Include required ARIA attributes for roles

Rule Details

ARIA roles often have mandatory attributes that must be present for the element to be considered valid and accessible.

Code Example

<!-- Correct Slider implementation -->
<div role="slider"
     aria-valuenow="50"
     aria-valuemin="0"
     aria-valuemax="100"
     aria-label="Volume level">
</div>
 
<!-- Correct Scrollbar implementation -->
<div role="scrollbar"
     aria-controls="content-id"
     aria-orientation="vertical"
     aria-valuenow="25"
     aria-valuemin="0"
     aria-valuemax="100">
</div>

Why It Matters

• Functional Integrity: Many roles are non-functional without their supporting attributes.
• Accurate Communication: Screen readers rely on these attributes to announce the current state (e.g., the current value of a slider).
• Spec Compliance: Adheres to the W3C ARIA standard, ensuring better cross-browser accessibility.
• User Control: Allows users to understand the boundaries (min/max) and current state of interactive controls.

Exceptions

• Prefer native HTML semantics over ARIA when both are possible; some apparent ARIA failures disappear when the underlying element is corrected.
• A missing ARIA attribute is not automatically the strongest finding if the control is already semantically broken, unnamed, or keyboard-inaccessible.
• Do not add ARIA only to satisfy the rule if the feature should instead be implemented with a native element or a simpler interaction pattern.

Standards

• Align the implementation with WAI-ARIA 1.2 and verify the rendered experience, not only the source code.
• Align the implementation with MDN: ARIA and verify the rendered experience, not only the source code.

Verification

Automated Checks

• Inspect the browser accessibility tree or accessibility pane for the relevant element, role, or accessible name.
• Run an automated accessibility checker such as axe or Lighthouse where applicable.

Manual Checks

• Test the affected UI with keyboard-only navigation and confirm the rule holds in the rendered experience.
• Re-test one representative user flow with a screen reader if this rule affects a key interaction.