`react-doctor/context-provider-value-from-unmemoized-local-literal`

Context value from an unmemoized local literal

Category: Performance
Severity: warn
Source: oxlint-plugin-react-doctor
Framework: global
Enabled when: react
Tags: react-jsx-only, test-noise
Disabled when: react-compiler
Default: Enabled

Validate the diagnostic

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

Confirm the reported code matches react-doctor/context-provider-value-from-unmemoized-local-literal. 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

import { createContext } from "react";
const ThemeContext = createContext(null);
const App = ({ theme }) => {
  const value = { theme };
  return <ThemeContext.Provider value={value}><Child /></ThemeContext.Provider>;
};

Corrected pattern

import { createContext, useMemo } from "react";
const ThemeContext = createContext(null);
const App = ({ theme }) => {
  const value = useMemo(() => ({ theme }), [theme]);
  return <ThemeContext.Provider value={value}><Child /></ThemeContext.Provider>;
};

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/context-provider-value-from-unmemoized-local-literal diagnostic in the current repository. Required change: - Memoize the context value in component scope so consumers do not redraw every render. For mapped providers, extract each item into a child component and memoize there.

Reference transformation:Before:

import { createContext } from "react";
const ThemeContext = createContext(null);
const App = ({ theme }) => {
  const value = { theme };
  return <ThemeContext.Provider value={value}><Child /></ThemeContext.Provider>;
};

After:

import { createContext, useMemo } from "react";
const ThemeContext = createContext(null);
const App = ({ theme }) => {
  const value = useMemo(() => ({ theme }), [theme]);
  return <ThemeContext.Provider value={value}><Child /></ThemeContext.Provider>;
};

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 resource ownership and cleanup. Do not move work into a hotter render or frame path. - 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. - Do not edit code when this condition applies: react-compiler. 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 Performance rules from the rules reference:

react-doctor/ink-prefer-use-animation: Animation loop implemented with setInterval
react-doctor/js-async-reduce-without-awaited-acc: Await the accumulator inside an async .reduce reducer: const acc = await previous; ...; return acc;
react-doctor/js-batch-dom-css: Batch DOM/CSS reads and writes — interleaving them inside a loop causes layout thrashing. Read first, then write
react-doctor/js-cache-property-access: Hoist the deep member access into a const at the top of the loop body: `const { x, y } = obj.deeply.nested`
react-doctor/js-cache-storage: Cache repeated `localStorage`/`sessionStorage` reads in a local variable — each access serializes/deserializes

react-doctor/context-provider-value-from-unmemoized-local-literal