Emulated devices get Edg appended to their user agent when dev tools are opened

[XLeapZan]

I'm using Edge 124.0.2478.51, any custom user agent added to the device simulator gets 'Edg/124.0.0.0' appended to its user agents when the dev tools are reopened.

Steps to reproduce:

• Open DevTools
• Enable device emulation
• Add a custom device and specify a user agent. Don't specify Edg anywhere in the string)
• Close DevTools
• Reopen DevTools
• Verify custom device

Current behavior:

• the user agent has been changed and Edg/124.0.0.0 has been appended
  (this happens to all custom user agents that don't already have Edg in their string)

Expected:

• The user agent of custom devices will remain unchanged.

P.S. This also happens to the built-in device user agents. I suppose you could argue that it should emulate Edge on those devices, but then I would then expect, for example, for an 'iPad Mini' to say
'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/16.0 Safari/605.1.15 EdgiOS/124.0.0.0'
but it still appends 'Edg/124.0.0.0'.

AB#50298790

[captainbrosset]

Thanks for the report. I've tested this just now and can reproduce the issue locally. I will put this on our dev team's backlog.

[yilihjy]

In Microsoft Edge Version 133.0.3065.92 (Official build) (64-bit), I'm still encountering this issue where my custom User-Agent string is being automatically appended with "Edg/133.0.0.0".

[mmis1000]

Still hit this in 140.0.3485.66 (正式組建) (arm64) , all user agent are appended with "Edg/140.0.0.0". It's quite annoying when you are actually dealing with page that does require to agent sniffing. The appended string cause the detection to fail unexpectedly.

[vidorteg]

Hi everyone,
Devtools dev here. This should be fixed in version 151.0.4118.0:

• If you specify a custom user agent, it should not be appended with Edg/versions anymore.
• User agent should also be fixed for mobile devices to correctly reflect ios and android agents.

As a side note Edg/<version> is not a type is a way to differentiate between Chromium-based Edge from EdgeHTML based browser (previous version):
https://learn.microsoft.com/en-us/microsoft-edge/web-platform/user-agent-guidance#user-agent-strings