`react-doctor/react-router-server-middleware-return-response`

Server middleware drops the Response

Category: Bugs
Severity: error
Source: oxlint-plugin-react-doctor
Framework: global
Enabled when: react-router:7.9, react-router-framework
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/react-router-server-middleware-return-response. 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

export const middleware = [async (_, next) => {
  const response = await next();
  response.headers.set("X-Trace", traceId);
}];

Corrected pattern

export const middleware = [async (_, next) => {
  const response = await next();
  response.headers.set("X-Trace", traceId);
  return response;
}];

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/react-router-server-middleware-return-response diagnostic in the current repository. Required change: - Return the Response produced by next(), or return an explicit replacement Response.

Reference transformation:Before:

export const middleware = [async (_, next) => {
  const response = await next();
  response.headers.set("X-Trace", traceId);
}];

After:

export const middleware = [async (_, next) => {
  const response = await next();
  response.headers.set("X-Trace", traceId);
  return response;
}];

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: react-router:7.9, react-router-framework. 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/react-router-session-mutation-requires-commit: Session mutation is not committed
react-doctor/react-router-valid-route-object: Contradictory route object
react-doctor/remotion-calculate-metadata-fetch-signal: calculateMetadata fetch ignores abortSignal
react-doctor/remotion-deterministic-randomness: Randomness changes between rendered frames
react-doctor/remotion-no-css-animation: CSS animation is not frame-driven

react-doctor/react-router-server-middleware-return-response