Support frequent out of band updates to the language server

[DonJayamanne]

I.e. as support to download language server more frequently.
E.g. once a week.
@qubitron @MikhailArkhipov
Would downloading once a week work? It do we download Everytime we come across a new release.
Please note, new versions will only be downloaded when the extension is loaded.

Option 1 (does not block use)

• When extension loads look kor a new version

• If a new version exists, download and extract (in background)

• Once completed prompt user to restart vscode to use the new version

  • Options in the message include:
  • [Reload] Will reload vscode
  • [Do not show again] Will not show message again, but when user loads vscode next time, new language server is automatically available.

• Pros, user can continue using extension with older language server, intellisense, navigation, etc will work. I.e. faster loading of extension.

Option 2:

• When extension loads look kor a new version
• If a new version exists, download and extract and continue loading extension
• Pros: current experience
• Cons: Everytime the language server updates, user has to wait for it to download and complete. I.e. shower downloads means, use is unable to get benefits of intellisense, code navigation, etc, cuz language server hasn't started yet.

[d3r3kk]

How will you know there is a new version?

Right now the extension simply downloads from a static URL that has no version information in it.

[DonJayamanne]

Right now the extension simply downloads from a static URL that has no version information in it.

I am yet to discuss this with @MikhailArkhipov
However that's a minor issue (determining the URL).

[qubitron]

As long as Option 1 is reliable and not too difficult to implement then I'm for that, but option 2 is good enough if needed.

[DonJayamanne]

@qubitron @MikhailArkhipov @brettcannon
I've gone with option 2.
Do we need the ability to turn this feature off?
Do we need any prompts before downloading a new version?

@Microsoft/pvsc-team /cc

[MikhailArkhipov]

It would be good to provide ability to turn off updates. Some people may not like us pinging Microsoft servers. AFAIK C# (OmniSharp) does not provide the prompt, it just downloads new bits.

[DonJayamanne]

What should this setting be named:
python.autoUpdateLanguageServer = true

[qubitron]

Live share automatically downloads new versions, so no prompt needed, option to turn it off is a good idea, the proposed setting looks fine to me.

[brettcannon]

I agree with Mikhail that we need a way to turn this off for those that don't want to send anything to Microsoft, no matter how innocuous a version check is.