[test][checkbox] Add axe tests and WCAG conformance report

[michelengelen]

Adds axe coverage and the WCAG 2.2 Level A/AA conformance report for Checkbox.

Result	Count
✅ Supports	22
⚠️ Partially Supports	3
❌ Does Not Support	0
➖ Not Applicable	30

Known gaps: focus-indicator contrast and custom icons below 3:1 (1.4.11), disableRipple removing the focus indicator (2.4.7), and indeterminate setting aria-checked="mixed" on a native checkbox whose checked is false (4.1.2) — the one genuine defect in the series.

Report: Checkbox/accessibility.md

Important

How to review this PR

Layer 5 of 14 in a stacked series (#48915 → #48926). Its branch is built on a11y/stack/avatar (#48917). GitHub cannot chain PR bases across a fork, so every PR in the series targets master instead.

Review only the last commit — 2ee61e1. Everything above it belongs to the layers below, and disappears as those merge.

Original work by @mj12albert. Supersedes #48734, rebased onto current master.

Part of the WCAG conformance effort (#14187).

[code-infra-dashboard]

Deploy preview

• docs/data/material/components/checkboxes/checkboxes.a11y.json

  
  

Bundle size

Bundle	Parsed size	Gzip size
@mui/material	0B(0.00%)	0B(0.00%)
@mui/lab	0B(0.00%)	0B(0.00%)
@mui/private-theming	0B(0.00%)	0B(0.00%)
@mui/system	0B(0.00%)	0B(0.00%)
@mui/utils	0B(0.00%)	0B(0.00%)

Details of bundle changes

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Check out the code infra dashboard for more information about this PR.

[michelengelen]

PR review

Clean PR. The IndeterminateCheckbox skip is the right call — the aria-conditional-attr hit is a real, documented gap of the component, and the rule records it in the JSON instead of hiding it. One weak test title.

Tests (1)

1. 🟡 Test title claims more than it asserts

Location: packages/mui-material/src/Checkbox/Checkbox.test.js:424

it('reflects the checked state and notifies on change', async () => {

The test asserts only the checked flip after user.click. No change handler is asserted, so the "notifies on change" half of the name is untested here (it is covered by the 2.1.1 test, but under a different claim).

Failure scenario: an onChange regression passes this test while its name says the notification is verified.

Fix: assert a spy's call count, or rename the test to "reflects the checked state".

Verdict

Approve after nits - solid coverage; one test name to align with its assertions.

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🤖 Review generated with Claude Code