Fix ReferenceFieldBase considers zero-index reference as empty

Author: fzaninotto

packages/ra-core/src/controller/field/ReferenceFieldBase.spec.tsx

@@ -12,6 +12,7 @@ import {
     Meta,
     Offline,
     WithRenderProp,
+    ZeroIndex,
 } from './ReferenceFieldBase.stories';
 import { RecordContextProvider } from '../record';
 import { onlineManager } from '@tanstack/react-query';
@@ -184,4 +185,11 @@ describe('<ReferenceFieldBase />', () => {
         await screen.findByText('You are offline, the data may be outdated');
         await screen.findByText('Leo');
     });
+
+    it('should not render the empty component for zero-index ids', async () => {
+        render(<ZeroIndex />);
+        await waitFor(() => {
+            expect(screen.queryByText('Leo')).not.toBeNull();
+        });
+    });
 });

packages/ra-core/src/controller/field/ReferenceFieldBase.stories.tsx

@@ -268,18 +268,16 @@ export const QueryOptions = () => (
 const BookShowMeta = () => {
     return (
         <ShowBase>
-            <>
-                <TextField source="title" />
-                <ReferenceFieldBase
-                    reference="authors"
-                    source="author"
-                    queryOptions={{ meta: { test: true } }}
-                >
-                    <MyReferenceField>
-                        <TextField source="last_name" />
-                    </MyReferenceField>
-                </ReferenceFieldBase>
-            </>
+            <TextField source="title" />
+            <ReferenceFieldBase
+                reference="authors"
+                source="author"
+                queryOptions={{ meta: { test: true } }}
+            >
+                <MyReferenceField>
+                    <TextField source="last_name" />
+                </MyReferenceField>
+            </ReferenceFieldBase>
         </ShowBase>
     );
 };
@@ -397,6 +395,55 @@ export const WithRenderProp = ({ dataProvider = dataProviderWithAuthors }) => (
     </TestMemoryRouter>
 );
 
+export const ZeroIndex = ({
+    dataProvider = fakeRestDataProvider(
+        {
+            books: [
+                {
+                    id: 1,
+                    title: 'War and Peace',
+                    author: 0,
+                    summary:
+                        "War and Peace broadly focuses on Napoleon's invasion of Russia, and the impact it had on Tsarist society. The book explores themes such as revolution, revolution and empire, the growth and decline of various states and the impact it had on their economies, culture, and society.",
+                    year: 1869,
+                },
+            ],
+            authors: [
+                {
+                    id: 0,
+                    first_name: 'Leo',
+                    last_name: 'Tolstoy',
+                    language: 'Russian',
+                },
+            ],
+        },
+        process.env.NODE_ENV === 'development'
+    ),
+}: {
+    dataProvider?: DataProvider;
+}) => (
+    <TestMemoryRouter initialEntries={['/books/1/show']}>
+        <CoreAdmin dataProvider={dataProvider}>
+            <Resource
+                name="books"
+                show={() => (
+                    <ShowBase>
+                        <TextField source="title" />
+                        <ReferenceFieldBase
+                            reference="authors"
+                            source="author"
+                            empty={<>Should not appear</>}
+                        >
+                            <TextField source="first_name" />
+                            <TextField source="last_name" />
+                        </ReferenceFieldBase>
+                    </ShowBase>
+                )}
+            />
+        </CoreAdmin>
+    </TestMemoryRouter>
+);
+
 export const Offline = () => {
     return (
         <TestMemoryRouter initialEntries={['/books/1/show']}>

packages/ra-core/src/controller/field/ReferenceFieldBase.tsx

@@ -77,7 +77,7 @@ export const ReferenceFieldBase = <
         !!controllerError && error !== false && error !== undefined;
     const shouldRenderEmpty =
         !isPaused &&
-        (!id ||
+        (id == null ||
             (!referenceRecord &&
                 !controllerError &&
                 !isPending &&