Table
A static tabular structure for displaying data with rows and columns.
Demo
Basic Table
A simple static table displaying data. No interactive features.
Sortable Table
Click column headers to sort. Uses aria-sort to indicate sort direction. This demo
uses a React component with client:load for interactive sorting.
With Row Headers
First cell in each row uses role="rowheader" for better screen reader navigation.
Virtualization Support
For large datasets, use aria-rowcount, aria-colcount, and
aria-rowindex to communicate the full table structure.
Spanning Cells
Cells can span multiple columns or rows using colspan and rowspan.
This implementation uses CSS Grid with grid-column: span N and
grid-row: span N for visual spanning, plus aria-colspan and
aria-rowspan for screen reader accessibility.
Native HTML
Use Native HTML First
Before using this custom component, consider using native <table>
elements.
They provide built-in semantics, work without JavaScript, and require no ARIA attributes.
<table>
<caption>User List</caption>
<thead>
<tr>
<th>Name</th>
<th>Age</th>
<th>City</th>
</tr>
</thead>
<tbody>
<tr>
<td>Alice</td>
<td>30</td>
<td>Tokyo</td>
</tr>
</tbody>
</table>
Use custom implementations only when you need CSS Grid/Flexbox layouts for responsive tables, or
when you cannot use native <table> elements due to design constraints.
| Use Case | Native HTML | Custom Implementation |
|---|---|---|
| Basic tabular data | Recommended | Not needed |
| JavaScript disabled support | Works natively | Requires fallback |
| Built-in accessibility | Automatic | Manual ARIA required |
| CSS Grid/Flexbox layout | Limited (display: table) | Full control |
| Responsive column reordering | Limited | Full control |
| Virtualization support | Not built-in | With ARIA support |
The native <table> element with <thead>,
<tbody>, <th>, and <td> provides complete
semantic structure automatically. The ARIA table pattern is only necessary when using non-table elements
(e.g., <div>) for layout purposes.
Accessibility Features
WAI-ARIA Roles
| Role | Element | Description |
|---|---|---|
table | Container element | Identifies the element as a table structure containing rows and cells of data. |
rowgroup | Header/Body container |
Groups rows together (equivalent to <thead>, <tbody>, <tfoot>).
|
row | Row element |
A row of cells within the table (equivalent to <tr>).
|
columnheader | Header cell |
A header cell for a column (equivalent to <th> in header row).
|
rowheader | Header cell |
A header cell for a row (equivalent to <th scope="row">).
|
cell | Data cell | A data cell within a row (equivalent to <td>). |
The table role creates a static tabular structure for displaying data. Unlike the
grid role, tables are not interactive and do not support keyboard navigation between
cells.
WAI-ARIA Properties
aria-label / aria-labelledby
Provides an accessible name for the table. One of these is required for screen reader users to understand the table's purpose.
| Type | String / ID reference |
| Required | Yes (one or the other) |
| Example | aria-label="User List" |
aria-describedby
References an element providing additional description for the table.
| Type | ID reference |
| Required | No |
WAI-ARIA States
aria-sort
Indicates the current sort direction of a column. Applied to columnheader or
rowheader elements.
| Values | ascending, descending, none, other |
| Required | No (only for sortable columns) |
| Updated | When sort order changes |
Virtualization Support
For large tables that only render visible rows/columns, these attributes help assistive technologies understand the full table structure:
aria-colcount / aria-rowcount
Defines the total number of columns/rows in the table when only a subset is rendered.
| Type | Number |
| Applied to | table role element
|
| Required | No (only for virtualized tables) |
aria-colindex / aria-rowindex
Indicates the position of a cell or row within the full table.
| Type | Number (1-based) |
| Applied to | aria-colindex on cells, aria-rowindex on rows
|
| Required | No (only for virtualized tables) |
Keyboard Support
Not applicable. The table pattern is a static structure and is not interactive. Unlike
the grid pattern, users cannot navigate between cells using arrow keys. Interactive elements
within cells (buttons, links) receive focus through normal tab order.
Accessible Naming
Tables must have an accessible name. Options include:
-
aria-label- Provides an invisible label for the table -
aria-labelledby- References an external element as the label - Caption element - A visible caption can provide the accessible name if properly associated
Table vs Grid
Understanding when to use table vs grid roles:
| Feature | Table | Grid |
|---|---|---|
| Purpose | Static data display | Interactive data manipulation |
| Keyboard navigation | Not applicable | Arrow keys between cells |
| Cell selection | Not supported | Via aria-selected |
| Focus management | None required | Roving tabindex |
References
Source Code
---
/**
* APG Table Pattern - Astro Implementation
*
* A static tabular structure for displaying data.
* Uses Web Components for sort button interactions.
