FIX: keep a late create response out of a later dialog opening

The success path reset the form unconditionally, so a create response that
outlived its opening wiped the opening the user had moved on to: the typed
registry name, the selected type and its parameter rows all disappeared,
and reset() also cleared a submission error they were reading. Gate the
reset on the opening the request was submitted from, the same way the
failure path already gates setError, and leave onCreated ungated so a late
success still refreshes the list.

The submitting flag needed the same treatment, and clearing it when the
dialog opens rather than when a stale response lands, so a request from a
previous opening no longer re-enables the primary action of an opening that
has its own request in flight.

Author: v0ropaev

frontend/src/components/Registry/CreateConverterDialog.test.tsx

@@ -315,6 +315,37 @@ describe('CreateConverterDialog', () => {
     await waitFor(() => expect(alert).toHaveFocus())
   })
 
+  it('should not clear a later opening of the dialog when an earlier creation succeeds', async () => {
+    let resolveCreate: ((value: { converter_id: string }) => void) | undefined
+    mockedConvertersApi.createConverter.mockImplementation(
+      () => new Promise((resolve) => { resolveCreate = resolve }),
+    )
+    const onCreated = jest.fn()
+    const user = userEvent.setup()
+    const { rerender } = renderDialog({ onCreated })
+    await submitCaesarConverter(user)
+    await waitFor(() => expect(mockedConvertersApi.createConverter).toHaveBeenCalled())
+
+    // Dismissed while the request was in flight, then opened again and filled in.
+    rerender(dialogTree({ open: false, onCreated }))
+    rerender(dialogTree({ open: true, onCreated }))
+    await screen.findByRole('combobox', { name: /^converter type$/i })
+    await selectConverterType('CaesarConverter')
+    // Selecting a type prefills the registry name, so replace it rather than append.
+    await user.clear(screen.getByLabelText(/registry name/i))
+    await user.type(screen.getByLabelText(/registry name/i), 'my-second-converter')
+
+    await act(async () => {
+      resolveCreate?.({ converter_id: 'first-converter' })
+    })
+
+    // The list still refreshes, but the opening in front of the user is untouched.
+    expect(onCreated).toHaveBeenCalledWith('first-converter')
+    expect(screen.getByLabelText(/registry name/i)).toHaveValue('my-second-converter')
+    expect(screen.getByLabelText(/caesar_offset/i)).toBeInTheDocument()
+    expect(screen.getByRole('button', { name: 'Add Converter' })).toBeInTheDocument()
+  })
+
   it('should not surface a submission error in a later opening of the dialog', async () => {
     let rejectCreate: ((reason: Error) => void) | undefined
     mockedConvertersApi.createConverter.mockImplementation(

frontend/src/components/Registry/CreateConverterDialog.tsx

@@ -184,7 +184,8 @@ export default function CreateConverterDialog({
   const openEpochRef = useRef(0)
 
   useEffect(() => {
-    // Every change of `open` ends the opening before it.
+    // Every change of `open` ends the opening before it, so a response from the
+    // previous one leaves this opening's own state alone.
     openEpochRef.current += 1
     if (!open) return
     let cancelled = false
@@ -193,6 +194,9 @@ export default function CreateConverterDialog({
         if (cancelled) return null
         setLoading(true)
         setError(null)
+        // A request from the previous opening keeps its own "Adding..." state, so
+        // clear it here rather than letting that response clear it for this one.
+        setSubmitting(false)
         return Promise.all([
           convertersApi.listConverterTypes(),
           targetsApi.listTargets(200),
@@ -335,7 +339,12 @@ export default function CreateConverterDialog({
         type: selectedType,
         params: parameterValues,
       })
-      reset()
+      // Only the opening this request was submitted from is cleared: a response
+      // that outlived its opening must not wipe the form the user is filling in
+      // now. onCreated stays ungated so a late success still refreshes the list.
+      if (openEpochRef.current === epoch) {
+        reset()
+      }
       onCreated(response.converter_id)
     } catch (err) {
       // A failure from an opening the user has already left stays out of the
@@ -344,7 +353,9 @@ export default function CreateConverterDialog({
         setError({ message: toApiError(err).detail, fromSubmit: true })
       }
     } finally {
-      setSubmitting(false)
+      if (openEpochRef.current === epoch) {
+        setSubmitting(false)
+      }
     }
   }