TreeGrid: Convert to TypeScript (#47516)

* TreeGridRow: Convert to TypeScript

* Add types for roving tab index

* Actually throw if context is undefined

* TreeGridItem: Add types

* TreeGridCell: Add types

* TreeGrid: Add types

* Fixup

* Convert stories

* Convert tests

* Exclude from tsconfig

* Improve prop description for `withoutGridItem`

* Simply focusable element type

* Remove unnecessary eslint-disable

* Tweak aria types

* Update readme

* Add changelog

* Change confusing story

* Shift all possible `Element`s to `HTMLElement`

packages/components/CHANGELOG.md

@@ -27,6 +27,7 @@
 -   `Button`: Convert to TypeScript ([#46997](https://github.com/WordPress/gutenberg/pull/46997)).
 -   `BoxControl`: Convert to TypeScript ([#47622](https://github.com/WordPress/gutenberg/pull/47622)).
 -   `QueryControls`: Convert to TypeScript ([#46721](https://github.com/WordPress/gutenberg/pull/46721)).
+-   `TreeGrid`: Convert to TypeScript ([#47516](https://github.com/WordPress/gutenberg/pull/47516)).
 -   `Notice`: refactor to TypeScript ([47118](https://github.com/WordPress/gutenberg/pull/47118)).
 
 ### Bug Fix

packages/components/src/tree-grid/README.md

@@ -10,7 +10,7 @@ This feature is still experimental. “Experimental” means this is an early im
 
 ## Development guidelines
 
-`TreeGrid`, `TreeGridRow`, and `TreeGridCell` are components used to create a tree hierarchy. They're not visually styled components, but instead help with adding keyboard navigation and roving tab index behaviors to tree grid structures.
+`TreeGrid`, `TreeGridRow`, and `TreeGridCell` are components used to create a tree hierarchy. They're not visually styled components, but instead help with adding keyboard navigation and roving tabindex behaviors to tree grid structures.
 
 A tree grid is a hierarchical 2 dimensional UI component, for example it could be used to implement a file system browser.
 
@@ -31,69 +31,36 @@ function TreeMenu() {
 			<TreeGridRow level={ 1 } positionInSet={ 1 } setSize={ 2 }>
 				<TreeGridCell>
 					{ ( props ) => (
-						<Button onClick={ onSelect } { ...props }>
-							Select
-						</Button>
+						<Button onClick={ onSelect } { ...props }>Select</Button>
 					) }
 				</TreeGridCell>
 				<TreeGridCell>
 					{ ( props ) => (
-						<Button onClick={ onMoveUp } { ...props }>
-							Move Up
-						</Button>
-					) }
-				</TreeGridCell>
-				<TreeGridCell>
-					{ ( props ) => (
-						<Button onClick={ onMoveDown } { ...props }>
-							Move Down
-						</Button>
+						<Button onClick={ onMove } { ...props }>Move</Button>
 					) }
 				</TreeGridCell>
 			</TreeGridRow>
 			<TreeGridRow level={ 1 } positionInSet={ 2 } setSize={ 2 }>
 				<TreeGridCell>
 					{ ( props ) => (
-						<Button onClick={ onSelect } { ...props }>
-							Select
-						</Button>
-					) }
-				</TreeGridCell>
-				<TreeGridCell>
-					{ ( props ) => (
-						<Button onClick={ onMoveUp } { ...props }>
-							Move Up
-						</Button>
+						<Button onClick={ onSelect } { ...props }>Select</Button>
 					) }
 				</TreeGridCell>
 				<TreeGridCell>
 					{ ( props ) => (
-						<Button onClick={ onMoveDown } { ...props }>
-							Move Down
-						</Button>
+						<Button onClick={ onMove } { ...props }>Move</Button>
 					) }
 				</TreeGridCell>
 			</TreeGridRow>
 			<TreeGridRow level={ 2 } positionInSet={ 1 } setSize={ 1 }>
 				<TreeGridCell>
 					{ ( props ) => (
-						<Button onClick={ onSelect } { ...props }>
-							Select
-						</Button>
-					) }
-				</TreeGridCell>
-				<TreeGridCell>
-					{ ( props ) => (
-						<Button onClick={ onMoveUp } { ...props }>
-							Move Up
-						</Button>
+						<Button onClick={ onSelect } { ...props }>Select</Button>
 					) }
 				</TreeGridCell>
 				<TreeGridCell>
 					{ ( props ) => (
-						<Button onClick={ onMoveDown } { ...props }>
-							Move Down
-						</Button>
+						<Button onClick={ onMove } { ...props }>Move</Button>
 					) }
 				</TreeGridCell>
 			</TreeGridRow>
@@ -112,27 +79,24 @@ Aside from the documented callback functions, any props specified will be passed
 
 `TreeGrid` should always have children.
 
