IBM/axe Accessibility Testing Guide

Reference material for how to test a given UI surface. This skill does not decide what to scan or drive a fix loop by itself — use it while writing tests, debugging a violation, or implementing a fix identified by ibm-a11y-route-scan, ibm-a11y-level1-audit, or ibm-a11y-pr-remediation.

When To Use

Use this skill for frontend work under src/frontend when the change affects:

• UI components, primitives, pages, routes, dialogs, drawers, popovers, dropdowns, tabs, accordions, tables, forms, navigation, or canvas controls.
• ARIA attributes, labels, roles, focus management, tab order, keyboard interaction, disabled states, loading states, or error states.
• A request to write, fix, or review an axe/IBM accessibility test.

Use alongside:

• frontend-testing for Jest/React Testing Library patterns.
• e2e-testing for Playwright patterns.
• frontend-i18n when adding or changing user-facing labels, accessible names, aria-label, tooltips, or visible strings.
• ibm-a11y-route-scan to batch-scan routes with the Python scanner and produce Markdown/HTML reports.
• ibm-a11y-level1-audit for a scoped IBM Level 1 compliance audit and report.
• ibm-a11y-pr-remediation to scan and fix an entire PR/branch end-to-end.

Goal

Do not stop at "run axe on default render." Inspect the changed UI and cover every meaningful user-visible state, for both keyboard and screen-reader users, that can expose accessibility bugs.

The Bar: two engines, both must pass

Automated a11y is not one tool. Run BOTH — they catch different classes of bug:

• axe-core — Jest axe() (@/utils/a11y-test), jsdom-only. Fast; strong on contrast, labels, roles, ARIA basics.
• IBM Equal Access — the stricter engine on ARIA structure and keyboard semantics; catches real WCAG Level-1 issues axe silently passes. Two entry points, same engine (aChecker):
  • Playwright page.runA11yScan(label) — runs aChecker.getCompliance in-browser on the live DOM, so it scans open modals / menus / selected / editing states. This is IBM, not axe (despite the name).
  • scripts/a11y/a11y_scan.py (see ibm-a11y-route-scan) — route scanner for the default-loaded page only.

A page that is green on axe is NOT done. When the change touches a table/tree/listbox/menu/composite widget, IBM is mandatory. Prefer page.runA11yScan for stateful surfaces (it sees the DOM after your interactions); use the Python scanner for a quick default-load route check.

Verify commands:

cd src/frontend
RUN_A11Y=true RUN_A11Y_ASSERT=true npx playwright test tests/a11y/<feature>.a11y.spec.ts --project=chromium --workers=5

# The Python scanner's playwright deps are NOT in the default `uv sync`.
# One-time: `uv run --with playwright playwright install chromium`
uv run --with playwright python scripts/a11y/a11y_scan.py \
  --url http://localhost:3000 \
  --routes /settings/<route> \
  --out /tmp/a11y.json --markdown /tmp/a11y.md --timeout-ms 45000

RUN_A11Y=true runs the scan; add RUN_A11Y_ASSERT=true to actually fail on new violations (without it the scan is informational). Both engines must report zero. After changing a shared component, re-scan every page that uses it, not just the one you touched.

First Pass

1. Read the changed files and nearby tests.
2. Identify the UI surface:
   • Primitive/component only
   • Composed component
   • Page/route
   • Stateful workflow
   • Shared helper that changes labels, roles, tab order, or focus behavior
3. List interactive surfaces:
   • Buttons, links, inputs, checkboxes, switches, radios, selects, comboboxes
   • Dropdown menus, popovers, dialogs, drawers, tooltips
   • Tabs, accordions, tables/treegrids, row actions, pagination
   • Keyboard-only interactions and focus traps
4. List states worth scanning:
   • Default, populated, empty, loading, error/validation visible
   • Disabled/read-only, selected/expanded/open
   • Modal/dropdown/popover open
   • Mobile viewport when layout changes

What To Check (POUR checklist)

Perceivable

• Non-text content has a text alternative; decorative images are hidden from AT.
• Text contrast ≥ 4.5:1; non-text (icons, borders, focus rings) ≥ 3:1.
• Layout reflows at 320px / 400% zoom without horizontal scroll or loss of content.

