Implemented the Range#getContainedElement() method.

src/model/range.js

@@ -501,6 +501,27 @@ export default class Range {
 		return this.start.getCommonAncestor( this.end );
 	}
 
+	/**
+	 * Returns an element contained by a range. The element will be returned when it is the **only** node
+	 * within the range and **fully–contained** at the same time.
+	 *
+	 * @returns {module:engine/model/element~Element|null}
+	 */
+	getContainedElement() {
+		if ( this.isCollapsed ) {
+			return null;
+		}
+
+		const nodeAfterStart = this.start.nodeAfter;
+		const nodeBeforeEnd = this.end.nodeBefore;
+
+		if ( nodeAfterStart && nodeAfterStart.is( 'element' ) && nodeAfterStart === nodeBeforeEnd ) {
+			return nodeAfterStart;
+		}
+
+		return null;
+	}
+
 	/**
 	 * Converts `Range` to plain object and returns it.
 	 *

tests/model/range.js

@@ -1351,6 +1351,47 @@ describe( 'Range', () => {
 		} );
 	} );
 
+	describe( 'getContainerElement()', () => {
+		beforeEach( () => {
+			prepareRichRoot( root );
+		} );
+
+		it( 'should return an element when it is fully contained by the range', () => {
+			// <div><h>first</h><p>lorem ipsum</p></div>[<p>foo</p>]<p>bar</p><div><h>second</h><p>lorem</p></div>
+			const range = new Range( new Position( root, [ 1 ] ), new Position( root, [ 2 ] ) );
+
+			expect( range.getContainedElement() ).to.equal( root.getNodeByPath( [ 1 ] ) );
+		} );
+
+		it( 'should return "null" if the range is collapsed', () => {
+			// <div><h>first</h><p>lorem ipsum</p></div>[]<p>foo</p><p>bar</p><div><h>second</h><p>lorem</p></div>
+			const range = new Range( new Position( root, [ 1 ] ) );
+
+			expect( range.getContainedElement() ).to.be.null;
+		} );
+
+		it( 'should return "null" if it contains 2+ elements', () => {
+			// <div><h>first</h><p>lorem ipsum</p></div>[<p>foo</p><p>bar</p>]<div><h>second</h><p>lorem</p></div>
+			const range = new Range( new Position( root, [ 1 ] ), new Position( root, [ 3 ] ) );
+
+			expect( range.getContainedElement() ).to.be.null;
+		} );
+
+		it( 'should return "null" if it contains an element and some other nodes', () => {
+			// <div><h>first</h><p>lorem ipsum</p></div>[<p>foo</p><p>ba]r</p><div><h>second</h><p>lorem</p></div>
+			const range = new Range( new Position( root, [ 1 ] ), new Position( root, [ 2, 2 ] ) );
+
+			expect( range.getContainedElement() ).to.be.null;
+		} );
+
+		it( 'should return "null" if it fully contains a node but the node is not an element', () => {
+			// <div><h>first</h><p>lorem ipsum</p></div><p>foo</p><p>[bar]</p><div><h>second</h><p>lorem</p></div>
+			const range = new Range( new Position( root, [ 2, 0 ] ), new Position( root, [ 2, 3 ] ) );
+
+			expect( range.getContainedElement() ).to.be.null;
+		} );
+	} );
+
 	function mapNodesToNames( nodes ) {
 		return nodes.map( node => {
 			return ( node instanceof Element ) ? 'E:' + node.name : 'T:' + node.data;