Fix TS error

Author: fzaninotto

packages/ra-ui-materialui/src/input/DateInput.spec.tsx

@@ -8,7 +8,7 @@ import { useFormState } from 'react-hook-form';
 import { AdminContext } from '../AdminContext';
 import { SimpleForm } from '../form';
 import { DateInput } from './DateInput';
-import { Basic } from './DateInput.stories';
+import { Basic, Parse } from './DateInput.stories';
 
 describe('<DateInput />', () => {
     const defaultProps = {
@@ -139,14 +139,11 @@ describe('<DateInput />', () => {
     it('should accept a parse function', async () => {
         const onSubmit = jest.fn();
         render(
-            <Basic
+            <Parse
                 simpleFormProps={{
                     onSubmit,
                     defaultValues: { publishedAt: new Date('2021-09-11') },
                 }}
-                dateInputProps={{
-                    parse: val => new Date(val),
-                }}
             />
         );
         const input = screen.getByLabelText('Published at') as HTMLInputElement;

packages/ra-ui-materialui/src/input/DateInput.stories.tsx

@@ -94,8 +94,8 @@ export const Validate = () => (
     </Wrapper>
 );
 
-export const Parse = () => (
-    <Wrapper>
+export const Parse = ({ simpleFormProps }) => (
+    <Wrapper simpleFormProps={simpleFormProps}>
         <DateInput source="publishedAt" parse={value => new Date(value)} />
     </Wrapper>
 );

packages/ra-ui-materialui/src/input/DateInput.tsx

@@ -256,10 +256,12 @@ const defaultFormat = (value: string | Date | number) => {
         return convertDateToString(value);
     }
 
-    // Valid date strings should be stripped of their time  and timezone parts.
-    const matches = dateRegex.exec(value);
-    if (matches) {
-        return matches[1];
+    // Valid date strings should be stripped of their time and timezone parts.
+    if (typeof value === 'string') {
+        const matches = dateRegex.exec(value);
+        if (matches) {
+            return matches[1];
+        }
     }
 
     // other values (e.g., localized date strings, timestamps) need to be converted to Dates first