Improved the docs and adjusted to changes in engine (Selection API).

src/deletecommand.js

@@ -120,8 +120,8 @@ export default class DeleteCommand extends Command {
 	 * we want to replace the entire content with a paragraph if:
 	 *
 	 * * the current limit element is empty,
-	 * * the paragraph is allowed in the common ancestor,
-	 * * other paragraph does not occur in the editor.
+	 * * the paragraph is allowed in the limit element,
+	 * * other empty paragraph does not occur in the limit element.
 	 *
 	 * See https://github.com/ckeditor/ckeditor5-typing/issues/61.
 	 *
@@ -138,9 +138,10 @@ export default class DeleteCommand extends Command {
 		const document = this.editor.document;
 		const selection = document.selection;
 		const limitElement = document.schema.getLimitElement( selection );
+
 		// If a collapsed selection contains the whole content it means that the content is empty
 		// (from the user perspective).
-		const limitElementIsEmpty = selection.isCollapsed && selection.isEntireContentSelected( limitElement );
+		const limitElementIsEmpty = selection.isCollapsed && selection.containsEntireContent( limitElement );
 
 		if ( !limitElementIsEmpty ) {
 			return false;
@@ -150,8 +151,10 @@ export default class DeleteCommand extends Command {
 			return false;
 		}
 
-		// Does nothing if editor already contains an empty paragraph.
-		if ( selection.getFirstRange().getCommonAncestor().name === 'paragraph' ) {
+		const limitElementFirstChild = limitElement.getChild( 0 );
+
+		// Does nothing if limit element already contains an empty paragraph.
+		if ( limitElementFirstChild && limitElementFirstChild.name === 'paragraph' ) {
 			return false;
 		}
 

tests/deletecommand.js

@@ -147,7 +147,7 @@ describe( 'DeleteCommand', () => {
 
 			editor.execute( 'delete' );
 
-			expect( getData( doc, { selection: true } ) ).to.equal( '<paragraph>[]</paragraph>' );
+			expect( getData( doc ) ).to.equal( '<paragraph>[]</paragraph>' );
 		} );
 
 		it( 'leaves an empty paragraph after removing the whole content inside limit element', () => {
@@ -157,24 +157,40 @@ describe( 'DeleteCommand', () => {
 
 			setData( doc,
 				'<heading1>Foo</heading1>' +
-				'<section>' +
-				'<heading1>[Header 1</heading1>' +
-				'<paragraph>Some text.]</paragraph>' +
-				'</section>' +
+					'<section>' +
+						'<heading1>[Header 1</heading1>' +
+						'<paragraph>Some text.]</paragraph>' +
+					'</section>' +
 				'<paragraph>Bar.</paragraph>'
 			);
 
 			editor.execute( 'delete' );
 
-			expect( getData( doc, { selection: true } ) ).to.equal(
+			expect( getData( doc ) ).to.equal(
 				'<heading1>Foo</heading1>' +
 				'<section>' +
-				'<paragraph>[]</paragraph>' +
+					'<paragraph>[]</paragraph>' +
 				'</section>' +
 				'<paragraph>Bar.</paragraph>'
 			);
 		} );
 
+		it( 'leaves an empty paragraph after removing another paragraph from block element', () => {
+			doc.schema.registerItem( 'section', '$block' );
+			doc.schema.registerItem( 'blockQuote', '$block' );
+			doc.schema.limits.add( 'section' );
+			doc.schema.allow( { name: 'section', inside: '$root' } );
+			doc.schema.allow( { name: 'paragraph', inside: 'section' } );
+			doc.schema.allow( { name: 'blockQuote', inside: 'section' } );
+			doc.schema.allow( { name: 'paragraph', inside: 'blockQuote' } );
+
+			setData( doc, '<section><blockQuote><paragraph>[]</paragraph></blockQuote></section>' );
+
+			editor.execute( 'delete' );
+
+			expect( getData( doc ) ).to.equal( '<section><paragraph>[]</paragraph></section>' );
+		} );
+
 		it( 'leaves an empty paragraph after removing the whole content when root element was not added as Schema.limits', () => {
 			doc.schema.limits.delete( '$root' );
 
@@ -190,7 +206,7 @@ describe( 'DeleteCommand', () => {
 
 			editor.execute( 'delete' );
 
-			expect( getData( doc, { selection: true } ) ).to.equal( '<paragraph>[]</paragraph>' );
+			expect( getData( doc ) ).to.equal( '<paragraph>[]</paragraph>' );
 		} );
 
 		it( 'does not replace an element when Backspace or Delete key is held', () => {
@@ -200,17 +216,17 @@ describe( 'DeleteCommand', () => {
 				editor.execute( 'delete', { sequence } );
 			}
 
-			expect( getData( doc, { selection: true } ) ).to.equal( '<heading1>[]</heading1>' );
+			expect( getData( doc ) ).to.equal( '<heading1>[]</heading1>' );
 		} );
 
-		it( 'does not replace an element if a paragraph is a common ancestor', () => {
+		it( 'does not replace with paragraph in another paragraph already occurs in limit element', () => {
 			setData( doc, '<paragraph>[]</paragraph>' );
 
-			const element = doc.selection.getFirstRange().getCommonAncestor();
+			const element = doc.getRoot().getNodeByPath( [ 0 ] );
 
 			editor.execute( 'delete' );
 
-			expect( element ).is.equal( doc.selection.getFirstRange().getCommonAncestor() );
+			expect( element ).is.equal( doc.getRoot().getNodeByPath( [ 0 ] ) );
 		} );
 
 		it( 'does not replace an element if a paragraph is not allowed in current position', () => {
@@ -221,7 +237,7 @@ describe( 'DeleteCommand', () => {
 			editor.execute( 'delete' );
 
 			// Returned data: '[]' instead of the heading element.
-			expect( getData( doc, { selection: true } ) ).to.equal( '<heading1>[]</heading1>' );
+			expect( getData( doc ) ).to.equal( '<heading1>[]</heading1>' );
 		} );
 	} );
 } );