[RNMobile] Add integration tests to cover Drag & Drop functionality

packages/block-editor/src/components/block-draggable/draggable-chip.native.js

@@ -41,7 +41,7 @@ export default function BlockDraggableChip( { icon } ) {
 	);
 
 	return (
-		<View style={ [ containerStyle, shadowStyle ] }>
+		<View style={ [ containerStyle, shadowStyle ] } testID="draggable-chip">
 			<BlockIcon icon={ dragHandle } />
 			{ icon && <BlockIcon icon={ icon } /> }
 		</View>

packages/block-editor/src/components/block-draggable/index.native.js

@@ -270,6 +270,7 @@ const BlockDraggableWrapper = ( { children, isRTL } ) => {
 				onDragStart={ startDragging }
 				onDragOver={ updateDragging }
 				onDragEnd={ stopDragging }
+				testID="block-draggable-wrapper"
 			>
 				{ children( { onScroll: scrollHandler } ) }
 			</Draggable>
@@ -302,6 +303,7 @@ const BlockDraggableWrapper = ( { children, isRTL } ) => {
  * @param {string}      props.clientId           Client id of the block.
  * @param {string}      [props.draggingClientId] Client id to use for dragging. If not defined, the value from `clientId` will be used.
  * @param {boolean}     [props.enabled]          Enables the draggable trigger.
+ * @param {string}      [props.testID]           Id used for querying the long-press gesture handler in tests.
  *
  * @return {Function} Render function which includes the parameter `isDraggable` to determine if the block can be dragged.
  */
@@ -310,6 +312,7 @@ const BlockDraggable = ( {
 	children,
 	draggingClientId,
 	enabled = true,
+	testID,
 } ) => {
 	const wasBeingDragged = useRef( false );
 	const [ isEditingText, setIsEditingText ] = useState( false );
@@ -446,6 +449,7 @@ const BlockDraggable = ( {
 				android: DEFAULT_LONG_PRESS_MIN_DURATION,
 			} ) }
 			onLongPress={ onLongPressDraggable }
+			testID={ testID }
 		>
 			<Animated.View style={ wrapperStyles }>
 				{ children( { isDraggable: true } ) }

packages/block-editor/src/components/block-draggable/test/__snapshots__/index.native.js.snap

