[Bug]: File extension is missing on Windows

[Sharcoux]

Preflight Checklist

• I have read the Contributing Guidelines for this project.
• I agree to follow the Code of Conduct that this project adheres to.
• I have searched the issue tracker for a bug report that matches the one I want to file, without success.

Electron Version

18.1.0

What operating system are you using?

Windows

Operating System Version

Windows 10 - 10.0.19042

What arch are you using?

x64

Last Known Working Electron version

No response

Expected Behavior

When saving a file, the file type should be correctly defined and the filename should include the extension on the operating system so that the correct program is launch when double-clicking it

Actual Behavior

The extension is missing.

Here is the code we are using:

  const a = document.createElement('a')
  a.type = getMimeType(name)
  a.href = `data:${a.type || 'text/plain'};base64,${base64}`
  a.download = name
  a.click()

I'll try to add a fiddle later

Testcase Gist URL

https://gist.github.com/c07b1efe128ba059d0fad7ebeb7a94cb

Additional Information

This is reproducible only on Windows

[Sharcoux]

This might be a duplicate that, maybe, should be reopened.

[deermichel]

Hi @Sharcoux, thanks for reporting this and helping to make Electron better!

I was able to repro this on Electron 19, though an Electron Fiddle gist would be much appreciated, please follow up with one. As a workaround, including the file extension in the filename should work (or consider using the native save dialog as suggested in the issue you linked).

[Sharcoux]

Thanks for your investment. The issue is that, as the type is not specified, if the user want to rename the file, they will very likely lose the extension... So the workaround is not enough for our users, as they are not friendly with computer science ^^"

Here is the fiddle