Canceling on Fetch reader fails with DOMException InvalidStateError

Fixed Issue #11862013


Kagami R.
May 2, 2017
This issue is public.
Found in
  • Microsoft Edge
Standard affected
Streams Standard

Found in build #
Reported by 1 person

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Steps to reproduce

const reader = stream.getReader();
const aborter = () => {
    //return reader.cancel(); // does not work on Edge 15
    return stream.cancel();
let aborterId = setTimeout(aborter, 90000);

We recently tried transition from MSStream to Fetch stream on our UWP JavaScript app, and experienced a bug on reader.cancel()

Per the spec the reader.cancel() should work as same as reader.releaseLock() + stream.cancel() but the former fails, the latter succeeds. No idea why.

Also, the spec never refers InvalidStateError.


  1. Click the button to cancel stream.
  2. Expected to stop as it does on Chrome but not.


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    Comments and activity

    • Changed Steps to Reproduce

    • Microsoft Edge Team

      Changed Assigned To to “James M.”

    • Hello,

      Thank you for providing this information about the issue. Unfortunately, we are unable to reproduce this problem in Edge with the information at hand. Please update this case with a sample project or webpage which shows the problem.

      Best Wishes,
      The MS Edge Team

    • Changed Steps to Reproduce

    • Hi, I updated the repro step.

    • Microsoft Edge Team

      Changed Assigned To to “Venkat K.”

      Changed Assigned To from “Venkat K.” to “Mohamed K.”

      Changed Status to “Confirmed”

    • Edge now exhibits same behavior as Opera does, probably fixed now :D

    • Microsoft Edge Team

      Changed Status from “Confirmed” to “Fixed”

    • This issue was fixed in the latest Windows insider preview build. Thank you for your feedback!

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