From 39d508670d7a9ae42614ed5f658b43d20787aee6 Mon Sep 17 00:00:00 2001
From: Janvo Aldred <scorpitar@gmail.com>
Date: Mon, 10 Aug 2020 06:25:25 +0000
Subject: [PATCH] Refactored PostTextEditor to use React Hook (#23897)

* Refactored PostTextEditor to use React Hook

* use useInstanceId hook instead of withInstanceId

* Replaced withSelect and withDispatch with useSelect and useDispatch

* Replaced withSelect and withDispatch with useSelect and useDispatch

* Remove external prop support

* Refactored edit function to onChange

* Removed onPersist function

Co-authored-by: Janvo Aldred <janvoaldred@hotmail.com>
---
 .../src/components/post-text-editor/index.js  | 124 +++++--------
 .../components/post-text-editor/test/index.js | 174 +++++++++++-------
 2 files changed, 158 insertions(+), 140 deletions(-)

diff --git a/packages/editor/src/components/post-text-editor/index.js b/packages/editor/src/components/post-text-editor/index.js
index d0e0626a75f162..eb8488332ee81a 100644
--- a/packages/editor/src/components/post-text-editor/index.js
+++ b/packages/editor/src/components/post-text-editor/index.js
@@ -7,31 +7,26 @@ import Textarea from 'react-autosize-textarea';
  * WordPress dependencies
  */
 import { __ } from '@wordpress/i18n';
-import { Component } from '@wordpress/element';
+import { useState } from '@wordpress/element';
 import { parse } from '@wordpress/blocks';
-import { withSelect, withDispatch } from '@wordpress/data';
-import { withInstanceId, compose } from '@wordpress/compose';
+import { useDispatch, useSelect } from '@wordpress/data';
+import { useInstanceId } from '@wordpress/compose';
 import { VisuallyHidden } from '@wordpress/components';
 
-export class PostTextEditor extends Component {
-	constructor() {
-		super( ...arguments );
+export default function PostTextEditor() {
+	const postContent = useSelect(
+		( select ) => select( 'core/editor' ).getEditedPostContent(),
+		[]
+	);
 
-		this.edit = this.edit.bind( this );
-		this.stopEditing = this.stopEditing.bind( this );
+	const { editPost, resetEditorBlocks } = useDispatch( 'core/editor' );
 
-		this.state = {};
-	}
-
-	static getDerivedStateFromProps( props, state ) {
-		if ( state.isDirty ) {
-			return null;
-		}
+	const [ value, setValue ] = useState( postContent );
+	const [ isDirty, setIsDirty ] = useState( false );
+	const instanceId = useInstanceId( PostTextEditor );
 
-		return {
-			value: props.value,
-			isDirty: false,
-		};
+	if ( ! isDirty && value !== postContent ) {
+		setValue( postContent );
 	}
 
 	/**
@@ -45,68 +40,47 @@ export class PostTextEditor extends Component {
 	 *
 	 * @param {Event} event Change event.
 	 */
-	edit( event ) {
-		const value = event.target.value;
-		this.props.onChange( value );
-		this.setState( { value, isDirty: true } );
-	}
+	const onChange = ( event ) => {
+		const newValue = event.target.value;
+
+		editPost( { content: newValue } );
+
+		setValue( newValue );
+		setIsDirty( true );
+	};
 
 	/**
 	 * Function called when the user has completed their edits, responsible for
 	 * ensuring that changes, if made, are surfaced to the onPersist prop
 	 * callback and resetting dirty state.
 	 */
-	stopEditing() {
-		if ( this.state.isDirty ) {
-			this.props.onPersist( this.state.value );
-			this.setState( { isDirty: false } );
+	const stopEditing = () => {
+		if ( isDirty ) {
+			const blocks = parse( value );
+			resetEditorBlocks( blocks );
+
+			setIsDirty( false );
 		}
-	}
+	};
 