Operable (keyboard is the big one)

• Every control is reachable AND operable by keyboard (Enter/Space activate; arrows where expected).
• Focus is always visible.
• Focus order is logical and matches visual order.
• No keyboard trap — test Shift+Tab too, not just Tab. Focus can always move out of a widget both ways.
• Disabled controls are not in the tab order.
• Composite widgets (grid/tree/listbox/menu/tablist) are ONE logical tab stop with a roving tabindex; arrows move within.
• After async transitions (route change, panel open/close) focus lands somewhere useful, never silently on <body>.

Understandable

• Inputs have programmatic labels; visible label matches accessible name.
• Errors are identified in text and associated with their field; give a suggestion when possible.
• The same control is identified consistently across the app.

Robust (name / role / value)

• Interactive elements expose a correct role, name, and state.
• Valid ARIA parent/child (e.g. rowgroup owns row, list owns listitem).
• No tabbable element with a non-widget role (presentation/none).
• aria-hidden="true" never wraps a focusable element.

axe vs IBM: known gaps

Things axe passes but IBM flags (all real WCAG Level 1):

Rule of thumb: touch a table/tree/listbox/menu → scan with IBM.

Component Gotchas

• Data grids (AG Grid — the shared TableComponent): the grid's own tab guards + pagination are the fragile part.
  • Disabled paging buttons must be tabindex="-1", but NEVER inert/disabled — that breaks AG Grid's tab guards and traps reverse (Shift+Tab) entry (WCAG 2.1.2).
  • AG Grid still programmatically focuses disabled paging on tab-out; handle with its tabToNextCell hook plus a container-scoped focusin redirect (defer the redirect to requestAnimationFrame — focus changes inside a focusin handler are ignored, and AG Grid restores the last-focused cell on the next tick).
  • Empty rowgroups need role="presentation"; the grid needs one roving-tabindex row.
  • Icon-only / action column header: AG Grid derives the columnheader accessible name from field; a column with neither field nor headerName is nameless (aria_accessiblename_exists, 4.1.2). Give it a headerName and hide it visually with a headerClass (sr-only clip on .ag-header-cell-text) so the header stays blank but named.
  • Interactive control inside a cell (menu trigger, button): AG Grid navigates cell-by-cell and never tab-focuses the inner control, so it's keyboard-inoperable. Activate it from the grid's onCellKeyDown on Enter/Space (give the column a colId to target it). A Radix trigger opens on keydown/pointerdown, not a synthetic .click() — focus the trigger and re-dispatch the key (new KeyboardEvent("keydown", {key, bubbles:true})), guarding against re-entry (skip when target is already the button). TableComponent spreads {...props} to AG Grid, so pass onCellKeyDown from the page — no shared-component change.
  • Focus visible on borderless grids (.ag-no-border): the theme suppresses the cell focus outline (outline:none), hiding keyboard focus (2.4.7). Restore it with a :focus-visible ring scoped to .ag-no-border .ag-cell:focus-visible (+ header/row). :focus-visible distinguishes modality on AG cells — mouse click resolves to :focus, keyboard nav to :focus-visible — so the ring shows for keyboard only and mouse stays quiet. CAVEAT when verifying: probe with a clean, first-interaction page; a session that already used the keyboard makes :focus-visible report true for a later mouse click (heuristic contamination).
  • Set ensureDomOrder: true so DOM order matches visual order for tab navigation.
  • TableComponent is shared across settings/traces — fix once in the grid patch, then re-scan every grid page. Its pagination/tab-out rework lives in LE-1720 / PR #13953; don't duplicate it per-page.
• Modals/drawers: title + description, focus trapped inside while open, focus restored to the trigger on close, Escape closes.
• Dropdowns/popovers: reachable by keyboard, Escape closes, focus returns to the trigger.
• Radix (shadcn) primitives — three recurring traps:
  • Trigger asChild double tab stop: a DialogTrigger/DropdownMenuTrigger wrapping a real <button> without asChild makes Radix render its own <button> around it → nested buttons → two consecutive tab stops (2.4.3). Always pass asChild when the child is already an interactive element. (Watch the trigger wrapper's own asChild={cond} default — DeleteConfirmationModal needs an explicit asChild.)
  • Focus-restore race: on close, Radix restores focus to its trigger once, asynchronously. If the menu action programmatically moves focus elsewhere (e.g. startEditingCell opens an inline editor), Radix steals it back. Re-assert focus on your target across a few requestAnimationFrames to outlast the one-time restore. For rename-style flows, .select() the input too.
  • Portaled menu landmark: DropdownMenu/Popover content portals to <body>, tripping aria_content_in_landmark. Portaling into <main> is not an option when <main> is overflow-hidden (clips the menu). Treat as app-wide debt → baseline it (below); the menu's real a11y (role, named trigger, keyboard open/close, focus restore) is covered by a keyboard test instead.
• Disabled controls: keep them out of the tab order. Only use aria-disabled (instead of native disabled) when the control must stay discoverable, and keep it non-operable.
• Icon-only buttons: real <button> with an aria-label.
• Custom clickable divs/cells: prefer a semantic element; if a cell/card must open something it needs Enter/Space handling, not just onClick.

