TypeError: Cannot read properties of undefined (reading 'clone')

[preetish-brine]

Error Details

• Level: Error
• Cannot read properties of undefined (reading 'clone')
• Location: (@reduxjs/toolkit/dist/query/rtk-query.esm)

Source Map

../../node_modules/@reduxjs/toolkit/dist/query/rtk-query.esm.js in at line 269:46
../../node_modules/@reduxjs/toolkit/dist/query/rtk-query.esm.js in step at line 23:23
../../node_modules/@reduxjs/toolkit/dist/query/rtk-query.esm.js in Object.next at line 4:53
../../node_modules/@reduxjs/toolkit/dist/query/rtk-query.esm.js in fulfilled at line 70:32

Our Setup
We’re using:

const baseQueryWithSessionHandler = async (args, api, extraOptions) => {
  ...
  const result = await baseQuery(adjustedArgs, api, extraOptions);
    if (result.data) {
      result.data = { ...result.data, statusCode: result.meta.response.status };
      return result;
    }
  ...
};

Wrapped in retry() and custom backoff:

const staggeredBaseQueryWithSessionHandler = retry(baseQueryWithSessionHandler, {
  backoff: customBackoff,
  maxRetries: 3,
  retryCondition: (error, args, { baseQueryApi, attempt }) => {
    return (
      args.method === 'GET' &&
      attempt < 3 &&
      error?.data?.message !== unauthorizedErrorMessage &&
      error?.status !== 401
    );
  },
});

After digging into the source of fetchBaseQuery and retry, we observed:
meta is created and initially populated with request:

requestClone = request.clone();
meta = { request: requestClone };
Later, only if fetch() succeeds, response.clone() is called and attached to meta.response.

responseClone = response.clone();
meta.response = responseClone;
If the initial fetch fails (e.g. due to network or DNS issues), then meta.response is never set.

If a subsequent retry succeeds, the returned result includes data, but meta.response may still be missing

[markerikson]

Can you provide a sandbox or repo that reproduces this issue? Seems extremely odd that there isn't a response here.

[preetish-brine]

https://codesandbox.io/p/sandbox/6lsqsm here is a sandbox @markerikson please check this and get back

[markerikson]

@preetish-brine I'm looking at the sandbox example app and I don't see any errors like this. Are there specific steps to reproduce? Does this demo actually show the error, or is it "just" the code you're using but the demo works fine?

[preetish-brine]

this just the code that we are using in the same flow exactly, this error is random and comes randomly the behaviour is very random hence its concerning @markerikson

[markerikson]

Any chance you could put together an updated version that actually shows this error happening with some consistency? Just based on that retry bit I can't see anything that seems like it would affect RTKQ's internals.

[markerikson]

Hmm. Actually, I missed reading the section about "if the fetch fails, meta.response isn't set". That seems plausible.

[markerikson]

Okay, yeah, I can see that if I force the fetchFn to return something that isn't a Response, the response.clone() line fails. However, that whole block of logic is written under the assumption that it did return a Response.

Can you give a working example of cases where fetch doesn't return a Response?

[preetish-brine]

This happens only a few times a day among many user sessions, so it’s almost certainly due to transient network instability rather than a deterministic code bug. It’s not reproducible in a controlled environment.

[markerikson]

We talked about this a bit, and the thing is that fetch is defined as returning Promise<Response>. If that's not happening, then it's a bug in the fetching function. We could technically check for it to return something else, but that shouldn't be happening.

Can you reproduce this at all without the retry behavior? Or describe a way to make this happen consistently?

Right now my inclination is to say "we rely on the spec here, and any violations of that are not a bug in RTK".

[preetish-brine]

Updated methods to make the sandbox support retry as well as random null responses , check index.tsx and comment / uncomment methods based on usage. https://codesandbox.io/p/sandbox/6lsqsm but yet to replicate this behaviour