-	render() {
-		const { value } = this.state;
-		const { instanceId } = this.props;
-		return (
-			<>
-				<VisuallyHidden
-					as="label"
-					htmlFor={ `post-content-${ instanceId }` }
-				>
-					{ __( 'Type text or HTML' ) }
-				</VisuallyHidden>
-				<Textarea
-					autoComplete="off"
-					dir="auto"
-					value={ value }
-					onChange={ this.edit }
-					onBlur={ this.stopEditing }
-					className="editor-post-text-editor"
-					id={ `post-content-${ instanceId }` }
-					placeholder={ __( 'Start writing with text or HTML' ) }
-				/>
-			</>
-		);
-	}
+	return (
+		<>
+			<VisuallyHidden
+				as="label"
+				htmlFor={ `post-content-${ instanceId }` }
+			>
+				{ __( 'Type text or HTML' ) }
+			</VisuallyHidden>
+			<Textarea
+				autoComplete="off"
+				dir="auto"
+				value={ value }
+				onChange={ onChange }
+				onBlur={ stopEditing }
+				className="editor-post-text-editor"
+				id={ `post-content-${ instanceId }` }
+				placeholder={ __( 'Start writing with text or HTML' ) }
+			/>
+		</>
+	);
 }
-
-export default compose( [
-	withSelect( ( select ) => {
-		const { getEditedPostContent } = select( 'core/editor' );
-		return {
-			value: getEditedPostContent(),
-		};
-	} ),
-	withDispatch( ( dispatch ) => {
-		const { editPost, resetEditorBlocks } = dispatch( 'core/editor' );
-		return {
-			onChange( content ) {
-				editPost( { content } );
-			},
-			onPersist( content ) {
-				const blocks = parse( content );
-				resetEditorBlocks( blocks );
-			},
-		};
-	} ),
-	withInstanceId,
-] )( PostTextEditor );
diff --git a/packages/editor/src/components/post-text-editor/test/index.js b/packages/editor/src/components/post-text-editor/test/index.js
index 6ca88cacb78df8..d132c3b47cd79a 100644
--- a/packages/editor/src/components/post-text-editor/test/index.js
+++ b/packages/editor/src/components/post-text-editor/test/index.js
@@ -1,13 +1,18 @@
 /**
  * External dependencies
  */
-import { create } from 'react-test-renderer';
+import { act, create } from 'react-test-renderer';
 import Textarea from 'react-autosize-textarea';
 
+/**
+ * WordPress dependencies
+ */
+import { useSelect } from '@wordpress/data';
+
 /**
  * Internal dependencies
  */
-import { PostTextEditor } from '../';
+import PostTextEditor from '../';
 
 // "Downgrade" ReactAutosizeTextarea to a regular textarea. Assumes aligned
 // props interface.
@@ -15,92 +20,135 @@ jest.mock( 'react-autosize-textarea', () => ( props ) => (
 	<textarea { ...props } />
 ) );
 
+jest.mock( '@wordpress/data/src/components/use-select', () => {
+	// This allows us to tweak the returned value on each test
+	const mock = jest.fn();
+	return mock;
+} );
+
+let mockEditPost = jest.fn();
+let mockResetEditorBlocks = jest.fn();
+
+jest.mock( '@wordpress/data/src/components/use-dispatch', () => {
+	return {
+		useDispatch: () => ( {
+			editPost: mockEditPost,
+			resetEditorBlocks: mockResetEditorBlocks,
+		} ),
+	};
+} );
+
 describe( 'PostTextEditor', () => {
-	it( 'should render via the prop value', () => {
-		const wrapper = create( <PostTextEditor value="Hello World" /> );
+	beforeEach( () => {
+		useSelect.mockImplementation( () => 'Hello World' );
+
+		mockEditPost = jest.fn();
+		mockResetEditorBlocks = jest.fn();
+	} );
+
+	it( 'should render via the value from useSelect', () => {
+		let wrapper;
+
+		act( () => {
+			wrapper = create( <PostTextEditor /> );
+		} );
 
 		const textarea = wrapper.root.findByType( Textarea );
 		expect( textarea.props.value ).toBe( 'Hello World' );
 	} );
 
 	it( 'should render via the state value when edits made', () => {
-		const onChange = jest.fn();
-		const wrapper = create(
-			<PostTextEditor value="Hello World" onChange={ onChange } />
-		);
+		let wrapper;
+
+		act( () => {
+			wrapper = create( <PostTextEditor /> );
+		} );
 
 		const textarea = wrapper.root.findByType( Textarea );
-		textarea.props.onChange( { target: { value: 'Hello Chicken' } } );
+
+		act( () =>
+			textarea.props.onChange( { target: { value: 'Hello Chicken' } } )
+		);
 
 		expect( textarea.props.value ).toBe( 'Hello Chicken' );
-		expect( onChange ).toHaveBeenCalledWith( 'Hello Chicken' );
+		expect( mockEditPost ).toHaveBeenCalledWith( {
+			content: 'Hello Chicken',
+		} );
 	} );
 
 	it( 'should render via the state value when edits made, even if prop value changes', () => {
-		const onChange = jest.fn();
-		const wrapper = create(
-			<PostTextEditor value="Hello World" onChange={ onChange } />
-		);
+		let wrapper;
+
+		act( () => {
+			wrapper = create( <PostTextEditor /> );
+		} );
 
 		const textarea = wrapper.root.findByType( Textarea );
-		textarea.props.onChange( { target: { value: 'Hello Chicken' } } );
 
