From 298fd50da5ee4a626283cf1ab6a7fb82c04e9def Mon Sep 17 00:00:00 2001
From: adrien guernier <adrien@marmelab.com>
Date: Thu, 5 Oct 2023 17:23:41 +0200
Subject: [PATCH 1/2] return undefined if field value is empty in useUnique

---
 packages/ra-core/src/form/useUnique.spec.tsx | 16 ++++++++++++++++
 packages/ra-core/src/form/useUnique.ts       |  3 +++
 2 files changed, 19 insertions(+)

diff --git a/packages/ra-core/src/form/useUnique.spec.tsx b/packages/ra-core/src/form/useUnique.spec.tsx
index c30f4544aa2..82400fa887a 100644
--- a/packages/ra-core/src/form/useUnique.spec.tsx
+++ b/packages/ra-core/src/form/useUnique.spec.tsx
@@ -258,4 +258,20 @@ describe('useUnique', () => {
         fireEvent.click(screen.getByText('Submit'));
         expect(screen.queryByText('Must be unique')).toBeNull();
     });
+
+    it('should not show an error when the field value is empty', async () => {
+        const dataProvider = baseDataProvider();
+        render(<Create dataProvider={dataProvider} />);
+
+        const input = await screen.findByDisplayValue('John Doe');
+        fireEvent.change(input, { target: { value: '' } });
+        fireEvent.click(screen.getByText('Submit'));
+
+        await waitFor(() => {
+            expect(dataProvider.create).toHaveBeenCalled();
+        });
+
+        expect(dataProvider.getList).not.toHaveBeenCalled();
+        expect(screen.queryByText('Must be unique')).toBeNull();
+    });
 });
diff --git a/packages/ra-core/src/form/useUnique.ts b/packages/ra-core/src/form/useUnique.ts
index c75861909a8..ca8650a7309 100644
--- a/packages/ra-core/src/form/useUnique.ts
+++ b/packages/ra-core/src/form/useUnique.ts
@@ -87,6 +87,9 @@ export const useUnique = (options?: UseUniqueOptions) => {
             );
 
             return async (value: any, allValues: any, props: InputProps) => {
+                if (!value) {
+                    return undefined;
+                }
                 try {
                     const finalFilter = set(
                         merge({}, filter),

From c45a8d14bc616b8774a4d617b65fd2dd2138b7f8 Mon Sep 17 00:00:00 2001
From: adrien guernier <adrien@marmelab.com>
Date: Fri, 6 Oct 2023 09:55:38 +0200
Subject: [PATCH 2/2] check if value is empty with isEmpty function

---
 packages/ra-core/src/form/useUnique.ts | 3 ++-
 packages/ra-core/src/form/validate.ts  | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/packages/ra-core/src/form/useUnique.ts b/packages/ra-core/src/form/useUnique.ts
index ca8650a7309..221a41c3059 100644
--- a/packages/ra-core/src/form/useUnique.ts
+++ b/packages/ra-core/src/form/useUnique.ts
@@ -7,6 +7,7 @@ import { useCallback, useRef } from 'react';
 import set from 'lodash/set';
 import { asyncDebounce } from '../util';
 import { useRecordContext } from '../controller';
+import { isEmpty } from './validate';
 
 /**
  * A hook that returns a validation function checking for a record field uniqueness
@@ -87,7 +88,7 @@ export const useUnique = (options?: UseUniqueOptions) => {
             );
 
             return async (value: any, allValues: any, props: InputProps) => {
-                if (!value) {
+                if (isEmpty(value)) {
                     return undefined;
                 }
                 try {
diff --git a/packages/ra-core/src/form/validate.ts b/packages/ra-core/src/form/validate.ts
index e865f69d546..33fa9ef332c 100644
--- a/packages/ra-core/src/form/validate.ts
+++ b/packages/ra-core/src/form/validate.ts
@@ -4,7 +4,7 @@ import lodashMemoize from 'lodash/memoize';
 /* @link http://stackoverflow.com/questions/46155/validate-email-address-in-javascript */
 const EMAIL_REGEX = /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/; // eslint-disable-line no-useless-escape
 
-const isEmpty = (value: any) =>
+export const isEmpty = (value: any) =>
     typeof value === 'undefined' ||
     value === null ||
     value === '' ||