*
* @see https://www.w3.org/WAI/ARIA/apg/patterns/table/
*/
export interface TableColumn {
id: string;
header: string;
/** Column is sortable */
sortable?: boolean;
/** Current sort direction */
sort?: 'ascending' | 'descending' | 'none';
}
/**
* Cell with spanning support
*/
export interface TableCell {
content: string;
/** Number of columns this cell spans */
colspan?: number;
/** Number of rows this cell spans */
rowspan?: number;
}
/**
* Cell value - can be simple string or object with spanning
*/
export type TableCellValue = string | TableCell;
/**
* Type guard to check if cell is a TableCell object
*/
function isTableCell(cell: TableCellValue): cell is TableCell {
return typeof cell === 'object' && cell !== null && 'content' in cell;
}
export interface TableRow {
id: string;
cells: TableCellValue[];
/** First cell is row header */
hasRowHeader?: boolean;
/** Row index for virtualization (1-based) */
rowIndex?: number;
}
export interface Props {
/** Column definitions */
columns: TableColumn[];
/** Row data */
rows: TableRow[];
/** Caption text (optional) */
caption?: string;
// Virtualization support
/** Total number of columns (for virtualization) */
totalColumns?: number;
/** Total number of rows (for virtualization) */
totalRows?: number;
/** Starting column index (1-based, for virtualization) */
startColIndex?: number;
/** Additional CSS class */
class?: string;
/** Table id */
id?: string;
/** Accessible label */
'aria-label'?: string;
/** Reference to external label element */
'aria-labelledby'?: string;
/** Reference to description element */
'aria-describedby'?: string;
}
const {
columns,
rows,
caption,
totalColumns,
totalRows,
startColIndex,
class: className = '',
id,
'aria-label': ariaLabel,
'aria-labelledby': ariaLabelledby,
'aria-describedby': ariaDescribedby,
} = Astro.props;
function getSortIcon(sort?: 'ascending' | 'descending' | 'none'): string {
if (sort === 'ascending') return '▲';
if (sort === 'descending') return '▼';
return '⇅';
}
function getCellGridStyle(cell: TableCellValue): string | undefined {
if (!isTableCell(cell)) return undefined;
const styles: string[] = [];
if (cell.colspan && cell.colspan > 1) {
styles.push(`grid-column: span ${cell.colspan}`);
}
if (cell.rowspan && cell.rowspan > 1) {
styles.push(`grid-row: span ${cell.rowspan}`);
}
return styles.length > 0 ? styles.join('; ') : undefined;
}
---
<apg-table class={`apg-table ${className}`.trim()} style={`--table-cols: ${columns.length}`}>
<div
role="table"
aria-label={ariaLabel}
aria-labelledby={ariaLabelledby}
aria-describedby={ariaDescribedby}
aria-colcount={totalColumns}
aria-rowcount={totalRows}
id={id}
>
{caption && <div class="apg-table-caption">{caption}</div>}
{/* Header rowgroup */}
<div role="rowgroup" class="apg-table-header">
<div role="row" class="apg-table-row">
{
columns.map((column, colIndex) => (
<div
role="columnheader"
class="apg-table-columnheader"
aria-sort={column.sortable ? column.sort || 'none' : undefined}
aria-colindex={startColIndex !== undefined ? startColIndex + colIndex : undefined}
>
{column.sortable ? (
<button
type="button"
class="apg-table-sort-button"
data-sort-column={column.id}
data-current-sort={column.sort || 'none'}
aria-label={`Sort by ${column.header}`}
>
{column.header}
<span class="apg-table-sort-icon" aria-hidden="true">
{getSortIcon(column.sort)}
</span>
</button>
) : (
column.header
)}
</div>
))
}
</div>
</div>
{/* Body rowgroup */}
<div role="rowgroup" class="apg-table-body">
{
rows.map((row) => (
<div role="row" class="apg-table-row" aria-rowindex={row.rowIndex}>
{row.cells.map((cell, cellIndex) => {
const isRowHeader = row.hasRowHeader && cellIndex === 0;
const cellRole = isRowHeader ? 'rowheader' : 'cell';
const cellData = isTableCell(cell) ? cell : { content: cell };
const gridStyle = getCellGridStyle(cell);
return (
<div
role={cellRole}
class={`apg-table-${cellRole}`}
style={gridStyle}
aria-colindex={
startColIndex !== undefined ? startColIndex + cellIndex : undefined
}
aria-colspan={
cellData.colspan && cellData.colspan > 1 ? cellData.colspan : undefined
}
aria-rowspan={
cellData.rowspan && cellData.rowspan > 1 ? cellData.rowspan : undefined
}
>
{cellData.content}
</div>
);
})}
</div>
))
}
</div>
</div>
</apg-table>
<script>
class ApgTable extends HTMLElement {
connectedCallback() {
this.setupSortHandlers();
}
private setupSortHandlers() {
const sortButtons = this.querySelectorAll('[data-sort-column]');
sortButtons.forEach((button) => {
button.addEventListener('click', (e) => {
const target = e.currentTarget as HTMLElement;
const columnId = target.dataset.sortColumn;
const currentSort = target.dataset.currentSort;
const newDirection = currentSort === 'ascending' ? 'descending' : 'ascending';
this.dispatchEvent(
new CustomEvent('sortchange', {
detail: { columnId, direction: newDirection },
bubbles: true,
})
);
});
});
}
}
if (!customElements.get('apg-table')) {
customElements.define('apg-table', ApgTable);
}
</script> Usage
---
import Table from './Table.astro';
const columns = [
{ id: 'name', header: 'Name' },
{ id: 'age', header: 'Age' },
{ id: 'city', header: 'City' },
];
const rows = [
{ id: '1', cells: ['Alice', '30', 'Tokyo'] },
{ id: '2', cells: ['Bob', '25', 'Osaka'] },
{ id: '3', cells: ['Charlie', '35', 'Kyoto'] },
];
// Sortable columns
const sortableColumns = [
{ id: 'name', header: 'Name', sortable: true, sort: 'ascending' as const },
{ id: 'age', header: 'Age', sortable: true },
{ id: 'city', header: 'City' },
];
// With row headers
const rowsWithHeaders = [
{ id: '1', cells: ['Alice', '30', 'Tokyo'], hasRowHeader: true },
{ id: '2', cells: ['Bob', '25', 'Osaka'], hasRowHeader: true },
];
---
<!-- Basic table -->
<Table columns={columns} rows={rows} aria-label="User List" />
<!-- Sortable table -->
<Table
columns={sortableColumns}
rows={rows}
aria-label="Sortable User List"
/>
<!-- With row headers -->
<Table
columns={columns}
rows={rowsWithHeaders}
aria-label="User List with Row Headers"
/> API
Table Props
| Prop | Type | Default | Description |
|---|---|---|---|
columns | TableColumn[] | required | Column definitions |
rows | TableRow[] | required | Row data |
caption | string | - | Optional table caption |
totalColumns | number | - | Total columns (for virtualization) |
totalRows | number | - | Total rows (for virtualization) |
startColIndex | number | - | Starting column index (1-based) |
TableColumn Interface
interface TableColumn {
id: string;
header: string;
sortable?: boolean;
sort?: 'ascending' | 'descending' | 'none';
} TableRow Interface
interface TableCell {
content: string;
colspan?: number; // Columns spanned (visual + aria-colspan)
rowspan?: number; // Rows spanned (visual + aria-rowspan)
}
type TableCellValue = string | TableCell;
interface TableRow {
id: string;
cells: TableCellValue[];
hasRowHeader?: boolean;
rowIndex?: number; // For virtualization (1-based)
} Web Component Events
The Astro implementation uses a Web Component (apg-table) that emits a
sortchange custom event when sort buttons are clicked.
