Fix clearing species comment during edits

frontend/src/components/DetailView/components.tsx

@@ -118,8 +118,15 @@ export const WriteButton = <T,>({
       const convertedEditData = convertSpeciesTaxonomyFields(editData as EditDataType<Species>)
       const convertedOriginalData = convertSpeciesTaxonomyFields(data as EditDataType<Species>)
       const taxonomyHasChanged = mode.new || hasTaxonomyChanges(convertedEditData, convertedOriginalData)
+      const sanitizedEditData =
+        'sp_comment' in convertedEditData
+          ? {
+              ...convertedEditData,
+              sp_comment: convertedEditData.sp_comment === '' ? null : convertedEditData.sp_comment,
+            }
+          : convertedEditData
 
-      speciesEditData = convertedEditData
+      speciesEditData = sanitizedEditData
 
       if (taxonomyHasChanged) {
         if (!speciesData) {
@@ -139,7 +146,7 @@ export const WriteButton = <T,>({
       }
 
       notify('', undefined, 0)
-      setEditData(convertedEditData as EditDataType<T>)
+      setEditData(sanitizedEditData as EditDataType<T>)
 
       if (hasStagingMode) {
         setMode(mode.new ? 'staging-new' : 'staging-edit')

frontend/src/tests/components/SpeciesWriteButton.test.tsx

@@ -87,10 +87,14 @@ const baseSpecies: Species = {
   locomo2: '',
   locomo3: '',
   sp_author: '',
-  sp_comment: '',
+  sp_comment: 'Existing comment',
 }
 
-const renderButton = (editData: EditDataType<Species>, onWrite = jest.fn(() => Promise.resolve())) => {
+const renderButton = (
+  editData: EditDataType<Species>,
+  onWrite = jest.fn(() => Promise.resolve()),
+  overrides?: Partial<DetailContextType<Species>>
+) => {
   mockUseDetailContext.mockReturnValue({
     data: baseSpecies,
     mode: modeEdit,
@@ -105,6 +109,7 @@ const renderButton = (editData: EditDataType<Species>, onWrite = jest.fn(() => P
     validator,
     fieldsWithErrors: {},
     setFieldsWithErrors: jest.fn(),
+    ...overrides,
   })
 
   mockUseGetAllSpeciesQuery.mockReturnValue({ data: [baseSpecies] } as never)
@@ -147,4 +152,20 @@ describe('WriteButton taxonomy handling', () => {
     expect(onWrite).not.toHaveBeenCalled()
     expect(mockNotify).toHaveBeenCalledWith(expect.stringContaining('taxon already exists'), 'error', null)
   })
+
+  it('converts a cleared comment field to null so it can be persisted', async () => {
+    const onWrite = jest.fn(() => Promise.resolve())
+    const setEditData = jest.fn()
+
+    renderButton({ ...baseSpecies, sp_comment: '' } as EditDataType<Species>, onWrite, { setEditData })
+
+    fireEvent.click(screen.getByRole('button', { name: /save changes/i }))
+
+    await waitFor(() => {
+      expect(onWrite).toHaveBeenCalledTimes(1)
+    })
+
+    expect(onWrite).toHaveBeenCalledWith(expect.objectContaining({ sp_comment: null }), expect.any(Function))
+    expect(setEditData).toHaveBeenCalledWith(expect.objectContaining({ sp_comment: null }))
+  })
 })