Add test for dragging-and-dropping html

test/e2e/specs/editor/blocks/image.spec.js

@@ -624,6 +624,66 @@ test.describe( 'Image', () => {
 			).toBe( new URL( page.url() ).host );
 		}, 'should replace the original image with the second image' ).toPass();
 	} );
+
+	test( 'should allow dragging and dropping HTML to media placeholder', async ( {
+		page,
+		editor,
+	} ) => {
+		await editor.insertBlock( { name: 'core/image' } );
+		const imageBlock = page.getByRole( 'document', {
+			name: 'Block: Image',
+		} );
+
+		const html = `
+			<figure>
+				<img src="https://live.staticflickr.com/3894/14962688165_04759a8b03_b.jpg" alt="Cat">
+				<figcaption>"Cat" by tomhouslay is licensed under <a href="https://creativecommons.org/licenses/by-nc/2.0/?ref=openverse">CC BY-NC 2.0</a>.</figcaption>
+			</figure>
+		`;
+
+		await page.evaluate( ( _html ) => {
+			const dummy = document.createElement( 'div' );
+			dummy.style.width = '10px';
+			dummy.style.height = '10px';
+			dummy.style.zIndex = 99999;
+			dummy.style.position = 'fixed';
+			dummy.style.top = 0;
+			dummy.style.left = 0;
+			dummy.draggable = 'true';
+			dummy.addEventListener( 'dragstart', ( event ) => {
+				event.dataTransfer.setData( 'text/html', _html );
+				setTimeout( () => {
+					dummy.remove();
+				}, 0 );
+			} );
+			document.body.appendChild( dummy );
+		}, html );
+
+		await page.mouse.move( 0, 0 );
+		await page.mouse.down();
+		await imageBlock.hover();
+		await page.mouse.up();
+
+		const host = new URL( page.url() ).host;
+
+		await expect.poll( editor.getBlocks ).toMatchObject( [
+			{
+				name: 'core/image',
+				attributes: {
+					link: expect.stringContaining( host ),
+					url: expect.stringContaining( host ),
+					id: expect.any( Number ),
+					alt: 'Cat',
+					caption: `"Cat" by tomhouslay is licensed under <a href="https://creativecommons.org/licenses/by-nc/2.0/?ref=openverse">CC BY-NC 2.0</a>.`,
+				},
+			},
+		] );
+		const url = ( await editor.getBlocks() )[ 0 ].attributes.url;
+		await expect( imageBlock.getByRole( 'img' ) ).toHaveAttribute(
+			'src',
+			url
+		);
+	} );
 } );
 
 class ImageBlockUtils {