// Listen for sort changes
document.querySelector('apg-table').addEventListener('sortchange', (e) => {
console.log(e.detail); // { columnId: 'name', direction: 'descending' }
}); Testing
Tests verify APG compliance for ARIA roles, table structure, and accessibility requirements. Since Table is a static structure, keyboard interaction tests are not applicable.
Test Categories
High Priority : ARIA Structure
| Test | Description |
|---|---|
role="table" | Container element has the table role |
role="rowgroup" | Header and body groups have rowgroup role |
role="row" | All rows have the row role |
role="columnheader" | Header cells have columnheader role |
role="rowheader" | Row header cells have rowheader role when specified |
role="cell" | Data cells have the cell role |
High Priority : Accessible Name
| Test | Description |
|---|---|
aria-label | Accessible name via aria-label attribute |
aria-labelledby | Accessible name via external element reference |
caption | Caption is displayed when provided |
High Priority : Sort State
| Test | Description |
|---|---|
aria-sort="ascending" | Column sorted in ascending order |
aria-sort="descending" | Column sorted in descending order |
aria-sort="none" | Sortable column that is not currently sorted |
no aria-sort | Non-sortable columns have no aria-sort attribute |
onSortChange callback | Callback is invoked when sort button is clicked |
sort toggle | Clicking sorted column toggles direction |
Medium Priority : Virtualization Support
| Test | Description |
|---|---|
aria-colcount | Total column count for virtualized tables |
aria-rowcount | Total row count for virtualized tables |
aria-rowindex | Row position in the full table |
aria-colindex | Cell position in the full table |
Medium Priority : Visual Cell Spanning (Browser Tests)
| Test | Description |
|---|---|
colspan width | Cell with colspan=2 has ~2x width of normal cell |
rowspan height | Cell with rowspan=2 has ~2x height of normal cell |
full span | Cell spanning all columns matches table width |
combined spans | Cell with both colspan and rowspan has correct dimensions |
Note: Visual spanning tests use getBoundingClientRect() and require a real browser environment (Vitest browser mode with Playwright). These tests are in *.browser.test.ts files.
Medium Priority : Accessibility
| Test | Description |
|---|---|
axe violations | No accessibility violations detected by axe-core |
sortable columns | No violations with sortable column headers |
row headers | No violations with row header cells |
empty table | No violations with empty data rows |
Medium Priority : Edge Cases
| Test | Description |
|---|---|
empty rows | Table renders correctly with no data rows |
single column | Table handles single column correctly |
Low Priority : HTML Attribute Inheritance
| Test | Description |
|---|---|
className | Custom class is applied to container |
id | ID attribute is set correctly |
data-* | Data attributes are passed through |
Testing Tools
- Playwright (opens in new tab) - E2E testing for cross-framework validation
- Testing Library (opens in new tab) - Framework-specific testing utilities (React, Vue, Svelte)
- axe-core (opens in new tab) - Automated accessibility testing
E2E Test Code
The following Playwright tests verify Table behavior across all four frameworks (React, Vue, Svelte, Astro). Tests cover ARIA structure, sort state, virtualization attributes, and visual cell spanning.
import { test, expect } from '@playwright/test';
import AxeBuilder from '@axe-core/playwright';
/**
* E2E Tests for Table Pattern
*
* Test coverage based on APG Table pattern and llm.md Test Checklist:
*
* High Priority: ARIA Structure
* - Container has role="table"
* - All rows have role="row"
* - Data cells have role="cell"
* - Column headers have role="columnheader"
* - Row headers have role="rowheader" (when present)
* - Groups have role="rowgroup" (when present)
*
* High Priority: Accessible Name
* - Table has accessible name via aria-label
*
* High Priority: Sort State
* - Sorted column has aria-sort="ascending" or "descending"
* - Unsorted sortable columns have aria-sort="none"
* - Sort changes update aria-sort attribute
*
* Medium Priority: Virtualization
* - aria-rowcount matches total rows
* - aria-rowindex is 1-based on rows
*
* Medium Priority: Cell Spanning
* - aria-colspan is set when cell spans >1 columns
* - aria-rowspan is set when cell spans >1 rows
* - Visual spanning matches ARIA attributes
*
* Medium Priority: Accessibility
* - No axe-core violations (WCAG 2.1 AA)
*/
const frameworks = ['react', 'vue', 'svelte', 'astro'] as const;
for (const framework of frameworks) {
test.describe(`Table (${framework})`, () => {
test.beforeEach(async ({ page }) => {
await page.goto(`patterns/table/${framework}/`);
// Wait for first table to be visible instead of networkidle (more stable)
await expect(page.locator('[role="table"]').first()).toBeVisible();
});
// =========================================================================
// High Priority: ARIA Structure
// =========================================================================
test.describe('APG: ARIA Structure', () => {
test('required demos are present (sortable, row headers, spanning)', async ({ page }) => {
// Verify all required demo tables are present
await expect(page.locator('[role="table"][aria-label="Sortable User List"]')).toBeVisible();
await expect(
page.locator('[role="table"][aria-label="User List with Row Headers"]')
).toBeVisible();
await expect(page.locator('[role="table"][aria-label*="Spanning"]')).toBeVisible();
});
test('has role="table" on container', async ({ page }) => {
const tables = page.locator('[role="table"]');
await expect(tables.first()).toBeVisible();
// Multiple tables on the demo page
expect(await tables.count()).toBeGreaterThanOrEqual(1);
});
test('has role="row" on all rows', async ({ page }) => {
// Check the basic table (first one)
const basicTable = page.locator('[role="table"][aria-label="User List"]');
await expect(basicTable).toBeVisible();
