('button', { name: 'Add target' }).click()
+  await expect(vpcInput).toHaveValue('')
+  await vpcInput.focus()
+  await expectOptions(page, ['mock-vpc']) // bug cause failure here
+
   await selectOption(page, 'Target type', 'Instance')
   const input = page.getByRole('combobox', { name: 'Instance name' })