Best practices (settings grids + modals)

Apply these when building or reviewing AG Grid tables that open an edit modal (reference: GlobalVariablesPage, tests/a11y/global-variables.a11y.spec.ts):

• Keyboard map on selectable rows: Space toggles the row checkbox; Enter opens the row’s edit/detail UI. Do not use Space to open the modal.
• Scope the map on the page: implement with page-level onCellKeyDown and per-column suppressKeyboardEvent for Enter/Space so AG Grid’s default Space handling does not compete. Prefer not changing shared TableComponent defaults unless the same map is product-wide.
• Keep selection UI in sync: after node.setSelected, update React selection state so toolbar actions (e.g. delete) enable/disable correctly (TableOptions.hasSelection is read at render time).
• Retain place on modal close (2.4.3): remember the focused cell (rowIndex + colId) when opening edit; on close (Escape, Cancel, or save) restore with api.setFocusedCell + DOM .focus(), using a few requestAnimationFrames to outlast Radix dialog cleanup. Controlled edit dialogs without a Radix trigger need this explicitly. Create flows that use a real DialogTrigger (e.g. Add New) should restore to that trigger.
• Verify with keyboard tests: open from a cell → Escape → focus is still on that cell; Enter can open again without a mouse re-click.

Choose Test Layer

Jest + axe

Use Jest when the changed surface is a primitive or component that renders in jsdom without full app routing.

import { render, screen } from "@testing-library/react";
import { axe } from "@/utils/a11y-test";

it("should_have_no_axe_violations", async () => {
  const { container } = render(<Component />);
  expect(await axe(container)).toHaveNoViolations();
});

Notes: a11y-test.ts disables color-contrast (jsdom can't measure layout). Prefer role/label/text queries. Assert accessible names explicitly for icon-only / visually-hidden / generated labels. Put tests at __tests__/<name>.a11y.test.tsx.

cd src/frontend
npx jest path/to/<name>.a11y.test.tsx --runInBand

Playwright + page.runA11yScan

Use Playwright when the surface needs real browser layout, routing, app state, mocking, modals, tables, focus order, keyboard behavior, or full-page interactions.