const rows = basicTable.locator('[role="row"]');
// 1 header row + 5 data rows = 6 rows
await expect(rows).toHaveCount(6);
});
test('has role="columnheader" on header cells', async ({ page }) => {
const basicTable = page.locator('[role="table"][aria-label="User List"]');
await expect(basicTable).toBeVisible();
const headers = basicTable.locator('[role="columnheader"]');
// 3 columns: Name, Age, City
await expect(headers).toHaveCount(3);
await expect(headers.nth(0)).toContainText('Name');
await expect(headers.nth(1)).toContainText('Age');
await expect(headers.nth(2)).toContainText('City');
});
test('has role="cell" on data cells', async ({ page }) => {
const basicTable = page.locator('[role="table"][aria-label="User List"]');
await expect(basicTable).toBeVisible();
const cells = basicTable.locator('[role="cell"]');
// 5 rows x 3 columns = 15 cells
await expect(cells).toHaveCount(15);
});
test('has role="rowgroup" for header and body sections', async ({ page }) => {
const basicTable = page.locator('[role="table"][aria-label="User List"]');
await expect(basicTable).toBeVisible();
const rowgroups = basicTable.locator('[role="rowgroup"]');
// 2 rowgroups: header and body
await expect(rowgroups).toHaveCount(2);
});
test('has role="rowheader" when hasRowHeader is true', async ({ page }) => {
// Use the table with row headers
const rowHeaderTable = page.locator(
'[role="table"][aria-label="User List with Row Headers"]'
);
await expect(rowHeaderTable).toBeVisible();
const rowheaders = rowHeaderTable.locator('[role="rowheader"]');
// 3 data rows with row headers
await expect(rowheaders).toHaveCount(3);
// Verify the first row header contains expected content
await expect(rowheaders.first()).toContainText('Alice');
});
});
// =========================================================================
// High Priority: Accessible Name
// =========================================================================
test.describe('APG: Accessible Name', () => {
test('table has accessible name via aria-label', async ({ page }) => {
const basicTable = page.locator('[role="table"][aria-label="User List"]');
await expect(basicTable).toBeVisible();
await expect(basicTable).toHaveAttribute('aria-label', 'User List');
});
test('all tables have accessible names', async ({ page }) => {
const tables = page.locator('[role="table"]');
const count = await tables.count();
for (let i = 0; i < count; i++) {
const table = tables.nth(i);
const ariaLabel = await table.getAttribute('aria-label');
const ariaLabelledby = await table.getAttribute('aria-labelledby');
// Each table must have either aria-label or aria-labelledby
expect(ariaLabel || ariaLabelledby).toBeTruthy();
}
});
});
// =========================================================================
// High Priority: Sort State
// =========================================================================
test.describe('APG: Sort State', () => {
test('sorted column has aria-sort="ascending"', async ({ page }) => {
const sortableTable = page.locator('[role="table"][aria-label="Sortable User List"]');
await expect(sortableTable).toBeVisible();
// Name column is initially sorted ascending
const nameHeader = sortableTable
.locator('[role="columnheader"]')
.filter({ hasText: 'Name' });
await expect(nameHeader).toHaveAttribute('aria-sort', 'ascending');
});
test('unsorted sortable columns have aria-sort="none"', async ({ page }) => {
const sortableTable = page.locator('[role="table"][aria-label="Sortable User List"]');
await expect(sortableTable).toBeVisible();
// Age and City columns should have aria-sort="none"
const ageHeader = sortableTable.locator('[role="columnheader"]').filter({ hasText: 'Age' });
const cityHeader = sortableTable
.locator('[role="columnheader"]')
.filter({ hasText: 'City' });
await expect(ageHeader).toHaveAttribute('aria-sort', 'none');
await expect(cityHeader).toHaveAttribute('aria-sort', 'none');
});
test('clicking sort button changes aria-sort', async ({ page }) => {
const sortableTable = page.locator('[role="table"][aria-label="Sortable User List"]');
await expect(sortableTable).toBeVisible();
const ageHeader = sortableTable.locator('[role="columnheader"]').filter({ hasText: 'Age' });
const sortButton = ageHeader.locator('button');
// Initially none
await expect(ageHeader).toHaveAttribute('aria-sort', 'none');
// Click to sort ascending
await sortButton.click();
await expect(ageHeader).toHaveAttribute('aria-sort', 'ascending');
// Name should now be none
const nameHeader = sortableTable
.locator('[role="columnheader"]')
.filter({ hasText: 'Name' });
await expect(nameHeader).toHaveAttribute('aria-sort', 'none');
// Click again to sort descending
await sortButton.click();
await expect(ageHeader).toHaveAttribute('aria-sort', 'descending');
});
test('data rows are reordered when sort changes', async ({ page }) => {
const sortableTable = page.locator('[role="table"][aria-label="Sortable User List"]');
await expect(sortableTable).toBeVisible();
// Click Age column to sort ascending (youngest first)
const ageHeader = sortableTable.locator('[role="columnheader"]').filter({ hasText: 'Age' });
await ageHeader.locator('button').click();
// The first data row should now have the youngest person (Bob, 25)
// Use toContainText to handle whitespace variations
const firstCell = sortableTable.locator(
'[role="rowgroup"]:last-child [role="row"]:first-child [role="cell"]:first-child'
);
await expect(firstCell).toContainText('Bob');
});
});
// =========================================================================
// Medium Priority: Virtualization
// =========================================================================
test.describe('APG: Virtualization', () => {
test('aria-rowcount indicates total rows', async ({ page }) => {
const virtualizedTable = page.locator('[role="table"][aria-label*="Virtualized"]');
await expect(virtualizedTable).toBeVisible();
// Total rows is set to totalRows prop value (100 data rows, not including header)
await expect(virtualizedTable).toHaveAttribute('aria-rowcount', '100');
