Rich text: fix internal paste across multiline and single line instances

packages/block-editor/src/components/rich-text/use-paste-handler.js

@@ -21,6 +21,25 @@ import { filePasteHandler } from './file-paste-handler';
 import { addActiveFormats, isShortcode } from './utils';
 import { splitValue } from './split-value';
 
+/** @typedef {import('@wordpress/rich-text').RichTextValue} RichTextValue */
+
+/**
+ * Replaces line separators with line breaks if not multiline.
+ * Replaces line breaks with line separators if multiline.
+ *
+ * @param {RichTextValue} value       Value to adjust.
+ * @param {boolean}       isMultiline Wether to adjust to multiline or not.
+ *
+ * @return {RichTextValue} Adjusted value.
+ */
+function adjustLines( value, isMultiline ) {
+	if ( isMultiline ) {
+		return replace( value, /\n+/g, LINE_SEPARATOR );
+	}
+
+	return replace( value, new RegExp( LINE_SEPARATOR, 'g' ), '\n' );
+}
+
 export function usePasteHandler( props ) {
 	const propsRef = useRef( props );
 	propsRef.current = props;
@@ -110,13 +129,19 @@ export function usePasteHandler( props ) {
 			// without filtering the data. The filters are only meant for externally
 			// pasted content and remove inline styles.
 			if ( isInternal ) {
-				const pastedValue = create( {
+				const pastedMultilineTag =
+					clipboardData.getData( 'rich-text-multi-line-tag' ) ||
+					undefined;
+				let pastedValue = create( {
 					html,
-					multilineTag,
+					multilineTag: pastedMultilineTag,
 					multilineWrapperTags:
-						multilineTag === 'li' ? [ 'ul', 'ol' ] : undefined,
+						pastedMultilineTag === 'li'
+							? [ 'ul', 'ol' ]
+							: undefined,
 					preserveWhiteSpace,
 				} );
+				pastedValue = adjustLines( pastedValue, !! multilineTag );
 				addActiveFormats( pastedValue, value.activeFormats );
 				onChange( insert( value, pastedValue ) );
 				return;
@@ -190,18 +215,11 @@ export function usePasteHandler( props ) {
 			if ( typeof content === 'string' ) {
 				let valueToInsert = create( { html: content } );
 
-				addActiveFormats( valueToInsert, value.activeFormats );
-
 				// If the content should be multiline, we should process text
 				// separated by a line break as separate lines.
-				if ( multilineTag ) {
-					valueToInsert = replace(
-						valueToInsert,
-						/\n+/g,
-						LINE_SEPARATOR
-					);
-				}
+				valueToInsert = adjustLines( valueToInsert, !! multilineTag );
 
+				addActiveFormats( valueToInsert, value.activeFormats );
 				onChange( insert( value, valueToInsert ) );
 			} else if ( content.length > 0 ) {
 				if ( onReplace && isEmpty( value ) ) {

packages/e2e-tests/specs/editor/various/__snapshots__/rich-text.test.js.snap

@@ -100,6 +100,26 @@ exports[`RichText should only mutate text data on input 1`] = `
 <!-- /wp:paragraph -->"
 `;
 
+exports[`RichText should paste list contents into paragraph 1`] = `
+"<!-- wp:list -->
+<ul><li>1<ul><li>2</li></ul></li></ul>
+<!-- /wp:list -->
+
+<!-- wp:paragraph -->
+<p>1<br>2</p>
+<!-- /wp:paragraph -->"
+`;
+
+exports[`RichText should paste paragraph contents into list 1`] = `
+"<!-- wp:paragraph -->
+<p>1<br>2</p>
+<!-- /wp:paragraph -->
+
+<!-- wp:list -->
+<ul><li>1</li><li>2</li></ul>
+<!-- /wp:list -->"
+`;
+
 exports[`RichText should preserve internal formatting 1`] = `
 "<!-- wp:paragraph -->
 <p><mark style=\\"background-color:rgba(0, 0, 0, 0)\\" class=\\"has-inline-color has-cyan-bluish-gray-color\\">1</mark></p>

packages/e2e-tests/specs/editor/various/rich-text.test.js

@@ -410,7 +410,7 @@ describe( 'RichText', () => {
 		// Copy the colored text.
 		await pressKeyWithModifier( 'primary', 'c' );
 
-		// Collapsed the selection to the end.
+		// Collapse the selection to the end.
 		await page.keyboard.press( 'ArrowRight' );
 
 		// Create a new paragraph.
@@ -422,6 +422,56 @@ describe( 'RichText', () => {
 		expect( await getEditedPostContent() ).toMatchSnapshot();
 	} );
 
+	it( 'should paste paragraph contents into list', async () => {
+		await clickBlockAppender();
+
+		// Create two lines of text in a paragraph.
+		await page.keyboard.type( '1' );
+		await pressKeyWithModifier( 'shift', 'Enter' );
+		await page.keyboard.type( '2' );
+
+		// Select all and copy.
+		await pressKeyWithModifier( 'primary', 'a' );
+		await pressKeyWithModifier( 'primary', 'c' );
+
+		// Collapse the selection to the end.
+		await page.keyboard.press( 'ArrowRight' );
+
+		// Create a list.
+		await page.keyboard.press( 'Enter' );
+		await page.keyboard.type( '* ' );
+
+		// Paste paragraph contents.
+		await pressKeyWithModifier( 'primary', 'v' );
+
+		expect( await getEditedPostContent() ).toMatchSnapshot();
+	} );
+
+	it( 'should paste list contents into paragraph', async () => {
+		await clickBlockAppender();
+
+		// Create an indented list of two lines.
+		await page.keyboard.type( '* 1' );
+		await page.keyboard.press( 'Enter' );
+		await page.keyboard.type( ' 2' );
+
+		// Select all and copy.
+		await pressKeyWithModifier( 'primary', 'a' );
+		await pressKeyWithModifier( 'primary', 'c' );
+
+		// Collapse the selection to the end.
+		await page.keyboard.press( 'ArrowRight' );
+
+		// Create a paragraph.
+		await page.keyboard.press( 'Enter' );
+		await page.keyboard.press( 'Enter' );
+
+		// Paste paragraph contents.
+		await pressKeyWithModifier( 'primary', 'v' );
+
+		expect( await getEditedPostContent() ).toMatchSnapshot();
+	} );
+
 	it( 'should navigate arround emoji', async () => {
 		await clickBlockAppender();
 		await page.keyboard.type( '🍓' );

packages/rich-text/src/component/use-copy-handler.js

@@ -39,6 +39,10 @@ export function useCopyHandler( props ) {
 			event.clipboardData.setData( 'text/plain', plainText );
 			event.clipboardData.setData( 'text/html', html );
 			event.clipboardData.setData( 'rich-text', 'true' );
+			event.clipboardData.setData(
+				'rich-text-multi-line-tag',
+				multilineTag || ''
+			);
 			event.preventDefault();
 		}