Fix aria roles for table headers and cells

docs/Column.md

@@ -16,6 +16,7 @@ Describes the header and cell contents of a table column.
 | flexShrink | Number |  | Flex shrink style; defaults to 1 |
 | headerClassName | String |  | CSS class to apply to this column's header |
 | headerRenderer | Function |  | Optional callback responsible for rendering a column's header column. [Learn more](#headerrenderer) |
+| id | String |  | Optional id to set on the column header; used for [`aria-describedby`](https://www.w3.org/TR/wai-aria/states_and_properties#aria-describedby) |
 | label | String |  | Header label for this column |
 | maxWidth | Number |  | Maximum width of column; this property will only be used if :flexGrow is greater than 0 |
 | minWidth | Number |  | Minimum width of column |

source/Table/Column.js

@@ -52,6 +52,9 @@ export default class Column extends Component {
      */
     headerRenderer: PropTypes.func.isRequired,
 
+    /** Optional id to set on the column header */
+    id: PropTypes.string,
+
     /** Header label for this column */
     label: PropTypes.string,
 

source/Table/Table.jest.js

@@ -41,6 +41,7 @@ describe('Table', () => {
     cellDataGetter,
     cellRenderer,
     columnData = { data: 123 },
+    columnID,
     columnStyle,
     disableSort = false,
     headerRenderer,
@@ -70,6 +71,7 @@ describe('Table', () => {
           headerRenderer={headerRenderer}
           disableSort={disableSort}
           style={columnStyle}
+          id={columnID}
         />
         <Column
           label='Email'
@@ -885,6 +887,21 @@ describe('Table', () => {
       expect(row.getAttribute('role')).toEqual('row')
     })
 
+    it('should set aria role on a cell', () => {
+      const rendered = findDOMNode(render(getMarkup()))
+      const cell = rendered.querySelector('.ReactVirtualized__Table__rowColumn')
+      expect(cell.getAttribute('role')).toEqual('gridcell')
+    })
+
+    it('should set aria-describedby on a cell when the column has an id', () => {
+      const columnID = 'column-header-test'
+      const rendered = findDOMNode(render(getMarkup({
+        columnID
+      })))
+      const cell = rendered.querySelector('.ReactVirtualized__Table__rowColumn')
+      expect(cell.getAttribute('aria-describedby')).toEqual(columnID)
+    })
+
     it('should attach a11y properties to a row if :onRowClick is specified', () => {
       const rendered = findDOMNode(render(getMarkup({
         onRowClick: () => {}
@@ -903,14 +920,46 @@ describe('Table', () => {
       expect(row.tabIndex).toEqual(-1)
     })
 
+    it('should set aria role on a header column', () => {
+      const rendered = findDOMNode(render(getMarkup()))
+      const header = rendered.querySelector('.ReactVirtualized__Table__headerColumn')
+      expect(header.getAttribute('role')).toEqual('columnheader')
+    })
+
+    it('should set aria-sort ascending on a header column if the column is sorted ascending', () => {
+      const rendered = findDOMNode(render(getMarkup({
+        sortBy: 'name',
+        sortDirection: SortDirection.ASC
+      })))
+      const header = rendered.querySelector('.ReactVirtualized__Table__headerColumn')
+      expect(header.getAttribute('aria-sort')).toEqual('ascending')
+    })
+
+    it('should set aria-sort descending on a header column if the column is sorted descending', () => {
+      const rendered = findDOMNode(render(getMarkup({
+        sortBy: 'name',
+        sortDirection: SortDirection.DESC
+      })))
+      const header = rendered.querySelector('.ReactVirtualized__Table__headerColumn')
+      expect(header.getAttribute('aria-sort')).toEqual('descending')
+    })
+
+    it('should set id on a header column when the column has an id', () => {
+      const columnID = 'column-header-test'
+      const rendered = findDOMNode(render(getMarkup({
+        columnID
+      })))
+      const header = rendered.querySelector('.ReactVirtualized__Table__headerColumn')
+      expect(header.getAttribute('id')).toEqual(columnID)
+    })
+
     it('should attach a11y properties to a header column if sort is enabled', () => {
       const rendered = findDOMNode(render(getMarkup({
         disableSort: false,
         sort: () => {}
       })))
       const row = rendered.querySelector('.ReactVirtualized__Table__headerColumn')
       expect(row.getAttribute('aria-label')).toEqual('Name')
-      expect(row.getAttribute('role')).toEqual('rowheader')
       expect(row.tabIndex).toEqual(0)
     })
 
@@ -920,7 +969,6 @@ describe('Table', () => {
       })))
       const row = rendered.querySelector('.ReactVirtualized__Table__headerColumn')
       expect(row.getAttribute('aria-label')).toEqual(null)
-      expect(row.getAttribute('role')).toEqual(null)
       expect(row.tabIndex).toEqual(-1)
     })
   })

source/Table/Table.js

@@ -384,7 +384,8 @@ export default class Table extends PureComponent {
       cellRenderer,
       className,
       columnData,
-      dataKey
+      dataKey,
+      id
     } = column.props
 
     const cellData = cellDataGetter({ columnData, dataKey, rowData })
@@ -396,10 +397,18 @@ export default class Table extends PureComponent {
       ? renderedCell
       : null
 
+    const a11yProps = {}
+
+    if (id) {
+      a11yProps['aria-describedby'] = id
+    }
+
     return (
       <div
+        {...a11yProps}
         key={`Row${rowIndex}-Col${columnIndex}`}
         className={cn('ReactVirtualized__Table__rowColumn', className)}
+        role='gridcell'
         style={style}
         title={title}
       >
@@ -410,7 +419,7 @@ export default class Table extends PureComponent {
 
   _createHeader ({ column, index }) {
     const { headerClassName, headerStyle, onHeaderClick, sort, sortBy, sortDirection } = this.props
-    const { dataKey, disableSort, headerRenderer, label, columnData } = column.props
+    const { dataKey, disableSort, headerRenderer, id, label, columnData } = column.props
     const sortEnabled = !disableSort && sort
 
     const classNames = cn(
@@ -455,17 +464,27 @@ export default class Table extends PureComponent {
       }
 
       a11yProps['aria-label'] = column.props['aria-label'] || label || dataKey
-      a11yProps.role = 'rowheader'
       a11yProps.tabIndex = 0
       a11yProps.onClick = onClick
       a11yProps.onKeyDown = onKeyDown
     }
 
+    if (sortBy === dataKey) {
+      a11yProps['aria-sort'] = sortDirection === SortDirection.ASC
+        ? 'ascending'
+        : 'descending'
+    }
+
+    if (id) {
+      a11yProps.id = id
+    }
+
     return (
       <div
         {...a11yProps}
         key={`Header-Col${index}`}
         className={classNames}
+        role='columnheader'
         style={style}
       >
         {renderedHeader}