});
test('aria-colcount indicates total columns', async ({ page }) => {
const virtualizedTable = page.locator('[role="table"][aria-label*="Virtualized"]');
await expect(virtualizedTable).toBeVisible();
await expect(virtualizedTable).toHaveAttribute('aria-colcount', '3');
});
test('data rows have aria-rowindex indicating position', async ({ page }) => {
const virtualizedTable = page.locator('[role="table"][aria-label*="Virtualized"]');
await expect(virtualizedTable).toBeVisible();
// Data rows have rowIndex values from the demo data (5, 6, 7, 8, 9)
const dataRows = virtualizedTable.locator('[role="rowgroup"]:last-child [role="row"]');
await expect(dataRows.nth(0)).toHaveAttribute('aria-rowindex', '5');
await expect(dataRows.nth(1)).toHaveAttribute('aria-rowindex', '6');
await expect(dataRows.nth(2)).toHaveAttribute('aria-rowindex', '7');
await expect(dataRows.nth(3)).toHaveAttribute('aria-rowindex', '8');
await expect(dataRows.nth(4)).toHaveAttribute('aria-rowindex', '9');
});
test('cells have aria-colindex indicating column position', async ({ page }) => {
const virtualizedTable = page.locator('[role="table"][aria-label*="Virtualized"]');
await expect(virtualizedTable).toBeVisible();
// First row cells should have colindex 1, 2, 3
const firstRowCells = virtualizedTable.locator(
'[role="rowgroup"]:last-child [role="row"]:first-child [role="cell"]'
);
await expect(firstRowCells.nth(0)).toHaveAttribute('aria-colindex', '1');
await expect(firstRowCells.nth(1)).toHaveAttribute('aria-colindex', '2');
await expect(firstRowCells.nth(2)).toHaveAttribute('aria-colindex', '3');
});
});
// =========================================================================
// Medium Priority: Cell Spanning
// =========================================================================
test.describe('APG: Cell Spanning', () => {
test('aria-colspan and aria-rowspan attributes are present', async ({ page }) => {
const spanningTable = page.locator('[role="table"][aria-label*="Spanning"]');
await expect(spanningTable).toBeVisible();
// Verify colspan attributes exist
const colspanCells = spanningTable.locator('[aria-colspan]');
await expect(colspanCells).toHaveCount(2); // N/A (colspan=2) and Total (colspan=4)
// Verify rowspan attributes exist
const rowspanCells = spanningTable.locator('[aria-rowspan]');
await expect(rowspanCells).toHaveCount(1); // Electronics (rowspan=2)
// Verify specific values
await expect(spanningTable.locator('[aria-colspan="2"]')).toHaveCount(1);
await expect(spanningTable.locator('[aria-colspan="4"]')).toHaveCount(1);
await expect(spanningTable.locator('[aria-rowspan="2"]')).toHaveCount(1);
});
test('colspan=2 cell is visually wider than single column header', async ({ page }) => {
const spanningTable = page.locator('[role="table"][aria-label*="Spanning"]');
await expect(spanningTable).toBeVisible();
const colspanCell = spanningTable.locator('[aria-colspan="2"]').first();
await expect(colspanCell).toBeVisible();
// Use header cell as reference (more consistent sizing than data cells)
const headerCell = spanningTable.locator('[role="columnheader"]').first();
await expect(headerCell).toBeVisible();
// Wait for layout to stabilize and verify colspan cell is wider
// Using header width as baseline: colspan=2 should be ~2x header width
await expect
.poll(
async () => {
const [colspanBox, headerBox] = await Promise.all([
colspanCell.boundingBox(),
headerCell.boundingBox(),
]);
if (!colspanBox || !headerBox || headerBox.width === 0) return 0;
return colspanBox.width / headerBox.width;
},
{ timeout: 5000 }
)
.toBeGreaterThan(1.5); // Allow some tolerance for padding/borders
});
test('colspan=4 cell spans most of the table width', async ({ page }) => {
const spanningTable = page.locator('[role="table"][aria-label*="Spanning"]');
await expect(spanningTable).toBeVisible();
const fullSpanCell = spanningTable.locator('[aria-colspan="4"]').first();
await expect(fullSpanCell).toBeVisible();
// Use header cell as reference
const headerCell = spanningTable.locator('[role="columnheader"]').first();
await expect(headerCell).toBeVisible();
// colspan=4 should be significantly wider than a single header
await expect
.poll(
async () => {
const [fullSpanBox, headerBox] = await Promise.all([
fullSpanCell.boundingBox(),
headerCell.boundingBox(),
]);
if (!fullSpanBox || !headerBox || headerBox.width === 0) return 0;
return fullSpanBox.width / headerBox.width;
},
{ timeout: 5000 }
)
.toBeGreaterThan(3.0); // Should be ~4x but allow tolerance
});
test('rowspan=2 cell is visually taller than single row', async ({ page }) => {
const spanningTable = page.locator('[role="table"][aria-label*="Spanning"]');
await expect(spanningTable).toBeVisible();
const rowspanCell = spanningTable.locator('[aria-rowspan="2"]').first();
await expect(rowspanCell).toBeVisible();
// Use a normal data cell in the same table as reference
const normalCell = spanningTable
.locator('[role="cell"]:not([aria-colspan]):not([aria-rowspan])')
.first();
await expect(normalCell).toBeVisible();
// rowspan=2 should be ~2x the height of a normal cell
await expect
.poll(
async () => {
const [rowspanBox, normalBox] = await Promise.all([
rowspanCell.boundingBox(),
normalCell.boundingBox(),
]);
if (!rowspanBox || !normalBox || normalBox.height === 0) return 0;
return rowspanBox.height / normalBox.height;
},
{ timeout: 5000 }
)
.toBeGreaterThan(1.5); // Allow some tolerance
});
});
// =========================================================================
// Medium Priority: Accessibility
// =========================================================================
test.describe('Accessibility', () => {
test('has no axe-core violations', async ({ page }) => {
const accessibilityScanResults = await new AxeBuilder({ page })
.include('[role="table"]')
.analyze();
expect(accessibilityScanResults.violations).toEqual([]);
});
});
});
} /**
* Table Astro Component Tests using Container API
*
* These tests verify the actual Table.astro component output using Astro's Container API.