@@ -0,0 +1,73 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`BlockDraggable moves blocks: Initial order 1`] = `
+"<!-- wp:paragraph -->
+<p>This is a paragraph.</p>
+<!-- /wp:paragraph -->
+
+<!-- wp:image {\\"sizeSlug\\":\\"large\\"} -->
+<figure class=\\"wp-block-image size-large\\"><img src=\\"https://cldup.com/cXyG__fTLN.jpg\\" alt=\\"\\"/></figure>
+<!-- /wp:image -->
+
+<!-- wp:spacer -->
+<div style=\\"height:100px\\" aria-hidden=\\"true\\" class=\\"wp-block-spacer\\"></div>
+<!-- /wp:spacer -->
+
+<!-- wp:gallery {\\"linkTo\\":\\"none\\"} -->
+<figure class=\\"wp-block-gallery has-nested-images columns-default is-cropped\\"><!-- wp:image {\\"sizeSlug\\":\\"large\\",\\"linkDestination\\":\\"none\\"} -->
+<figure class=\\"wp-block-image size-large\\"><img src=\\"https://cldup.com/cXyG__fTLN.jpg\\" alt=\\"\\"/></figure>
+<!-- /wp:image -->
+
+<!-- wp:image {\\"sizeSlug\\":\\"large\\",\\"linkDestination\\":\\"none\\"} -->
+<figure class=\\"wp-block-image size-large\\"><img src=\\"https://cldup.com/cXyG__fTLN.jpg\\" alt=\\"\\"/></figure>
+<!-- /wp:image --></figure>
+<!-- /wp:gallery -->"
+`;
+
+exports[`BlockDraggable moves blocks: Paragraph block moved from first to second position 1`] = `
+"<!-- wp:image {\\"sizeSlug\\":\\"large\\"} -->
+<figure class=\\"wp-block-image size-large\\"><img src=\\"https://cldup.com/cXyG__fTLN.jpg\\" alt=\\"\\"/></figure>
+<!-- /wp:image -->
+
+<!-- wp:paragraph -->
+<p>This is a paragraph.</p>
+<!-- /wp:paragraph -->
+
+<!-- wp:spacer -->
+<div style=\\"height:100px\\" aria-hidden=\\"true\\" class=\\"wp-block-spacer\\"></div>
+<!-- /wp:spacer -->
+
+<!-- wp:gallery {\\"linkTo\\":\\"none\\"} -->
+<figure class=\\"wp-block-gallery has-nested-images columns-default is-cropped\\"><!-- wp:image {\\"sizeSlug\\":\\"large\\",\\"linkDestination\\":\\"none\\"} -->
+<figure class=\\"wp-block-image size-large\\"><img src=\\"https://cldup.com/cXyG__fTLN.jpg\\" alt=\\"\\"/></figure>
+<!-- /wp:image -->
+
+<!-- wp:image {\\"sizeSlug\\":\\"large\\",\\"linkDestination\\":\\"none\\"} -->
+<figure class=\\"wp-block-image size-large\\"><img src=\\"https://cldup.com/cXyG__fTLN.jpg\\" alt=\\"\\"/></figure>
+<!-- /wp:image --></figure>
+<!-- /wp:gallery -->"
+`;
+
+exports[`BlockDraggable moves blocks: Spacer block moved from third to first position 1`] = `
+"<!-- wp:spacer -->
+<div style=\\"height:100px\\" aria-hidden=\\"true\\" class=\\"wp-block-spacer\\"></div>
+<!-- /wp:spacer -->
+
+<!-- wp:image {\\"sizeSlug\\":\\"large\\"} -->
+<figure class=\\"wp-block-image size-large\\"><img src=\\"https://cldup.com/cXyG__fTLN.jpg\\" alt=\\"\\"/></figure>
+<!-- /wp:image -->
+
+<!-- wp:paragraph -->
+<p>This is a paragraph.</p>
+<!-- /wp:paragraph -->
+
+<!-- wp:gallery {\\"linkTo\\":\\"none\\"} -->
+<figure class=\\"wp-block-gallery has-nested-images columns-default is-cropped\\"><!-- wp:image {\\"sizeSlug\\":\\"large\\",\\"linkDestination\\":\\"none\\"} -->
+<figure class=\\"wp-block-image size-large\\"><img src=\\"https://cldup.com/cXyG__fTLN.jpg\\" alt=\\"\\"/></figure>
+<!-- /wp:image -->
+
+<!-- wp:image {\\"sizeSlug\\":\\"large\\",\\"linkDestination\\":\\"none\\"} -->
+<figure class=\\"wp-block-image size-large\\"><img src=\\"https://cldup.com/cXyG__fTLN.jpg\\" alt=\\"\\"/></figure>
+<!-- /wp:image --></figure>
+<!-- /wp:gallery -->"
+`;

