Mark inputs with a required() validator as aria-required

[ousamabenyounes]

Problem

When an input uses a required() validator (e.g. <TextInput source="id" validate={required()} />), react-admin adds the * to the label but leaves the underlying <input> without any required semantics. As a result:

• Assistive technologies do not announce the field as required.
• Tests can't assert it: expect(within(edit).getByLabelText('Id *')).toBeRequired() fails.

This was reported in #9585. As discussed there, the fix should use aria-required="true" rather than the native required attribute: react-admin relies on JS validation, and forms render with noValidate=false by default, so a native required attribute would trigger native browser validation. Adding aria-required was the explicit direction given by the maintainer on the issue.

Solution

Route an aria-required flag through the shared ResettableTextField renderer onto the native <input> element, and have TextInput pass aria-required={isRequired || undefined} (where isRequired already reflects the presence of a required() validator or the isRequired prop).

• The value is applied to the html-input slot only, handling both MUI v5 (inputProps) and MUI v6+ (slotProps.htmlInput, including the callback form).
• Caller-supplied inputProps / slotProps.htmlInput are preserved (non-lossy merge).
• Strictly a no-op when the input is not required (no attribute is added).
• The native required attribute is intentionally not set, so JS validation and label behavior are unchanged.

Scope: this PR fixes the reported TextInput case via the shared ResettableTextField. The same one-line aria-required={isRequired || undefined} wiring can be extended to the other inputs that expose isRequired (SelectInput, NumberInput, DateInput, …) — happy to widen this PR or open a follow-up, whichever the maintainers prefer.

How To Test

<TextInput source="id" validate={required()} /> now renders <input ... aria-required="true"> (and still no native required). A non-required input is unchanged.

Unit test added in TextInput.spec.tsx:

describe('aria-required', () => {
  it('should mark the input as required with aria-required (not the native required attribute) when a required() validator is set', ...)
  it('should not mark the input as required when no required validator is set', ...)
  it('should preserve caller-provided inputProps while adding aria-required', ...)
})

Test verification (RED → GREEN)

RED — on the unmodified next branch (test kept, production change reverted):

aria-required
  ✕ should mark the input as required with aria-required (not the native required attribute) when a required() validator is set
  ✓ should not mark the input as required when no required validator is set
  ✕ should preserve caller-provided inputProps while adding aria-required

  ● should mark the input as required ... › expect(element).toBeRequired()
    Received element is not required:
      <input aria-describedby=":r0:-helper-text" aria-invalid="false" id=":r0:" name="title" type="text" value="" />

Tests: 2 failed, 12 skipped, 1 passed, 15 total

GREEN — with the fix:

aria-required
  ✓ should mark the input as required with aria-required (not the native required attribute) when a required() validator is set
  ✓ should not mark the input as required when no required validator is set
  ✓ should preserve caller-provided inputProps while adding aria-required

Tests: 82 passed, 82 total

No regression across the shared renderer's consumers (TextInput, SelectInput, NumberInput suites all green); ESLint, Prettier, and the ra-core → ra-ui-materialui build all pass.

Additional Checks

• The PR targets master for a bugfix or a documentation fix, or next for a feature — targets next as requested on the issue.
• The PR includes unit tests.
• The PR includes one or several stories — no new story: aria-required is a non-visual accessibility attribute and existing required stories (TextInput.stories.tsx, useInput.stories.tsx) already cover the required rendering. Happy to add one if preferred.
• The documentation is up to date — the docs already recommend the aria-required={isRequired} pattern (docs_headless/.../Inputs.md, useInput.md); this makes the built-in TextInput conform, so no doc file drifts.