`react-doctor/no-unguarded-browser-global-at-module-scope`

Browser global read at module scope

Category: Bugs
Severity: warn
Source: oxlint-plugin-react-doctor
Framework: global
Enabled when: ssr
Default: Enabled

Validate the diagnostic

Confirm the reported code matches this rule before you edit it.

Confirm the reported code matches react-doctor/no-unguarded-browser-global-at-module-scope. 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

const theme = localStorage.getItem("theme");

Corrected pattern

const readTheme = () =>
  typeof window === "undefined" ? null : localStorage.getItem("theme");

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 react-doctor/no-unguarded-browser-global-at-module-scope diagnostic in the current repository. Required change: - Reading window/navigator/localStorage at module scope throws ReferenceError: window is not defined when the module is imported during SSR. Move the read inside a function/effect, or guard it with typeof window !== "undefined".

Reference transformation:Before:

const theme = localStorage.getItem("theme");

After:

const readTheme = () =>
  typeof window === "undefined" ? null : localStorage.getItem("theme");

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. - 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: ssr. 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.

More Bugs rules from the rules reference:

react-doctor/no-unguarded-browser-global-in-render-or-hook-init: Browser global read during server render
react-doctor/no-unguarded-numeric-input-parse: Unguarded numeric parse of an input value
react-doctor/no-unguarded-throwing-parse-call: Unguarded call to a throwing parse API
react-doctor/no-unknown-property: Disallow unknown or mis-cased DOM attributes in JSX, like class instead of className.
react-doctor/no-unsafe: Replace UNSAFE_componentWillMount / WillReceiveProps / WillUpdate with their modern lifecycle equivalents.

react-doctor/no-unguarded-browser-global-at-module-scope