remix: Cannot cancel a stream that already has a reader

What version of Remix are you using?

1.6.7

Steps to Reproduce

I’m executing a http request from a route Action but I’m getting this error because Server is busy (not responding):


[frontend] /frontend/node_modules/web-streams-polyfill/src/lib/readable-stream.ts:149
[frontend]       return promiseRejectedWith(new TypeError('Cannot cancel a stream that already has a reader'));
[frontend]                                  ^
[frontend] TypeError: Cannot cancel a stream that already has a reader
[frontend]     at ReadableStream.cancel (/frontend/node_modules/web-streams-polyfill/src/lib/readable-stream.ts:149:34)
[frontend]     at abort (/frontend/node_modules/@remix-run/web-fetch/src/fetch.js:75:18)
[frontend]     at AbortSignal.abortAndFinalize (/frontend/node_modules/@remix-run/web-fetch/src/fetch.js:91:4)
[frontend]     at AbortSignal.[nodejs.internal.kHybridDispatch] (node:internal/event_target:643:20)
[frontend]     at AbortSignal.dispatchEvent (node:internal/event_target:585:26)
[frontend]     at abortSignal (node:internal/abort_controller:284:10)
[frontend]     at AbortController.abort (node:internal/abort_controller:315:5)
[frontend]     at Timeout._onTimeout (/frontend/apps/webapp/app/utils/http.ts:16:42)
[frontend]     at listOnTimeout (node:internal/timers:559:17)
[frontend]     at processTimers (node:internal/timers:502:7)

I created a simple utility to support timeout with fetch:

const DEFAULT_TIMEOUT = 5000;

export type HttpOptions = RequestInit & {
  timeout?: number;
  defaultResponse?: unknown;
  parseJSON?: boolean;
}

async function httpRequest(
  resource: string,
  options: HttpOptions = { timeout: DEFAULT_TIMEOUT, parseJSON: true },
) {
  const { timeout, ...rest } = options;
  
  const controller = new AbortController();
  const id = setTimeout(() => controller.abort(), timeout || DEFAULT_TIMEOUT);
  try {
    const response = await fetch(resource, {
      ...rest,
      signal: controller.signal
    });
    clearTimeout(id);
    return rest.parseJSON === false ? response : response.json();
  } catch (error) {
    if (rest.defaultResponse !== undefined) {
      return rest.defaultResponse;
    }
    if (controller.signal.aborted) {
      throw new Error('Server is busy, please try again');
    }
    throw error;
  }
}

export { httpRequest };

Then I’m using that method to execute a POST request:

export const action: ActionFunction = async ({ request }) => {
  const formData = await request.formData();

  const email = formData.get('email');
  try {
    await httpRequest(`${apiURL}/auth`, {
      method: 'POST',
      body: JSON.stringify({
        email,
      }),
      parseJSON: false,
    });

    // ...
  } catch (error) {
    return {
      error: (error as Error)?.message,
    }
  }
};

Also I’m already using CatchBoundary and ErrorBoundary for this page:

function renderLoginPage(error?: Error) {
  const data = useLoaderData();
  return (
    <div id="main-content" className="relative pb-36">
      <LoginPage {...data} error={error} />
    </div>
  );
}

export const CatchBoundary = () => {
  const caught = useCatch();
  return renderLoginPage(caught.data);
};

export const ErrorBoundary: ErrorBoundaryComponent = ({ error }) => {
  return renderLoginPage(error);
};

export default function () {
  return renderLoginPage();
}

Expected Behavior

Be able to get the error message using useActionData Hook from Remix, it’s working for other validations before executing the HTTP request.

Actual Behavior

Getting an unexpected exception:

Remix error

Thanks for your help! ❤️

About this issue

  • Original URL
  • State: open
  • Created 2 years ago
  • Reactions: 18
  • Comments: 20 (5 by maintainers)

Most upvoted comments

@MisteryPoints Try cloning the request object, and read data separately from that cloned object. Even I faced the same issue, and have solved it by following this approach -

export async function action(props) {
    const {request} = props 
    const clonedData = request.clone()
    const formDatas = await clonedData.formData()
    const  data =  {
      title: formDatas.get('title'),
      slug: formDatas.get('slug')
    } 
    await createCategory(data)  
    const uploadHandler = unstable_createFileUploadHandler({
      maxPartSize: 10_000_000,
      directory: path.join(__dirname, '..', `public/uploads`),
      file: ({ filename }) => filename,
    })
    const formData = await unstable_parseMultipartFormData(
      request,
      uploadHandler
    ) 
    const image = formData.get('image') 
    
    if (image) {
      console.log(`File uploaded to server/public/uploads/${image.name}`)
    } else {
      console.log("No file uploaded");
    } 
    return redirect('/')
}

I see this was assigned and then unassigned - any progress on this?

