Sourcemaps are triggering the download of the mapped files when developer tools are open

By design Issue #11014505


Ricardo B.
Feb 21, 2017
This issue is public.
Found in
  • Microsoft Edge
Reported by 1 person

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Steps to reproduce

On Edge, when the developer tools are open, all the source files are downloaded.


1 - Open Edge
2 - Open Developer Tools
3 - Go to

You should see 3 downloads instead of 2 (the .coffe script is also being downloaded). You can also confirm this with fiddler.


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    Comments and activity

    • Microsoft Edge Team

      Changed Assigned To to “Jacob R.”

      Changed Status to “Confirmed”

      Changed Assigned To to “Leo L.”

      Changed Assigned To from “Leo L.” to “Anubha M.”

      Changed Assigned To from “Anubha M.” to “Leo L.”

      Changed Assigned To from “Leo L.” to “Anubha M.”

      Changed Status from “Confirmed” to “By design”

    • Hello,

      Thank you for providing this information about the issue. F12 by default has the ‘Load sources mapped to this generated file’ icon toggled. If it is toggled, then the user will see in the js folder and when they open the file, actually see that the toggle is highlighted. Disabling the toggle and refreshing the page correctly produces main.js in the js folder; no longer appears.
      The state of this icon is persistent in F12. If the user didn’t want the source maps to download, they would just turn off this toggle. Currently, we do not plan to release a fix for this problem. Please reopen this case if you can provide new information for us to consider.

      Best Wishes,
      The MS Edge Team

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