* This ensures the component renders correct ARIA structure and attributes.
*
* @see https://docs.astro.build/en/reference/container-reference/
*/
import { experimental_AstroContainer as AstroContainer } from 'astro/container';
import { describe, it, expect, beforeEach } from 'vitest';
import { JSDOM } from 'jsdom';
import Table from './Table.astro';
// Import types from React implementation (types are shared across frameworks)
import type { TableColumn, TableRow, TableCell } from './Table';
describe('Table (Astro Container API)', () => {
let container: AstroContainer;
beforeEach(async () => {
container = await AstroContainer.create();
});
// Helper to render and parse HTML
async function renderTable(props: {
columns: TableColumn[];
rows: TableRow[];
caption?: string;
totalColumns?: number;
totalRows?: number;
startColIndex?: number;
'aria-label'?: string;
'aria-labelledby'?: string;
'aria-describedby'?: string;
class?: string;
id?: string;
}): Promise<Document> {
const html = await container.renderToString(Table, { props });
const dom = new JSDOM(html);
return dom.window.document;
}
const basicColumns: TableColumn[] = [
{ id: 'name', header: 'Name' },
{ id: 'age', header: 'Age' },
{ id: 'city', header: 'City' },
];
const basicRows: TableRow[] = [
{ id: '1', cells: ['Alice', '30', 'Tokyo'] },
{ id: '2', cells: ['Bob', '25', 'Osaka'] },
{ id: '3', cells: ['Charlie', '35', 'Kyoto'] },
];
const sortableColumns: TableColumn[] = [
{ id: 'name', header: 'Name', sortable: true, sort: 'ascending' },
{ id: 'age', header: 'Age', sortable: true },
{ id: 'city', header: 'City' },
];
// 🔴 High Priority: APG ARIA Structure
describe('APG: ARIA Structure', () => {
it('has role="table" on container', async () => {
const doc = await renderTable({
columns: basicColumns,
rows: basicRows,
'aria-label': 'Test Table',
});
const table = doc.querySelector('[role="table"]');
expect(table).not.toBeNull();
});
it('has role="rowgroup" on header and body groups', async () => {
const doc = await renderTable({
columns: basicColumns,
rows: basicRows,
'aria-label': 'Test Table',
});
const rowgroups = doc.querySelectorAll('[role="rowgroup"]');
expect(rowgroups).toHaveLength(2);
});
it('has role="row" on all rows', async () => {
const doc = await renderTable({
columns: basicColumns,
rows: basicRows,
'aria-label': 'Test Table',
});
const rows = doc.querySelectorAll('[role="row"]');
expect(rows).toHaveLength(4); // 1 header + 3 data
});
it('has role="columnheader" on header cells', async () => {
const doc = await renderTable({
columns: basicColumns,
rows: basicRows,
'aria-label': 'Test Table',
});
const headers = doc.querySelectorAll('[role="columnheader"]');
expect(headers).toHaveLength(3);
expect(headers[0]?.textContent).toContain('Name');
});
it('has role="cell" on data cells', async () => {
const doc = await renderTable({
columns: basicColumns,
rows: basicRows,
'aria-label': 'Test Table',
});
const cells = doc.querySelectorAll('[role="cell"]');
expect(cells).toHaveLength(9);
});
it('has role="rowheader" on row headers when hasRowHeader is true', async () => {
const rowsWithRowHeader: TableRow[] = [
{ id: '1', cells: ['Alice', '30', 'Tokyo'], hasRowHeader: true },
{ id: '2', cells: ['Bob', '25', 'Osaka'], hasRowHeader: true },
];
const doc = await renderTable({
columns: basicColumns,
rows: rowsWithRowHeader,
'aria-label': 'Test Table',
});
const rowheaders = doc.querySelectorAll('[role="rowheader"]');
expect(rowheaders).toHaveLength(2);
expect(rowheaders[0]?.textContent?.trim()).toBe('Alice');
});
});
// 🔴 High Priority: Accessible Name
describe('APG: Accessible Name', () => {
it('has accessible name via aria-label', async () => {
const doc = await renderTable({
columns: basicColumns,
rows: basicRows,
'aria-label': 'User List',
});
const table = doc.querySelector('[role="table"]');
expect(table?.getAttribute('aria-label')).toBe('User List');
});
it('has accessible name via aria-labelledby', async () => {
const doc = await renderTable({
columns: basicColumns,
rows: basicRows,
'aria-labelledby': 'table-title',
});
const table = doc.querySelector('[role="table"]');
expect(table?.getAttribute('aria-labelledby')).toBe('table-title');
});
it('has description via aria-describedby', async () => {
const doc = await renderTable({
columns: basicColumns,
rows: basicRows,
'aria-label': 'Test Table',
'aria-describedby': 'desc',
});
const table = doc.querySelector('[role="table"]');
expect(table?.getAttribute('aria-describedby')).toBe('desc');
});
it('displays caption when provided', async () => {
const doc = await renderTable({
columns: basicColumns,
rows: basicRows,
'aria-label': 'Test Table',
caption: 'User Data',
});
const caption = doc.querySelector('.apg-table-caption');
expect(caption?.textContent).toBe('User Data');
});
});
// 🔴 High Priority: Sort State
describe('APG: Sort State', () => {
it('has aria-sort="ascending" on ascending sorted column', async () => {
const doc = await renderTable({
columns: sortableColumns,
rows: basicRows,
'aria-label': 'Test Table',
});
const nameHeader = doc.querySelector('[role="columnheader"]');
expect(nameHeader?.getAttribute('aria-sort')).toBe('ascending');
});
