react-doctor/html-xml-lang-mismatch
Conflicting document language declarations
- Category: Accessibility
- Severity: warn
- Source:
oxlint-plugin-react-doctor - Framework: global
- Enabled when: react
- Default: Disabled until configured
Validate the diagnostic
Confirm the reported code matches this rule before you edit it.
Confirm the reported code matches react-doctor/html-xml-lang-mismatch. Compare it with the Before example and verify the same API, framework, and execution context. Treat it as a false positive only when one of those conditions differs.
Compare the code
The corrected pattern shows a focused way to address the diagnostic.
Reported pattern
<html lang="en-US" xml:lang="fr" />Corrected pattern
<html lang="en-US" xml:lang="en-US" />How to fix
Use the corrected pattern as a reference. Preserve behavior that the rule does not require you to change.
Copyable fix prompt
Copy this self-contained prompt into your coding agent after you confirm the diagnostic.
Fix every confirmed
Reference transformation:Before:react-doctor/html-xml-lang-mismatch diagnostic in the current repository.
Required change:
- Use matching base languages for lang and xml:lang on the root html element.<html lang="en-US" xml:lang="fr" /><html lang="en-US" xml:lang="en-US" />Constraints:
- Confirm the reported code matches the Before pattern.
- Make the smallest change that fixes the root cause.
- Preserve behavior and interfaces unrelated to this diagnostic.
- Reuse existing project components, utilities, and conventions.
- Do not introduce render-phase side effects, render-phase state updates, or Hooks rule violations.
- Preserve accessible names, focus order, keyboard behavior, and touch access not targeted by this rule.
- Adapt identifiers and framework details instead of copying blindly.
- Do not disable the rule or suppress matching code.
- Confirm this rule is enabled for the project:
react.
Verification:
- Run focused tests for the changed behavior.
- Run React Doctor and confirm this diagnostic no longer appears.
- Report the files changed and any checks you could not run.Related rules
More Accessibility rules from the rules reference:
react-doctor/iframe-has-title: Require a unique, descriptive title attribute on iframes so assistive-tech users can identify embedded content.react-doctor/iframe-title-unique: Frame title is duplicatedreact-doctor/img-redundant-alt: Drop redundant words like 'image' / 'photo' / 'picture' from alt text and describe the content instead.react-doctor/ink-valid-aria-semantics: Invalid Ink accessibility semanticsreact-doctor/interactive-supports-focus: Add tabIndex to elements that have interactive roles and event handlers.