`react-doctor/no-eager-new-in-use-state-initializer`

Eager constructor in useState initializer

Category: Performance
Severity: warn
Source: oxlint-plugin-react-doctor
Framework: global
Enabled when: react
Tags: test-noise
Default: Enabled

Validate the diagnostic

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

Confirm the reported code matches react-doctor/no-eager-new-in-use-state-initializer. 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 { useState } from "react";

const ClientProvider = ({ children }) => {
  const [client] = useState(new ApiClient(config));
  return <ApiProvider client={client}>{children}</ApiProvider>;
};

Corrected pattern

import { useState } from "react";

const ClientProvider = ({ children }) => {
  const [client] = useState(() => new ApiClient(config));
  return <ApiProvider client={client}>{children}</ApiProvider>;
};

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-eager-new-in-use-state-initializer diagnostic in the current repository. Required change: - Wrap nontrivial construction in a function (useState(() => new X())) so it only runs on the first render.

Reference transformation:Before:

import { useState } from "react";

const ClientProvider = ({ children }) => {
  const [client] = useState(new ApiClient(config));
  return <ApiProvider client={client}>{children}</ApiProvider>;
};

After:

import { useState } from "react";

const ClientProvider = ({ children }) => {
  const [client] = useState(() => new ApiClient(config));
  return <ApiProvider client={client}>{children}</ApiProvider>;
};

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. 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/no-ease-in-motion: UI motion starts with ease-in
react-doctor/no-excessive-motion-stagger: Motion child stagger is too long
react-doctor/no-flush-sync: Use startTransition for non-urgent updates — flushSync forces a sync flush that skips View Transitions and concurrent rendering
react-doctor/no-full-lodash-import: Import the specific function: `import debounce from 'lodash/debounce'` — saves ~70kb
react-doctor/no-global-css-variable-animation: Set the variable on the nearest element instead of a parent, or use `@property` with `inherits: false` to prevent cascade. Better yet, use targeted `element.style.transform` updates

react-doctor/no-eager-new-in-use-state-initializer