-###### onFocusRow( event: Event, startRow: HTMLElement, destinationRow: HTMLElement )
+###### `onFocusRow`: `( event: KeyboardEvent, startRow: HTMLElement, destinationRow: HTMLElement ) => void`
 
 Callback that fires when focus is shifted from one row to another via the Up and Down keys. Callback is also fired on Home and End keys which move focus from the beginning row to the end row.
 The callback is passed the event, the start row element that the focus was on originally, and
 the destination row element after the focus has moved.
 
--   Type: `Function`
 -   Required: No
 
-###### onCollapseRow( row: HTMLElement )
+###### `onCollapseRow`: `( row: HTMLElement ) => void`
 
 A callback that passes in the row element to be collapsed.
 
--   Type: `Function`
 -   Required: No
 
-###### onExpandRow( row: HTMLElement )
+###### `onExpandRow`: `( row: HTMLElement ) => void`
 
 A callback that passes in the row element to be expanded.
 
--   Type: `Function`
 -   Required: No
 
 #### TreeGridRow
@@ -141,32 +105,28 @@ A callback that passes in the row element to be expanded.
 
 Additional props other than those specified below will be passed to the `tr` element rendered by `TreeGridRow`, so for example, it is possible to also set a `className` on a row.
 
-###### level
+###### `level`: `number`
 
 An integer value designating the level in the hierarchical tree structure. Counting starts at 1. A value of `1` indicates the root level of the structure.
 
--   Type: `Number`
 -   Required: Yes
 
-###### positionInSet
+###### `positionInSet`: `number`
 
 An integer value that represents the position in the set. A set is the count of elements at a specific level. Counting starts at 1.
 
--   Type: `Number`
 -   Required: Yes
 
-###### setSize
+###### `setSize`: `number`
 
-An integer value that represents the total number of items in the set ... that is the total number of items at this specific level of the hierarchy.
+An integer value that represents the total number of items in the set, at this specific level of the hierarchy.
 
--   Type: `Number`
 -   Required: Yes
 
-###### isExpanded
+###### `isExpanded`: `boolean`
 
 An optional value that designates whether a row is expanded or collapsed. Currently this value only sets the correct aria-expanded property on a row, it has no other built-in behavior.
 
--   Type: `Boolean`
 -   Required: No
 
 ### TreeGridCell
@@ -182,14 +142,14 @@ An optional value that designates whether a row is expanded or collapsed. Curren
 ```jsx
 <TreeGridCell>
 	{ ( props ) => (
-		<Button onClick={ onMoveDown } { ...props }>
-			Move Down
+		<Button onClick={ doSomething } { ...props }>
+			Do something
 		</Button>
 	) }
 </TreeGridCell>
 ```
 
-Props passed as an argument to the render prop must be passed to the child focusable component/element within the cell. If a component is used, it must correctly handle the `onFocus`, `tabIndex`, and `ref` props, passing these to the element it renders. These props are used to handle the roving tab index functionality of the tree grid.
+Props passed as an argument to the render prop must be passed to the child focusable component/element within the cell. If a component is used, it must correctly handle the `onFocus`, `tabIndex`, and `ref` props, passing these to the element it renders. These props are used to handle the roving tabindex functionality of the tree grid.
 
 ## Related components
 

packages/components/src/tree-grid/cell.tsx

@@ -0,0 +1,41 @@
+/**
+ * WordPress dependencies
+ */
+import { forwardRef } from '@wordpress/element';
+
+/**
+ * Internal dependencies
+ */
+import TreeGridItem from './item';
+import type { WordPressComponentProps } from '../ui/context';
+import type { TreeGridCellProps } from './types';
+
+function UnforwardedTreeGridCell(
+	{
+		children,
+		withoutGridItem = false,
+		...props
+	}: WordPressComponentProps< TreeGridCellProps, 'td', false >,
+	ref: React.ForwardedRef< any >
+) {
+	return (
+		<td { ...props } role="gridcell">
+			{ withoutGridItem ? (
+				<>{ children }</>
+			) : (
+				<TreeGridItem ref={ ref }>{ children }</TreeGridItem>
+			) }
+		</td>
+	);
+}
+
+/**
+ * `TreeGridCell` is used to create a tree hierarchy.
+ * It is not a visually styled component, but instead helps with adding
+ * keyboard navigation and roving tab index behaviors to tree grid structures.
+ *
+ * @see {@link https://www.w3.org/TR/wai-aria-practices/examples/treegrid/treegrid-1.html}
+ */
+export const TreeGridCell = forwardRef( UnforwardedTreeGridCell );
+
+export default TreeGridCell;