Also facing this issue, the following is my investigation

I think this issue can’t be solve by clone the request, it is when request aborted will throw an error which even can’t be catch from user side, so the server crash by this unhandled error.

  1. remix-run/node overwrite the default fetch under the hood, https://github.com/remix-run/remix/blob/27e7ac2959146e8c158382da2a65f9afe9d1a67f/packages/remix-node/globals.ts#L55
  2. the implementation in remix-run/web-std-io could be found at https://github.com/remix-run/web-std-io/blob/d2a003fe92096aaf97ab2a618b74875ccaadc280/packages/fetch/src/fetch.js#L39
  3. the issue is https://github.com/remix-run/web-std-io/blob/d2a003fe92096aaf97ab2a618b74875ccaadc280/packages/fetch/src/fetch.js#L75
  4. this error is throw by underline polyfill readable stream, seems like it will throw error if the response body has been locked (because it will be consume by http request). https://github.com/MattiasBuelens/web-streams-polyfill/blob/d354a7457ca8a24030dbd0a135ee40baed7c774d/src/lib/readable-stream.ts#L149
  5. seems like the test case didn’t do a good job, the controller abort the request before it actually fired, the request.body is not be consume by reader yet. https://github.com/remix-run/web-std-io/blob/d2a003fe92096aaf97ab2a618b74875ccaadc280/packages/fetch/test/main.js#L1129

the test case below try to defer the controller abort, after the request.body be consume.

diff --git a/packages/fetch/src/fetch.js b/packages/fetch/src/fetch.js
index fcbc379..6a46f77 100644
--- a/packages/fetch/src/fetch.js
+++ b/packages/fetch/src/fetch.js
@@ -72,6 +72,8 @@ async function fetch(url, options_ = {}) {
                        const error = new AbortError('The operation was aborted.');
                        reject(error);
                        if (request.body) {
+                               console.log('request.body', request.body)
+                               console.log('request.body.locked', request.body.locked)
                                request.body.cancel(error);
                        }

diff --git a/packages/fetch/test/main.js b/packages/fetch/test/main.js
index cc02728..0b7d95f 100644
--- a/packages/fetch/test/main.js
+++ b/packages/fetch/test/main.js
@@ -1126,7 +1126,9 @@ describe('node-fetch', () => {
                                                .and.have.property('name', 'AbortError')
                                ]);

-                               controller.abort();
+                               setTimeout(() => {
+                                       controller.abort();
+                               }, 10)

                                return result;
                        });

I didn’t solve this issue, need other people input.

Also, attach a repository for reproduce this issue

https://github.com/kayac-chang/remix-abort-test/tree/main

https://gitpod.io/start/#kayacchang-remixabortte-0ohsnxppt54

This still seems to be an active issue, I just ran into it too.

i found this issue at fetch writeToStream(request_, request); https://github.com/remix-run/web-std-io/blob/main/packages/fetch/src/fetch.js#L317C3-L317C16 bodey.js StreamIterableIterator.getReader not rleaseLock or cancel who can fix it ??

It’s working great from the loader of the routes with RemixJS 1.7.0, but I’m getting this error with a POST HTTP request from a simple action:

export const action: ActionFunction = async ({ request }) => {
  const formData = await request.formData();
  const email = formData.get('email')?.toString();
  try {
    await httpRequest(`${apiURL}/auth`, {
      method: 'POST',
      body: JSON.stringify({
        email,
      }),
      parseJSON: false,
      timeout: 1000,
    });

    return redirect('/login');
  } catch (error) {
    return {
      error: (error as Error)?.message,
    };
  }
};

Output:

/node_modules/web-streams-polyfill/src/lib/readable-stream.ts:149
      return promiseRejectedWith(new TypeError('Cannot cancel a stream that already has a reader'));
                                 ^
TypeError: Cannot cancel a stream that already has a reader
    at ReadableStream.cancel (/node_modules/web-streams-polyfill/src/lib/readable-stream.ts:149:34)
    at abort (/node_modules/@remix-run/web-fetch/src/fetch.js:75:18)
    at AbortSignal.abortAndFinalize (/node_modules/@remix-run/web-fetch/src/fetch.js:91:4)
    at AbortSignal.[nodejs.internal.kHybridDispatch] (node:internal/event_target:694:20)
    at AbortSignal.dispatchEvent (node:internal/event_target:636:26)
    at abortSignal (node:internal/abort_controller:292:10)
    at AbortController.abort (node:internal/abort_controller:323:5)
    at Timeout._onTimeout (/apps/webapp/app/utils/http.ts:21:42)
    at listOnTimeout (node:internal/timers:559:17)
    at processTimers (node:internal/timers:502:7)

App Error

Please let me know and thanks for your help!

I have similar issue, but not the same. “TypeError: This stream has already been locked for exclusive reading by another reader”

Im trying to request text from Form Data and Files too. But Form has 2 different methods, but not possible to read the request with both of them. Sorry if my code isnt efficent enough but im trying.

export async function action(props) {
    const {request} = props 
    const formDatas = request.formData()
    const  data =  {
      title: formDatas.get('title'),
      slug: formDatas.get('slug')
    } 
    await createCategory(data)  
    const uploadHandler = unstable_createFileUploadHandler({
      maxPartSize: 10_000_000,
      directory: path.join(__dirname, '..', `public/uploads`),
      file: ({ filename }) => filename,
    })
    const formData = await unstable_parseMultipartFormData(
      request,
      uploadHandler
    ) 
    const image = formData.get('image') 
    
    if (image) {
      console.log(`File uploaded to server/public/uploads/${image.name}`)
    } else {
      console.log("No file uploaded");
    } 
    return redirect('/')
}

Also facing this issue, the following is my investigation

I think this issue can’t be solve by clone the request, it is when request aborted will throw an error which even can’t be catch from user side, so the server crash by this unhandled error.

  1. remix-run/node overwrite the default fetch under the hood, https://github.com/remix-run/remix/blob/27e7ac2959146e8c158382da2a65f9afe9d1a67f/packages/remix-node/globals.ts#L55

  2. the implementation in remix-run/web-std-io could be found at
    https://github.com/remix-run/web-std-io/blob/d2a003fe92096aaf97ab2a618b74875ccaadc280/packages/fetch/src/fetch.js#L39

  3. the issue is https://github.com/remix-run/web-std-io/blob/d2a003fe92096aaf97ab2a618b74875ccaadc280/packages/fetch/src/fetch.js#L75

  4. this error is throw by underline polyfill readable stream, seems like it will throw error if the response body has been locked (because it will be consume by http request).
    https://github.com/MattiasBuelens/web-streams-polyfill/blob/d354a7457ca8a24030dbd0a135ee40baed7c774d/src/lib/readable-stream.ts#L149

  5. seems like the test case didn’t do a good job, the controller abort the request before it actually fired, the request.body is not be consume by reader yet. https://github.com/remix-run/web-std-io/blob/d2a003fe92096aaf97ab2a618b74875ccaadc280/packages/fetch/test/main.js#L1129

the test case below try to defer the controller abort, after the request.body be consume.

diff --git a/packages/fetch/src/fetch.js b/packages/fetch/src/fetch.js
index fcbc379..6a46f77 100644
--- a/packages/fetch/src/fetch.js
+++ b/packages/fetch/src/fetch.js
@@ -72,6 +72,8 @@ async function fetch(url, options_ = {}) {
                        const error = new AbortError('The operation was aborted.');
                        reject(error);
                        if (request.body) {
+                               console.log('request.body', request.body)
+                               console.log('request.body.locked', request.body.locked)
                                request.body.cancel(error);
                        }

diff --git a/packages/fetch/test/main.js b/packages/fetch/test/main.js
index cc02728..0b7d95f 100644
--- a/packages/fetch/test/main.js
+++ b/packages/fetch/test/main.js
@@ -1126,7 +1126,9 @@ describe('node-fetch', () => {
                                                .and.have.property('name', 'AbortError')
                                ]);

-                               controller.abort();
+                               setTimeout(() => {
+                                       controller.abort();
+                               }, 10)

                                return result;
                        });

I didn’t solve this issue, need other people input.

