Add tests for useDropZone

packages/compose/src/hooks/use-drop-zone/test/index.js

@@ -0,0 +1,63 @@
+/**
+ * External dependencies
+ */
+import { render, screen } from '@testing-library/react';
+
+/**
+ * WordPress dependencies
+ */
+import { useRef } from '@wordpress/element';
+
+/**
+ * Internal dependencies
+ */
+import useDropZone from '../';
+
+describe( 'useDropZone', () => {
+	const ComponentWithWrapperDropZone = () => {
+		const outerRef = useRef();
+		const dropZoneRef = useDropZone( {
+			dropZoneRef: outerRef,
+		} );
+
+		return (
+			<div role="main" ref={ outerRef }>
+				<div role="region" ref={ dropZoneRef }>
+					<div>Drop Zone</div>
+				</div>
+			</div>
+		);
+	};
+
+	const ComponentWithoutWrapperDropZone = () => {
+		const dropZoneRef = useDropZone( {} );
+
+		return (
+			<div role="main">
+				<div role="region" ref={ dropZoneRef }>
+					<div>Drop Zone</div>
+				</div>
+			</div>
+		);
+	};
+
+	it( 'will attach dropzone to outer wrapper', () => {
+		const { rerender } = render( <ComponentWithWrapperDropZone /> );
+		// Ensure `useEffect` has run.
+		rerender( <ComponentWithWrapperDropZone /> );
+
+		expect( screen.getByRole( 'main' ) ).toHaveAttribute(
+			'data-is-drop-zone'
+		);
+	} );
+
+	it( 'will attach dropzone to element with dropZoneRef attached', () => {
+		const { rerender } = render( <ComponentWithoutWrapperDropZone /> );
+		// Ensure `useEffect` has run.
+		rerender( <ComponentWithoutWrapperDropZone /> );
+
+		expect( screen.getByRole( 'region' ) ).toHaveAttribute(
+			'data-is-drop-zone'
+		);
+	} );
+} );