[ExpansionPanel] Use context instead of cloneElement

packages/material-ui/src/ExpansionPanel/Context.js

@@ -0,0 +1,9 @@
+import React from 'react';
+
+/**
+ * @ignore - internal component.
+ * @type {React.Context<{} | {expanded: boolean, disabled: boolean, toggle: () => void}>}
+ */
+const Context = React.createContext({});
+
+export default Context;

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

@@ -5,6 +5,7 @@ import { chainPropTypes } from '@material-ui/utils';
 import Collapse from '../Collapse';
 import Paper from '../Paper';
 import withStyles from '../styles/withStyles';
+import Context from './Context';
 
 export const styles = theme => {
   const transition = {
@@ -115,17 +116,25 @@ const ExpansionPanel = React.forwardRef(function ExpansionPanel(props, ref) {
     }, [expandedProp, isControlled]);
   }
 
-  const handleChange = event => {
-    if (!isControlled) {
-      setExpandedState(!expanded);
-    }
+  const handleChange = React.useCallback(
+    event => {
+      if (!isControlled) {
+        setExpandedState(!expanded);
+      }
 
-    if (onChange) {
-      onChange(event, !expanded);
-    }
-  };
+      if (onChange) {
+        onChange(event, !expanded);
+      }
+    },
+    [expanded, isControlled, onChange],
+  );
 
   const [summary, ...children] = React.Children.toArray(childrenProp);
+  const contextValue = React.useMemo(() => ({ expanded, disabled, toggle: handleChange }), [
+    expanded,
+    disabled,
+    handleChange,
+  ]);
 
   return (
     <Paper
@@ -142,11 +151,7 @@ const ExpansionPanel = React.forwardRef(function ExpansionPanel(props, ref) {
       square={square}
       {...other}
     >
-      {React.cloneElement(summary, {
-        disabled,
-        expanded,
-        onChange: handleChange,
-      })}
+      <Context.Provider value={contextValue}>{summary}</Context.Provider>
       <TransitionComponent in={expanded} timeout="auto" {...TransitionProps}>
         <div aria-labelledby={summary.props.id} id={summary.props['aria-controls']} role="region">
           {children}

packages/material-ui/src/ExpansionPanelSummary/ExpansionPanelSummary.d.ts

@@ -8,11 +8,8 @@ export type ExpansionPanelSummaryTypeMap<
   D extends React.ElementType = 'div'
 > = ExtendButtonBaseTypeMap<{
   props: P & {
-    disabled?: boolean;
-    expanded?: boolean;
     expandIcon?: React.ReactNode;
     IconButtonProps?: Partial<IconButtonProps>;
-    onChange?: React.ReactEventHandler<{}>;
   };
   defaultComponent: D;
   classKey: ExpansionPanelSummaryClassKey;

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

@@ -5,6 +5,7 @@ import clsx from 'clsx';
 import ButtonBase from '../ButtonBase';
 import IconButton from '../IconButton';
 import withStyles from '../styles/withStyles';
+import ExpansionPanelContext from '../ExpansionPanel/Context';
 
 export const styles = theme => {
   const transition = {
@@ -68,12 +69,9 @@ const ExpansionPanelSummary = React.forwardRef(function ExpansionPanelSummary(pr
     children,
     classes,
     className,
-    disabled = false,
-    expanded,
     expandIcon,
     IconButtonProps,
     onBlur,
-    onChange,
     onClick,
     onFocusVisible,
     ...other
@@ -94,10 +92,11 @@ const ExpansionPanelSummary = React.forwardRef(function ExpansionPanelSummary(pr
       onBlur(event);
     }
   };
-  // TODO: Remove in v5 and use onClick in ExpansionPanel.js
+
+  const { disabled = false, expanded, toggle } = React.useContext(ExpansionPanelContext);
   const handleChange = event => {
-    if (onChange) {
-      onChange(event);
+    if (toggle) {
+      toggle(event);
     }
     if (onClick) {
       onClick(event);
@@ -160,16 +159,6 @@ ExpansionPanelSummary.propTypes = {
    * @ignore
    */
   className: PropTypes.string,
-  /**
-   * @ignore
-   * If `true`, the summary will be displayed in a disabled state.
-   */
-  disabled: PropTypes.bool,
-  /**
-   * @ignore
-   * If `true`, expands the summary, otherwise collapse it.
-   */
-  expanded: PropTypes.bool,
   /**
    * The icon to display as the expand indicator.
    */
@@ -182,10 +171,6 @@ ExpansionPanelSummary.propTypes = {
    * @ignore
    */
   onBlur: PropTypes.func,
-  /**
-   * @ignore
-   */
-  onChange: PropTypes.func,
   /**
    * @ignore
    */

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

@@ -4,6 +4,7 @@ import { spy } from 'sinon';
 import { createMount, getClasses } from '@material-ui/core/test-utils';
 import describeConformance from '../test-utils/describeConformance';
 import { createClientRender, fireEvent } from 'test/utils/createClientRender';
+import ExpansionPanel from '../ExpansionPanel';
 import ExpansionPanelSummary from './ExpansionPanelSummary';
 import ButtonBase from '../ButtonBase';
 
@@ -13,6 +14,7 @@ describe('<ExpansionPanelSummary />', () => {
   const render = createClientRender({ strict: true });
 
   before(() => {
+    // requires mocking the TransitionComponent of `ExpansionPanel`
     mount = createMount({ strict: true });
     classes = getClasses(<ExpansionPanelSummary />);
   });
@@ -33,13 +35,21 @@ describe('<ExpansionPanelSummary />', () => {
   });
 
   it('when disabled should have disabled class', () => {
-    const { getByRole } = render(<ExpansionPanelSummary disabled />);
+    const { getByRole } = render(
+      <ExpansionPanel disabled TransitionComponent={({ children }) => children}>
+        <ExpansionPanelSummary />
+      </ExpansionPanel>,
+    );
 
     expect(getByRole('button')).to.have.class(classes.disabled);
   });
 
   it('when expanded adds the expanded class to the button and expandIcon', () => {
-    const { container, getByRole } = render(<ExpansionPanelSummary expanded expandIcon="expand" />);
+    const { container, getByRole } = render(
+      <ExpansionPanel expanded TransitionComponent={({ children }) => children}>
+        <ExpansionPanelSummary expandIcon="expand" />
+      </ExpansionPanel>,
+    );
 
     const button = getByRole('button');
     expect(button).to.have.class(classes.expanded);
@@ -93,9 +103,13 @@ describe('<ExpansionPanelSummary />', () => {
     expect(handleClick.callCount).to.equal(1);
   });
 
-  it('calls onChange when clicking', () => {
+  it('fires onChange of the ExpansionPanel if clicked', () => {
     const handleChange = spy();
-    const { getByRole } = render(<ExpansionPanelSummary onChange={handleChange} />);
+    const { getByRole } = render(
+      <ExpansionPanel onChange={handleChange} TransitionComponent={({ children }) => children}>
+        <ExpansionPanelSummary />
+      </ExpansionPanel>,
+    );
 
     getByRole('button').click();