From 47a56b8a64af36588217e654121002702d919251 Mon Sep 17 00:00:00 2001
From: Ella <4710635+ellatrix@users.noreply.github.com>
Date: Fri, 31 May 2024 11:12:00 +0300
Subject: [PATCH] Writing flow: remove first empty paragraph on Backspace
 (#61889)

---
 .../src/components/block-list/block.js        | 48 ++++++++++++++-----
 .../specs/editor/various/writing-flow.spec.js | 31 ++++++++++++
 2 files changed, 68 insertions(+), 11 deletions(-)

diff --git a/packages/block-editor/src/components/block-list/block.js b/packages/block-editor/src/components/block-list/block.js
index 0220a9877eba28..030d08b42ce4dd 100644
--- a/packages/block-editor/src/components/block-list/block.js
+++ b/packages/block-editor/src/components/block-list/block.js
@@ -265,6 +265,7 @@ const applyWithDispatch = withDispatch( ( dispatch, ownProps, registry ) => {
 		__unstableMarkLastChangeAsPersistent,
 		moveBlocksToPosition,
 		removeBlock,
+		selectBlock,
 	} = dispatch( blockEditorStore );
 
 	// Do not add new properties here, use `useDispatch` instead to avoid
@@ -306,6 +307,28 @@ const applyWithDispatch = withDispatch( ( dispatch, ownProps, registry ) => {
 				canInsertBlockType,
 			} = registry.select( blockEditorStore );
 
+			function switchToDefaultOrRemove() {
+				const block = getBlock( clientId );
+				const defaultBlockName = getDefaultBlockName();
+				if ( getBlockName( clientId ) !== defaultBlockName ) {
+					const replacement = switchToBlockType(
+						block,
+						defaultBlockName
+					);
+					if ( replacement && replacement.length ) {
+						replaceBlocks( clientId, replacement );
+					}
+				} else if ( isUnmodifiedDefaultBlock( block ) ) {
+					const nextBlockClientId = getNextBlockClientId( clientId );
+					if ( nextBlockClientId ) {
+						registry.batch( () => {
+							removeBlock( clientId );
+							selectBlock( nextBlockClientId );
+						} );
+					}
+				}
+			}
+
 			/**
 			 * Moves the block with clientId up one level. If the block type
 			 * cannot be inserted at the new location, it will be attempted to
@@ -345,7 +368,16 @@ const applyWithDispatch = withDispatch( ( dispatch, ownProps, registry ) => {
 								getDefaultBlockName()
 							);
 
-							if ( replacement && replacement.length ) {
+							if (
+								replacement &&
+								replacement.length &&
+								replacement.every( ( block ) =>
+									canInsertBlockType(
+										block.name,
+										targetRootClientId
+									)
+								)
+							) {
 								insertBlocks(
 									replacement,
 									getBlockIndex( _clientId ),
@@ -353,6 +385,8 @@ const applyWithDispatch = withDispatch( ( dispatch, ownProps, registry ) => {
 									changeSelection
 								);
 								removeBlock( firstClientId, false );
+							} else {
+								switchToDefaultOrRemove();
 							}
 						}
 
@@ -463,16 +497,8 @@ const applyWithDispatch = withDispatch( ( dispatch, ownProps, registry ) => {
 					}
 
 					moveFirstItemUp( rootClientId );
-				} else if (
-					getBlockName( clientId ) !== getDefaultBlockName()
-				) {
-					const replacement = switchToBlockType(
-						getBlock( clientId ),
-						getDefaultBlockName()
-					);
-					if ( replacement && replacement.length ) {
-						replaceBlocks( clientId, replacement );
-					}
+				} else {
+					switchToDefaultOrRemove();
 				}
 			}
 		},
diff --git a/test/e2e/specs/editor/various/writing-flow.spec.js b/test/e2e/specs/editor/various/writing-flow.spec.js
index 2dee26255c103b..2eee3cad2b73ff 100644
--- a/test/e2e/specs/editor/various/writing-flow.spec.js
+++ b/test/e2e/specs/editor/various/writing-flow.spec.js
@@ -595,6 +595,37 @@ test.describe( 'Writing Flow (@firefox, @webkit)', () => {
 		] );
 	} );
 
+	test( 'should remove first empty paragraph on Backspace', async ( {
+		editor,
+		page,
+	} ) => {
+		await page.keyboard.press( 'Enter' );
+		await page.keyboard.press( 'Enter' );
+		await page.keyboard.type( '2' );
+		await page.keyboard.press( 'ArrowUp' );
+
+		// Ensure setup is correct.
+		expect( await editor.getBlocks() ).toMatchObject( [
+			{
+				name: 'core/paragraph',
+				attributes: { content: '' },
+			},
+			{
+				name: 'core/paragraph',
+				attributes: { content: '2' },
+			},
+		] );
+
+		await page.keyboard.press( 'Backspace' );
+
+		expect( await editor.getBlocks() ).toMatchObject( [
+			{
+				name: 'core/paragraph',
+				attributes: { content: '2' },
+			},
+		] );
+	} );
+
 	test( 'should merge paragraphs', async ( { editor, page } ) => {
 		await page.keyboard.press( 'Enter' );
 		await page.keyboard.type( '1' );