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Web Component Accessibility

Accessibility (a11y) patterns and remediation guidance for web components. Reference any time work involves the visible or interactive surface of a component — generating, modifying, reviewing, or styling HTML, JS, or CSS — to apply WCAG 2.2 standards.

Review Context

Conduct a review specifically focused on enhancing web accessibility, guided by the WCAG (Web Content Accessibility Guidelines).

In order to mark code as a violation, it must have a direct correlation to the WCAG rule cited such that it is a clear violation of the criteria.

Key Review Criteria:

1. Focus Exclusively on Accessibility:

• Evaluate the component solely for accessibility.
• Only consider compliance with the cited WCAG Success Criteria, ignoring violations that can be attributed to other criteria.
• Avoid addressing general code style, patterns, or issues unrelated to accessibility.

2. Ensure Minimum and Sufficient Accessibility:

• Identify accessibility issues that prevent the component from meeting the minimum requirements outlined by WCAG.
• Avoid suggesting enhancements that go beyond the scope of WCAG compliance unless strictly necessary.

3. WAI-ARIA Usage:

• Use WAI-ARIA attributes only when strictly required to achieve accessibility that cannot otherwise be addressed with semantic HTML.
• Avoid unnecessary complexity or potential regressions caused by incorrect or overuse of ARIA attributes.

4. Component Library Usage

• Assume that well-known component libraries (e.g., Salesforce Lightning, Material UI, Chakra UI) are accessible out of the box when correctly implemented. Unless they are used specifically in conflict with WCAG, library-provided components can be ignored for this review, as they are implemented in an accessible way beneath the abstraction.
• Lightning base components (lightning-input, lightning-combobox, lightning-textarea, lightning-icon, and similar components) provide accessible labeling, ARIA, and error handling through dedicated attributes such as label and alternative-text. A label remains programmatic even with variant="label-hidden"; do not require a sibling or wrapper <label> to target the component. Navigation, button-icon, and other self-labeling base components likewise expose supplied label text as their accessible name and treat their internal icon as decorative. Do not report a missing association merely because that implementation is hidden inside the component.
• The same self-labeling logic applies to imported or custom control components in any framework (React/JSX, Angular, Vue, Web Components), not only Lightning. A capitalized or imported component tag (<Input>, <TextField>, <Button>, <Select>, <Checkbox>, <SearchField>, and design-system wrappers from Material UI, Chakra, Radix, or an internal library) is not a bare HTML element — assume it renders its own accessible label, ARIA, and error handling beneath the abstraction (see the component-library grounding rule). When such a component is given a labeling prop — label, aria-label, aria-labelledby, title, or visible child text/children — treat it as already programmatically labeled and do not flag it for a missing <label>, a missing for/id association, or a missing accessible name. Only flag when no labeling prop or text is supplied, or the supplied value is clearly empty or nonsensical. Do not demand a native <label for> for a component whose internal control you cannot see.
• Resolve dynamic id / htmlFor / for expressions before judging a label association. When a <label htmlFor={X}> (or for={X}) and its control's id={X} are bound to the same expression — the same variable, prop, useId() value, or template literal (e.g. both htmlFor and id set to the same interpolation such as ${id}-email) — treat the association as matching, even though the literal string cannot be resolved at review time. A dynamic id/htmlFor pair is a mismatch only when the two expressions are demonstrably different. Do not flag identical dynamic id/htmlFor expressions as unmatched or mismatched labels.

5. Source Interpretation

• Resolve expressions according to the framework's binding semantics before judging them. Trace a dynamic value to every source available in that context. In React/JSX, an expression may reference local variables, props, hook results, or imported bindings; Vue, Svelte, and Astro expose their own template or script scopes. In an LWC template specifically, {someValue} resolves to a field, property, or getter on the component class (.js or .ts), including @api properties; module-level imported constants are not directly bindable. In Aura markup, follow the expression's value provider, such as v. or c., to the corresponding component attribute or controller logic. Do not conclude that a value is undefined, empty, or missing until you have inspected the applicable source. In a diff, verify which side contains the corrected code rather than assuming that the change introduced the problem.

Focus: Provide actionable feedback to ensure the component meets the necessary WCAG accessibility requirements, avoiding extraneous feedback unrelated to the prompt's scope. Identify issues in code only if there is an immediate fix. You MUST conduct the review, and subsequently suggest the code fix that solves this issue.

Success Criteria Reviewers

Identify which Success Criteria apply to the code under review, then open the reference files relevant to that code. Each reference supplies criterion-specific analysis, examples, and remediation guidance; the review-wide rules above continue to apply.

Perceivable

• SC 1.1.1 Non-text Content
• SC 1.3.1 (i) Lists
• SC 1.3.1 (ii) Tables
• SC 1.3.1 (iii) Form Labels
• SC 1.3.1 (iv) Regions
• SC 1.3.1 (v) Groups
• SC 1.3.5 Identify Input Purpose
• SC 1.4.3 Contrast (Minimum)

Operable

• SC 2.1.1 Keyboard
• SC 2.4.4 Link Purpose
• SC 2.4.6 Headings and Labels
• SC 2.5.1 Pointer Gestures
• SC 2.5.2 Pointer Cancellation
• SC 2.5.3 Label in Name
• SC 2.5.7 Dragging Movements

Understandable

• SC 3.2.1 On Focus
• SC 3.2.2 On Input
• SC 3.3.1 Error Identification
• SC 3.3.2 Labels or Instructions
• SC 3.3.3 Error Suggestion

Robust

• SC 4.1.2 (i) Name
• SC 4.1.2 (ii) Role
• SC 4.1.2 (iii) Value

Vision-Assisted Review

When component screenshots or design mocks are available, augment the source-code review with these vision-level reviewers. Each reference covers image-based evaluation for the corresponding Success Criterion — contrast ratios, color dependence, resize/reflow behavior, and non-text content identification from pixels rather than from the DOM.

• SC 1.1.1 Non-text Content (vision)
• SC 1.4.1 Use of Color (vision)
• SC 1.4.3 Contrast (vision)
• SC 1.4.10 Reflow (vision)
• SC 1.4.11 Non-text Contrast (vision)

Review Output

For each Success Criterion you evaluated, report violations found. If no violations exist for a criterion, return an empty list for that criterion.