Add ability to turn off insider prompt when using VSCode insiders for UI Tests

[DonJayamanne]

Currently there's no way to turn off the Insiders Prompts when using VS Code Insiders.
This needs to be turned off for the UI Tests (the prompt blocks the extension and adds unnecessary messages, and complicates testing as well). We can work around this, but its just not worth the effort in the UI Tests.

Proposed solution: Add a setting (that won't be exposed to users) to turn off insiders feature.

As this won't impact users I'm not adding the needs decision flag, its something that will be used only on CI for UI Tests.

@brettcannon @karrtikr /cc

Please advice if you disagree with the proposed change.

[karrtikr]

Just one thing, why is python.insidersChannel explicitly set to "off" in the user settings in the first place? Is it possible to initialize UI tests with total clean environments?

[DonJayamanne]

The requirement is simple, I don't want any insiders prompts , at all.
In VS Code insiders, even if python.insidersChannel=off the prompt is displayed.

Just one thing, why is python.insidersChannel explicitly set to "off" in the user settings in the first place? Is it possible to initialize UI tests with total clean environments?

This used to work before you added the change to check if it is set to off explicitly and displayed a prompt to re-install.
So, that setting used to work, but not anymore.

Again, the requirement is no prompts for UI tests.

[karrtikr]

I realize that it used to work, I was just wondering what put "python.insidersChannel": "off" in the settings.json in the UI tests.

The solution you proposed seems just fine

Proposed solution: Add a setting (that won't be exposed to users) to turn off insiders feature.

Can we have a process environment variable instead, or a file?