packages/block-editor/src/components/block-draggable/test/helpers.native.js

@@ -0,0 +1,183 @@
+/**
+ * External dependencies
+ */
+import {
+	act,
+	fireEvent,
+	initializeEditor,
+	waitForStoreResolvers,
+	within,
+	advanceAnimationByFrame,
+} from 'test/helpers';
+import { fireGestureHandler } from 'react-native-gesture-handler/jest-utils';
+import { State } from 'react-native-gesture-handler';
+
+// Touch event type constants have been extracted from original source code, as they are not exported in the package.
+// Reference: https://github.com/software-mansion/react-native-gesture-handler/blob/90895e5f38616a6be256fceec6c6a391cd9ad7c7/src/TouchEventType.ts
+export const TouchEventType = {
+	UNDETERMINED: 0,
+	TOUCHES_DOWN: 1,
+	TOUCHES_MOVE: 2,
+	TOUCHES_UP: 3,
+	TOUCHES_CANCELLED: 4,
+};
+
+const DEFAULT_TOUCH_EVENTS = [
+	{
+		id: 1,
+		eventType: TouchEventType.TOUCHES_DOWN,
+		x: 0,
+		y: 0,
+	},
+];
+
+/**
+ * @typedef  {Object} WPBlockWithLayout
+ * @property {string} name          Name of the block (e.g. Paragraph).
+ * @property {string} html          HTML content.
+ * @property {Object} layout        Layout data.
+ * @property {Object} layout.x      X position.
+ * @property {Object} layout.y      Y position.
+ * @property {Object} layout.width  Width.
+ * @property {Object} layout.height Height.
+ */
+
+/**
+ * Initialize the editor with an array of blocks that include their HTML and layout.
+ *
+ * @param {WPBlockWithLayout[]} blocks Initial blocks.
+ *
+ * @return {import('@testing-library/react-native').RenderAPI} The Testing Library screen.
+ */
+export const initializeWithBlocksLayouts = async ( blocks ) => {
+	const initialHtml = blocks.map( ( block ) => block.html ).join( '\n' );
+
+	const screen = await initializeEditor( { initialHtml } );
+	const { getByA11yLabel } = screen;
+
+	const waitPromises = [];
+	blocks.forEach( ( block, index ) => {
+		const a11yLabel = new RegExp(
+			`${ block.name } Block\\. Row ${ index + 1 }`
+		);
+		const element = getByA11yLabel( a11yLabel );
+		// "onLayout" event will populate the blocks layouts data.
+		fireEvent( element, 'layout', {
+			nativeEvent: { layout: block.layout },
+		} );
+		if ( block.nestedBlocks ) {
+			// Nested blocks are rendered via the FlatList of the inner block list.
+			// In order to render the items of a FlatList, it's required to trigger the
+			// "onLayout" event. Additionally, the call is wrapped over "waitForStoreResolvers"
+			// because the nested blocks might make API requests (e.g. the Gallery block).
+			waitPromises.push(
+				waitForStoreResolvers( () =>
+					fireEvent(
+						within( element ).getByTestId( 'block-list-wrapper' ),
+						'layout',
+						{
+							nativeEvent: {
+								layout: {
+									width: block.layout.width,
+									height: block.layout.height,
+								},
+							},
+						}
+					)
+				)
+			);
+
+			block.nestedBlocks.forEach( ( nestedBlock, nestedIndex ) => {
+				const nestedA11yLabel = new RegExp(
+					`${ nestedBlock.name } Block\\. Row ${ nestedIndex + 1 }`
+				);
+				fireEvent(
+					within( element ).getByA11yLabel( nestedA11yLabel ),
+					'layout',
+					{
+						nativeEvent: { layout: nestedBlock.layout },
+					}
+				);
+			} );
+		}
+	} );
+	await Promise.all( waitPromises );
+
+	return screen;
+};
+
+/**
+ * Fires long-press gesture event on a block.
+ *
+ * @param {import('react-test-renderer').ReactTestInstance} block                  Block test instance.
+ * @param {string}                                          testID                 Id for querying the draggable trigger element.
+ * @param {Object}                                          [options]              Configuration options for the gesture event.
+ * @param {boolean}                                         [options.failed]       Determines if the gesture should fail.
+ * @param {number}                                          [options.triggerIndex] In case there are multiple draggable triggers, this specifies the index to use.
+ */
+export const fireLongPress = (
+	block,
+	testID,
+	{ failed = false, triggerIndex } = {}
+) => {
+	const draggableTrigger =
+		typeof triggerIndex !== 'undefined'
+			? within( block ).getAllByTestId( testID )[ triggerIndex ]
+			: within( block ).getByTestId( testID );
+	if ( failed ) {
+		fireGestureHandler( draggableTrigger, [ { state: State.FAILED } ] );
+	} else {
+		fireGestureHandler( draggableTrigger, [
+			{ oldState: State.BEGAN, state: State.ACTIVE },
+			{ state: State.ACTIVE },
+			{ state: State.END },
+		] );
+	}
+	// Advance timers one frame to ensure that shared values
+	// are updated and trigger animation reactions.
+	act( () => advanceAnimationByFrame( 1 ) );
+};
+
+/**
+ * Fires pan gesture event on a BlockDraggable component.
+ *
+ * @param {import('react-test-renderer').ReactTestInstance} blockDraggable BlockDraggable test instance.
+ * @param {Object}                                          [touchEvents]  Array of touch events to dispatch on the pan gesture.
+ */
+export const firePanGesture = (
+	blockDraggable,
+	touchEvents = DEFAULT_TOUCH_EVENTS
+) => {
+	const gestureTouchEvents = touchEvents.map(
+		( { eventType, ...touchEvent } ) => ( {
+			allTouches: [ touchEvent ],
+			eventType,
+		} )
+	);
+	fireGestureHandler( blockDraggable, [
+		// TOUCHES_DOWN event is only received on ACTIVE state, so we have to fire it manually.
+		{ oldState: State.BEGAN, state: State.ACTIVE },
+		...gestureTouchEvents,
+		{ state: State.END },
+	] );
+	// Advance timers one frame to ensure that shared values
+	// are updated and trigger animation reactions.
+	act( () => advanceAnimationByFrame( 1 ) );
+};
+
+/**
+ * Gets the draggable chip element.
+ *
+ * @param {import('@testing-library/react-native').RenderAPI} screen The Testing Library screen.
+ *
+ * @return {import('react-test-renderer').ReactTestInstance} Draggable chip test instance.
+ */
+export const getDraggableChip = ( { getByTestId } ) => {
+	let draggableChip;
+	try {
+		draggableChip = getByTestId( 'draggable-chip' );
+	} catch ( e ) {
+		// NOOP.
+	}
+	return draggableChip;
+};