import { expect, test } from "../fixtures";
import { awaitBootstrapTest } from "../utils/await-bootstrap-test";

test("scans populated state", { tag: ["@release", "@api"] }, async ({ page }) => {
  await awaitBootstrapTest(page, { skipModal: true });
  await page.goto("/settings/example");
  await expect(page.getByText("Example")).toBeVisible();
  await page.runA11yScan("settings-example-populated");
});

Rules: put specs under tests/a11y/<feature>.a11y.spec.ts; import test/expect from ../fixtures; tag every test @release plus a domain tag (@workspace/@api/@database/@components/@starter-projects); stable scan names (lowercase, feature-first, state-specific); mock API for deterministic states; disable animations for focus assertions; use explicit interactions (no random clicking of destructive controls). If the route belongs in static coverage, update scripts/a11y/a11y_routes.json.

cd src/frontend
RUN_A11Y=true npx playwright test tests/a11y/<feature>.a11y.spec.ts --project=chromium --workers=5
RUN_A11Y=true RUN_A11Y_ASSERT=true npx playwright test tests/a11y/<feature>.a11y.spec.ts --project=chromium --workers=5
npm run a11y:html-report --silent

IBM baselines (accepting known debt)

Some IBM violations are real but framework-level and can't be fixed per-page (e.g. aria_content_in_landmark on a Radix menu portal). Track them with an IBM baseline so the scan stays green while the debt is recorded — do NOT silently drop the scan or the assertion.

How it works (fixtures.ts + .achecker.yml):

• baselineFolder: tests/a11y/baselines. The baseline file name is the scan label: {project}__{label}.json, e.g. chromium__assets-files-actions-menu.json (dashes preserved; the first scan in a test has no index suffix).
• On each run IBM's filterReport loads that file and marks any result matching a baseline entry by path.dom + ruleId + reasonId as ignored: true. countNewA11yViolations counts violation && !ignored, so baselined issues don't fail.

Create one:

1. Run the scan once — it writes the full report to coverage/accessibility-reports/{label}.json.
2. Copy the offending result(s) into tests/a11y/baselines/{label}.json as { "results": [ { "ruleId", "reasonId", "path": { "dom": … } } ] }. A minimal baseline (only the entries to ignore) is clearest; add a description field noting why and how to resurface it.
3. Re-run → the scan passes. Commit the baseline so the debt is tracked; deleting it resurfaces the violation. Point at the baseline from a comment in the spec.

Matching is exact-DOM-path, so baselines can go stale if unrelated <body>-level portals (toasts) shift the portal index — scan the state with no other overlays open.

Route/Page Coverage Matrix

For route/page changes, cover the smallest matrix representing real user states:

• Loaded/default, empty data, populated data
• Primary modal open, dropdown/popover open
• Validation or error visible
• Selected/expanded table row or bulk-action state
• Mobile viewport when responsive layout changes

Don't force states the page can't enter; briefly explain any skipped state.

Data-Rich Route Pattern

Use tests/a11y/api-keys.a11y.spec.ts and tests/a11y/files.a11y.spec.ts as the models for route-level work: mock API data; scan populated table; scan empty table; open create modal and scan; submit to the generated-result modal and scan; open a text-cell modal and scan; select a row and scan the selected state; set a mobile viewport and scan. Add keyboard-interaction tests (not scans) for tab-out, reverse re-entry, Enter-to-open, focus restore, and focus-visible where the surface has custom keyboard behavior. This is the expected bar for data-rich routes.

Driving grid row states: client-rendered states (upload progress %, upload-failed/error, disabled rows) are usually driven by fields the cell renderer reads off the row (params.data.*). If the list query returns the response untransformed, just inject the field into the mocked rows (e.g. { ...file, progress: -1 }) to scan the error/progress state — no need to simulate the real flow.

Report Back

When done, state:

• Test files added or updated, and states scanned.
• Commands run — including whether BOTH axe and IBM were run and both reported zero.
• Any states not covered and why.
• Any remaining a11y risk or accepted limitation.