[RadioGroup] Random default name (mui#19890)

docs/pages/api/radio-group.md

@@ -26,7 +26,7 @@ You can learn more about the difference by [reading this guide](/guides/minimizi
 |:-----|:-----|:--------|:------------|
 | <span class="prop-name">children</span> | <span class="prop-type">node</span> |  | The content of the component. |
 | <span class="prop-name">defaultValue</span> | <span class="prop-type">any</span> |  | The default `input` element value. Use when the component is not controlled. |
-| <span class="prop-name">name</span> | <span class="prop-type">string</span> |  | The name used to reference the value of the control. |
+| <span class="prop-name">name</span> | <span class="prop-type">string</span> |  | The name used to reference the value of the control. If you don't provide this prop, it falls back to a randomly generated name. |
 | <span class="prop-name">onChange</span> | <span class="prop-type">func</span> |  | Callback fired when a radio button is selected.<br><br>**Signature:**<br>`function(event: object) => void`<br>*event:* The event source of the callback. You can pull out the new value by accessing `event.target.value` (string). |
 | <span class="prop-name">value</span> | <span class="prop-type">any</span> |  | Value of the selected radio button. The DOM API casts this to a string. |
 

packages/material-ui/src/RadioGroup/RadioGroup.js

@@ -6,7 +6,7 @@ import useControlled from '../utils/useControlled';
 import RadioGroupContext from './RadioGroupContext';
 
 const RadioGroup = React.forwardRef(function RadioGroup(props, ref) {
-  const { actions, children, name, value: valueProp, onChange, ...other } = props;
+  const { actions, children, name: nameProp, value: valueProp, onChange, ...other } = props;
   const rootRef = React.useRef(null);
 
   const [value, setValue] = useControlled({
@@ -43,6 +43,15 @@ const RadioGroup = React.forwardRef(function RadioGroup(props, ref) {
     }
   };
 
+  const [defaultName, setDefaultName] = React.useState();
+  const name = nameProp || defaultName;
+  React.useEffect(() => {
+    // Fallback to this default name when possible.
+    // Use the random value for client-side rendering only.
+    // We can't use it server-side.
+    setDefaultName(`mui-radiogroup-${Math.round(Math.random() * 1e5)}`);
+  }, []);
+
   return (
     <RadioGroupContext.Provider value={{ name, onChange: handleChange, value }}>
       <FormGroup role="radiogroup" ref={handleRef} {...other}>
@@ -67,6 +76,7 @@ RadioGroup.propTypes = {
   defaultValue: PropTypes.any,
   /**
    * The name used to reference the value of the control.
+   * If you don't provide this prop, it falls back to a randomly generated name.
    */
   name: PropTypes.string,
   /**

packages/material-ui/src/RadioGroup/RadioGroup.test.js

@@ -85,6 +85,18 @@ describe('<RadioGroup />', () => {
     assert.strictEqual(findRadio(wrapper, 'one').props().checked, true);
   });
 
+  it('should have a default name', () => {
+    const wrapper = mount(
+      <RadioGroup>
+        <Radio value="zero" />
+        <Radio value="one" />
+      </RadioGroup>,
+    );
+
+    assert.match(findRadio(wrapper, 'zero').props().name, /^mui-radiogroup-[0-9]+/);
+    assert.match(findRadio(wrapper, 'one').props().name, /^mui-radiogroup-[0-9]+/);
+  });
+
   describe('imperative focus()', () => {
     it('should focus the first non-disabled radio', () => {
       const actionsRef = React.createRef();
@@ -295,6 +307,16 @@ describe('<RadioGroup />', () => {
         setProps({ value: 'one' });
         expect(radioGroupRef.current).to.have.property('value', 'one');
       });
+
+      it('should have a default name from the instance', () => {
+        const radioGroupRef = React.createRef();
+        const { setProps } = render(<RadioGroupControlled ref={radioGroupRef} />);
+
+        expect(radioGroupRef.current.name).to.match(/^mui-radiogroup-[0-9]+/);
+
+        setProps({ name: 'anotherGroup' });
+        expect(radioGroupRef.current).to.have.property('name', 'anotherGroup');
+      });
     });
 
     describe('callbacks', () => {