it('has aria-sort="descending" on descending sorted column', async () => {
const columns: TableColumn[] = [
{ id: 'name', header: 'Name', sortable: true, sort: 'descending' },
{ id: 'age', header: 'Age', sortable: true },
];
const doc = await renderTable({
columns,
rows: basicRows,
'aria-label': 'Test Table',
});
const nameHeader = doc.querySelector('[role="columnheader"]');
expect(nameHeader?.getAttribute('aria-sort')).toBe('descending');
});
it('has aria-sort="none" on unsorted sortable columns', async () => {
const doc = await renderTable({
columns: sortableColumns,
rows: basicRows,
'aria-label': 'Test Table',
});
const headers = doc.querySelectorAll('[role="columnheader"]');
// Second column (Age) is sortable but not sorted
expect(headers[1]?.getAttribute('aria-sort')).toBe('none');
});
it('does not have aria-sort on non-sortable columns', async () => {
const doc = await renderTable({
columns: sortableColumns,
rows: basicRows,
'aria-label': 'Test Table',
});
const headers = doc.querySelectorAll('[role="columnheader"]');
// Third column (City) is not sortable
expect(headers[2]?.hasAttribute('aria-sort')).toBe(false);
});
it('sortable header has button with accessible name', async () => {
const doc = await renderTable({
columns: sortableColumns,
rows: basicRows,
'aria-label': 'Test Table',
});
const sortButton = doc.querySelector('[data-sort-column="name"]');
expect(sortButton).not.toBeNull();
expect(sortButton?.getAttribute('aria-label')).toContain('Name');
});
});
// 🟡 Medium Priority: Virtualization Support
describe('APG: Virtualization Support', () => {
it('has aria-colcount when totalColumns is provided', async () => {
const doc = await renderTable({
columns: basicColumns,
rows: basicRows,
'aria-label': 'Test Table',
totalColumns: 10,
});
const table = doc.querySelector('[role="table"]');
expect(table?.getAttribute('aria-colcount')).toBe('10');
});
it('has aria-rowcount when totalRows is provided', async () => {
const doc = await renderTable({
columns: basicColumns,
rows: basicRows,
'aria-label': 'Test Table',
totalRows: 100,
});
const table = doc.querySelector('[role="table"]');
expect(table?.getAttribute('aria-rowcount')).toBe('100');
});
it('has aria-rowindex on rows when rowIndex is provided', async () => {
const rowsWithIndex: TableRow[] = [
{ id: '1', cells: ['Alice', '30', 'Tokyo'], rowIndex: 5 },
{ id: '2', cells: ['Bob', '25', 'Osaka'], rowIndex: 6 },
];
const doc = await renderTable({
columns: basicColumns,
rows: rowsWithIndex,
'aria-label': 'Test Table',
totalRows: 100,
});
const rows = doc.querySelectorAll('[role="row"]');
// Skip header row (index 0)
expect(rows[1]?.getAttribute('aria-rowindex')).toBe('5');
expect(rows[2]?.getAttribute('aria-rowindex')).toBe('6');
});
it('has aria-colindex on cells when startColIndex is provided', async () => {
const doc = await renderTable({
columns: basicColumns,
rows: basicRows,
'aria-label': 'Test Table',
totalColumns: 10,
startColIndex: 3,
});
const firstDataRow = doc.querySelectorAll('[role="row"]')[1];
const cells = firstDataRow?.querySelectorAll('[role="cell"]');
expect(cells?.[0]?.getAttribute('aria-colindex')).toBe('3');
expect(cells?.[1]?.getAttribute('aria-colindex')).toBe('4');
expect(cells?.[2]?.getAttribute('aria-colindex')).toBe('5');
});
it('does not have virtualization attributes when not provided', async () => {
const doc = await renderTable({
columns: basicColumns,
rows: basicRows,
'aria-label': 'Test Table',
});
const table = doc.querySelector('[role="table"]');
expect(table?.hasAttribute('aria-colcount')).toBe(false);
expect(table?.hasAttribute('aria-rowcount')).toBe(false);
const rows = doc.querySelectorAll('[role="row"]');
expect(rows[1]?.hasAttribute('aria-rowindex')).toBe(false);
const cells = doc.querySelectorAll('[role="cell"]');
expect(cells[0]?.hasAttribute('aria-colindex')).toBe(false);
});
});
// 🟡 Medium Priority: Cell Spanning
describe('APG: Cell Spanning', () => {
it('has aria-colspan when cell spans multiple columns', async () => {
const rowsWithColspan: TableRow[] = [
{
id: '1',
cells: [{ content: 'Merged', colspan: 2 } as TableCell, 'Single'],
},
];
const doc = await renderTable({
columns: basicColumns,
rows: rowsWithColspan,
'aria-label': 'Test Table',
});
const cells = doc.querySelectorAll('[role="cell"]');
expect(cells[0]?.getAttribute('aria-colspan')).toBe('2');
expect(cells[1]?.hasAttribute('aria-colspan')).toBe(false);
});
it('has aria-rowspan when cell spans multiple rows', async () => {
const rowsWithRowspan: TableRow[] = [
{
id: '1',
cells: [{ content: 'Spans 2 rows', rowspan: 2 } as TableCell, 'A', 'B'],
},
{ id: '2', cells: ['C', 'D'] },
];
const doc = await renderTable({
columns: basicColumns,
rows: rowsWithRowspan,
'aria-label': 'Test Table',
});
const firstDataRow = doc.querySelectorAll('[role="row"]')[1];
const firstCell = firstDataRow?.querySelector('[role="cell"]');
expect(firstCell?.getAttribute('aria-rowspan')).toBe('2');
});
it('has grid-column span style for colspan cells', async () => {
const rowsWithColspan: TableRow[] = [
{
id: '1',
cells: [{ content: 'Merged', colspan: 2 } as TableCell, 'Single'],
},
];
const doc = await renderTable({
columns: basicColumns,