I see this error when canceling a fetch request with AbortController. When I use remix’s fetch library with graphql-request instead of the default node-fetch that it uses, I run into this sometimes when calling controller.abort()

For now, I decided not to use Remix’s custom fetch library for that purpose.

The Remix team has been working on that; they want to remove the polyfill on node> = 18. but the readable stream is still experimental so it may take some time. https://github.com/remix-run/web-std-io/pull/42

Thank the team for the fantastic work here! 🙏🙏🙏

when the fetch request times out, abort will be triggered and an error will be throw

Also facing this issue, the following is my investigation I think this issue can’t be solve by clone the request, it is when request aborted will throw an error which even can’t be catch from user side, so the server crash by this unhandled error.

  1. remix-run/node overwrite the default fetch under the hood, https://github.com/remix-run/remix/blob/27e7ac2959146e8c158382da2a65f9afe9d1a67f/packages/remix-node/globals.ts#L55
  2. the implementation in remix-run/web-std-io could be found at https://github.com/remix-run/web-std-io/blob/d2a003fe92096aaf97ab2a618b74875ccaadc280/packages/fetch/src/fetch.js#L39
  3. the issue is https://github.com/remix-run/web-std-io/blob/d2a003fe92096aaf97ab2a618b74875ccaadc280/packages/fetch/src/fetch.js#L75
  4. this error is throw by underline polyfill readable stream, seems like it will throw error if the response body has been locked (because it will be consume by http request). https://github.com/MattiasBuelens/web-streams-polyfill/blob/d354a7457ca8a24030dbd0a135ee40baed7c774d/src/lib/readable-stream.ts#L149
  5. seems like the test case didn’t do a good job, the controller abort the request before it actually fired, the request.body is not be consume by reader yet. https://github.com/remix-run/web-std-io/blob/d2a003fe92096aaf97ab2a618b74875ccaadc280/packages/fetch/test/main.js#L1129

the test case below try to defer the controller abort, after the request.body be consume.

diff --git a/packages/fetch/src/fetch.js b/packages/fetch/src/fetch.js
index fcbc379..6a46f77 100644
--- a/packages/fetch/src/fetch.js
+++ b/packages/fetch/src/fetch.js
@@ -72,6 +72,8 @@ async function fetch(url, options_ = {}) {
                        const error = new AbortError('The operation was aborted.');
                        reject(error);
                        if (request.body) {
+                               console.log('request.body', request.body)
+                               console.log('request.body.locked', request.body.locked)
                                request.body.cancel(error);
                        }

diff --git a/packages/fetch/test/main.js b/packages/fetch/test/main.js
index cc02728..0b7d95f 100644
--- a/packages/fetch/test/main.js
+++ b/packages/fetch/test/main.js
@@ -1126,7 +1126,9 @@ describe('node-fetch', () => {
                                                .and.have.property('name', 'AbortError')
                                ]);

-                               controller.abort();
+                               setTimeout(() => {
+                                       controller.abort();
+                               }, 10)

                                return result;
                        });

I didn’t solve this issue, need other people input.

Also, attach a repository for reproduce this issue https://github.com/kayac-chang/remix-abort-test/tree/main https://gitpod.io/start/#kayacchang-remixabortte-0ohsnxppt54

I’m pretty sure Remix accepts PRs with a failing test case as a bug report, so if you’re able to reproduce it in a test case and open a PR, that might bring this issue some attention.

Thank you for the suggestion, I will do that as soon as possible.

I also ran into this as well. For now, as a workaround (to @aniravi24’s point of avoiding the web-fetch usage), I did the following:

  • added node-fetch 2 to packages.json (since node-fetch 3 is ESM only)
"node-fetch": "^2",
  • Then add the following to a fetchOverlay.server.ts file
const nodeFetch = require("node-fetch");
let fetchOverlay = false;
export function setupFetch() {
  if (!fetchOverlay) {
    globalThis.fetch = nodeFetch as any;
    fetchOverlay = true;
  }
}
  • Call setupFetch() somewhere common (or in root)