ErrorMessageAssociated [check] v1.0.0

Validates that form-error messages are programmatically associated with their failing inputs via aria-describedby + role='alert' (or aria-live), and that aria-invalid='true' is set on the visually-errored input.

signature: (html: string, context?: object) -> CheckResult predicate: // Error messages must be programmatically associated with the failing field via: // 1. aria-describedby on the input pointing to the error element id // 2. Error element has role="alert" or aria-live="assertive" for screen-reader announce // 3. Input has aria-invalid="true" when error is shown invalidInputs = querySelectorAll('input[aria-invalid="true"], textarea[aria-invalid="true"], select[aria-invalid="true"], .input--error, [data-state="error"]') for i in invalidInputs: // 1. aria-describedby must point to existing element descId = i.getAttribute('aria-describedby') if !descId: yield { selector: cssPath(i), fail: 'invalid-input-no-describedby' } continue

// Multiple ids allowed (space-separated) ids = descId.split(/\s+/) missing = ids.filter(id => !document.getElementById(id)) if missing.length > 0: yield { selector: cssPath(i), fail: 'describedby-target-missing', missing } continue

// 2. At least one referenced element should be the error message with role/live errorEl = ids.map(id => document.getElementById(id)).find(el => el.getAttribute('role') === 'alert' || el.getAttribute('aria-live') === 'assertive' || el.getAttribute('aria-live') === 'polite' ) if !errorEl: yield { selector: cssPath(i), fail: 'no-live-error-region', describedby: descId, remedy: 'add role="alert" to the error span' }

// 3. aria-invalid must be present and "true" if i.getAttribute('aria-invalid') !== 'true' && /error/.test(i.className): yield { selector: cssPath(i), fail: 'visual-error-without-aria-invalid' }

// Also: error elements with role="alert" should be associated TO an input alerts = querySelectorAll('[role="alert"], [aria-live="assertive"]') for a in alerts: if !a.id: continue referrers = querySelectorAll([aria-describedby~="${a.id}"]) if referrers.length === 0 && a.textContent.trim() !== '': yield { selector: cssPath(a), fail: 'orphan-error-region', remedy: 'reference this id from input aria-describedby' }

Meta

• License: Apache-2.0
• License Provenance: package-authorship-claim

Validates

@community/rule-error-message-associated

Severity

high

Failure Message Template

Error association failure on '{selector}': {fail}. {remedy}. Without programmatic association, screen readers cannot link the error to the field.

Evaluation Method

automated

Tools

• axe-core
• @testing-library/dom
• playwright

False Positive Rate

low

ErrorMessageAssociated [check] v1.0.0

Validates that form-error messages are programmatically associated with their failing inputs via aria-describedby + role='alert' (or aria-live), and that aria-invalid='true' is set on the visually-errored input.

signature: (html: string, context?: object) -> CheckResult predicate: // Error messages must be programmatically associated with the failing field via: // 1. aria-describedby on the input pointing to the error element id // 2. Error element has role="alert" or aria-live="assertive" for screen-reader announce // 3. Input has aria-invalid="true" when error is shown invalidInputs = querySelectorAll('input[aria-invalid="true"], textarea[aria-invalid="true"], select[aria-invalid="true"], .input--error, [data-state="error"]') for i in invalidInputs: // 1. aria-describedby must point to existing element descId = i.getAttribute('aria-describedby') if !descId: yield { selector: cssPath(i), fail: 'invalid-input-no-describedby' } continue

// Multiple ids allowed (space-separated) ids = descId.split(/\s+/) missing = ids.filter(id => !document.getElementById(id)) if missing.length > 0: yield { selector: cssPath(i), fail: 'describedby-target-missing', missing } continue

// 2. At least one referenced element should be the error message with role/live errorEl = ids.map(id => document.getElementById(id)).find(el => el.getAttribute('role') === 'alert' || el.getAttribute('aria-live') === 'assertive' || el.getAttribute('aria-live') === 'polite' ) if !errorEl: yield { selector: cssPath(i), fail: 'no-live-error-region', describedby: descId, remedy: 'add role="alert" to the error span' }

// 3. aria-invalid must be present and "true" if i.getAttribute('aria-invalid') !== 'true' && /error/.test(i.className): yield { selector: cssPath(i), fail: 'visual-error-without-aria-invalid' }

// Also: error elements with role="alert" should be associated TO an input alerts = querySelectorAll('[role="alert"], [aria-live="assertive"]') for a in alerts: if !a.id: continue referrers = querySelectorAll([aria-describedby~="${a.id}"]) if referrers.length === 0 && a.textContent.trim() !== '': yield { selector: cssPath(a), fail: 'orphan-error-region', remedy: 'reference this id from input aria-describedby' }

Meta

• License: Apache-2.0
• License Provenance: package-authorship-claim

Validates

@community/rule-error-message-associated

Severity

high

Failure Message Template

Error association failure on '{selector}': {fail}. {remedy}. Without programmatic association, screen readers cannot link the error to the field.

Evaluation Method

automated

Tools

• axe-core
• @testing-library/dom
• playwright

False Positive Rate

low

Relations

related: [@community/rule-error-message-associated, @community/check-form-validation-inline, @community/pattern-inline-validation]

Meta

• License: Apache-2.0
• License Provenance: package-authorship-claim

Validates

@community/rule-error-message-associated

Severity

high

Failure Message Template

Error association failure on '{selector}': {fail}. {remedy}. Without programmatic association, screen readers cannot link the error to the field.

Evaluation Method

automated

Tools

• axe-core
• @testing-library/dom
• playwright

False Positive Rate

low