-		wrapper.update(
-			<PostTextEditor value="Goodbye World" onChange={ onChange } />
+		act( () =>
+			textarea.props.onChange( { target: { value: 'Hello Chicken' } } )
 		);
 
+		useSelect.mockImplementation( () => 'Goodbye World' );
+
+		act( () => {
+			wrapper.update( <PostTextEditor /> );
+		} );
+
 		expect( textarea.props.value ).toBe( 'Hello Chicken' );
-		expect( onChange ).toHaveBeenCalledWith( 'Hello Chicken' );
+		expect( mockEditPost ).toHaveBeenCalledWith( {
+			content: 'Hello Chicken',
+		} );
 	} );
 
 	it( 'should render via the state value when edits made, even if prop value changes and state value empty', () => {
-		const onChange = jest.fn();
-		const wrapper = create(
-			<PostTextEditor value="Hello World" onChange={ onChange } />
-		);
+		let wrapper;
+
+		act( () => {
+			wrapper = create( <PostTextEditor /> );
+		} );
 
 		const textarea = wrapper.root.findByType( Textarea );
-		textarea.props.onChange( { target: { value: '' } } );
+		act( () => textarea.props.onChange( { target: { value: '' } } ) );
 
-		wrapper.update(
-			<PostTextEditor value="Goodbye World" onChange={ onChange } />
-		);
+		useSelect.mockImplementation( () => 'Goodbye World' );
+
+		act( () => {
+			wrapper.update( <PostTextEditor /> );
+		} );
 
 		expect( textarea.props.value ).toBe( '' );
-		expect( onChange ).toHaveBeenCalledWith( '' );
+		expect( mockEditPost ).toHaveBeenCalledWith( {
+			content: '',
+		} );
 	} );
 
 	it( 'calls onPersist after changes made and user stops editing', () => {
-		const onPersist = jest.fn();
-		const wrapper = create(
-			<PostTextEditor
-				value="Hello World"
-				onChange={ () => {} }
-				onPersist={ onPersist }
-			/>
-		);
+		let wrapper;
+
+		act( () => {
+			wrapper = create( <PostTextEditor /> );
+		} );
 
 		const textarea = wrapper.root.findByType( Textarea );
-		textarea.props.onChange( { target: { value: '' } } );
-		textarea.props.onBlur();
 
-		expect( onPersist ).toHaveBeenCalledWith( '' );
+		act( () => textarea.props.onChange( { target: { value: '' } } ) );
+		act( () => textarea.props.onBlur() );
+
+		expect( mockResetEditorBlocks ).toHaveBeenCalledWith( [] );
 	} );
 
 	it( 'does not call onPersist after user stops editing without changes', () => {
-		const onPersist = jest.fn();
-		const wrapper = create(
-			<PostTextEditor
-				value="Hello World"
-				onChange={ () => {} }
-				onPersist={ onPersist }
-			/>
-		);
+		let wrapper;
+
+		act( () => {
+			wrapper = create( <PostTextEditor /> );
+		} );
 
 		const textarea = wrapper.root.findByType( Textarea );
-		textarea.props.onBlur();
+		act( () => textarea.props.onBlur() );
 
-		expect( onPersist ).not.toHaveBeenCalled();
+		expect( mockResetEditorBlocks ).not.toHaveBeenCalled();
 	} );
 
 	it( 'resets to prop value after user stops editing', () => {
@@ -108,26 +156,22 @@ describe( 'PostTextEditor', () => {
 		// parent renderer to pass the value as it had received onPersist. The
 		// test here is more an edge case to stress that it's intentionally
 		// differentiating between state and prop values.
-		const wrapper = create(
-			<PostTextEditor
-				value="Hello World"
-				onChange={ () => {} }
-				onPersist={ () => {} }
-			/>
-		);
+		let wrapper;
+
+		act( () => {
+			wrapper = create( <PostTextEditor /> );
+		} );
 
 		const textarea = wrapper.root.findByType( Textarea );
-		textarea.props.onChange( { target: { value: '' } } );
-
-		wrapper.update(
-			<PostTextEditor
-				value="Goodbye World"
-				onChange={ () => {} }
-				onPersist={ () => {} }
-			/>
-		);
+		act( () => textarea.props.onChange( { target: { value: '' } } ) );
+
+		useSelect.mockImplementation( () => 'Goodbye World' );
+
+		act( () => {
+			wrapper.update( <PostTextEditor /> );
+		} );
 
-		textarea.props.onBlur();
+		act( () => textarea.props.onBlur() );
 
 		expect( textarea.props.value ).toBe( 'Goodbye World' );
 	} );