rows: rowsWithColspan,
'aria-label': 'Test Table',
});
const cells = doc.querySelectorAll('[role="cell"]');
const style = cells[0]?.getAttribute('style') || '';
expect(style).toContain('grid-column');
expect(style).toContain('span 2');
});
it('has grid-row span style for rowspan cells', async () => {
const rowsWithRowspan: TableRow[] = [
{
id: '1',
cells: [{ content: 'Spans 2 rows', rowspan: 2 } as TableCell, 'A', 'B'],
},
{ id: '2', cells: ['C', 'D'] },
];
const doc = await renderTable({
columns: basicColumns,
rows: rowsWithRowspan,
'aria-label': 'Test Table',
});
const firstDataRow = doc.querySelectorAll('[role="row"]')[1];
const firstCell = firstDataRow?.querySelector('[role="cell"]');
const style = firstCell?.getAttribute('style') || '';
expect(style).toContain('grid-row');
expect(style).toContain('span 2');
});
it('does not have aria-colspan when colspan is 1', async () => {
const rowsWithColspanOne: TableRow[] = [
{
id: '1',
cells: [{ content: 'Single', colspan: 1 } as TableCell, 'B', 'C'],
},
];
const doc = await renderTable({
columns: basicColumns,
rows: rowsWithColspanOne,
'aria-label': 'Test Table',
});
const cells = doc.querySelectorAll('[role="cell"]');
expect(cells[0]?.hasAttribute('aria-colspan')).toBe(false);
});
it('does not have aria-rowspan when rowspan is 1', async () => {
const rowsWithRowspanOne: TableRow[] = [
{
id: '1',
cells: [{ content: 'Single', rowspan: 1 } as TableCell, 'B', 'C'],
},
];
const doc = await renderTable({
columns: basicColumns,
rows: rowsWithRowspanOne,
'aria-label': 'Test Table',
});
const cells = doc.querySelectorAll('[role="cell"]');
expect(cells[0]?.hasAttribute('aria-rowspan')).toBe(false);
});
it('renders cell content correctly with TableCell object', async () => {
const rowsWithTableCell: TableRow[] = [
{
id: '1',
cells: [{ content: 'Cell Content', colspan: 2 } as TableCell, 'Normal'],
},
];
const doc = await renderTable({
columns: basicColumns,
rows: rowsWithTableCell,
'aria-label': 'Test Table',
});
const cells = doc.querySelectorAll('[role="cell"]');
expect(cells[0]?.textContent?.trim()).toBe('Cell Content');
expect(cells[1]?.textContent?.trim()).toBe('Normal');
});
});
// 🟡 Medium Priority: CSS Grid Layout
describe('CSS Grid Layout', () => {
it('has --table-cols CSS variable set to column count', async () => {
const doc = await renderTable({
columns: basicColumns,
rows: basicRows,
'aria-label': 'Test Table',
});
const tableContainer = doc.querySelector('.apg-table');
const style = tableContainer?.getAttribute('style') || '';
expect(style).toContain('--table-cols');
expect(style).toContain('3');
});
it('table container has apg-table class', async () => {
const doc = await renderTable({
columns: basicColumns,
rows: basicRows,
'aria-label': 'Test Table',
});
const tableContainer = doc.querySelector('.apg-table');
expect(tableContainer).not.toBeNull();
});
});
// 🟡 Medium Priority: Edge Cases
describe('Edge Cases', () => {
it('renders empty table with no rows', async () => {
const doc = await renderTable({
columns: basicColumns,
rows: [],
'aria-label': 'Empty Table',
});
const table = doc.querySelector('[role="table"]');
expect(table).not.toBeNull();
const cells = doc.querySelectorAll('[role="cell"]');
expect(cells).toHaveLength(0);
});
it('handles single column', async () => {
const singleColumn: TableColumn[] = [{ id: 'name', header: 'Name' }];
const singleColumnRows: TableRow[] = [
{ id: '1', cells: ['Alice'] },
{ id: '2', cells: ['Bob'] },
];
const doc = await renderTable({
columns: singleColumn,
rows: singleColumnRows,
'aria-label': 'Single Column Table',
});
expect(doc.querySelectorAll('[role="columnheader"]')).toHaveLength(1);
expect(doc.querySelectorAll('[role="cell"]')).toHaveLength(2);
});
it('handles single row', async () => {
const singleRow: TableRow[] = [{ id: '1', cells: ['Alice', '30', 'Tokyo'] }];
const doc = await renderTable({
columns: basicColumns,
rows: singleRow,
'aria-label': 'Single Row Table',
});
const rows = doc.querySelectorAll('[role="row"]');
expect(rows).toHaveLength(2); // 1 header + 1 data
});
it('applies custom class', async () => {
const doc = await renderTable({
columns: basicColumns,
rows: basicRows,
'aria-label': 'Test Table',
class: 'custom-table',
});
const tableContainer = doc.querySelector('.apg-table');
expect(tableContainer?.classList.contains('custom-table')).toBe(true);
});
it('applies custom id', async () => {
const doc = await renderTable({
columns: basicColumns,
rows: basicRows,
'aria-label': 'Test Table',
id: 'my-table',
});
const tableContainer = doc.querySelector('#my-table');
expect(tableContainer).not.toBeNull();
});
});
// 🟢 Low Priority: HTML Attributes
describe('HTML Attributes', () => {
it('Web Component wrapper uses apg-table element', async () => {
const doc = await renderTable({
columns: basicColumns,
rows: basicRows,
'aria-label': 'Test Table',
});
const webComponent = doc.querySelector('apg-table');
expect(webComponent).not.toBeNull();
});
});
}); Resources
- WAI-ARIA APG: Table Pattern (opens in new tab)
- MDN: <table> element (opens in new tab)
- AI Implementation Guide (llm.md) (opens in new tab) - ARIA specs, keyboard support, test checklist