Add Pylance setting and prompt for install if Pylance extension is missing

[MikhailArkhipov]

For #13122

• Add Pylance setting to python.languageServer

• Check if Pylance is installed and prompt for install if it is missing

• Related tests

• Add few strings to localization

• Pull request represents a single change (i.e. not fixing disparate/unrelated things in a single PR).

• Title summarizes what is changing.

• Has a news entry file (remember to thank yourself!).

• Appropriate comments and documentation strings in the code.

• Has sufficient logging.

- [ ] Has telemetry for enhancements.

• Unit tests & system/integration tests are added/updated.

- [ ] Test plan is updated as appropriate.
- [ ] package-lock.json has been regenerated by running npm install (if dependencies have changed).
- [ ] The wiki is updated with any design decisions/details.

[codecov-commenter]

Codecov Report

Merging #13123 into master will decrease coverage by 0.16%.
The diff coverage is 92.96%.

@@            Coverage Diff             @@
##           master   #13123      +/-   ##
==========================================
- Coverage   59.79%   59.62%   -0.17%     
==========================================
  Files         671      670       -1     
  Lines       36681    36835     +154     
  Branches     5158     5189      +31     
==========================================
+ Hits        21933    21963      +30     
- Misses      13655    13777     +122     
- Partials     1093     1095       +2     

Impacted Files	Coverage Δ
src/client/activation/common/activatorBase.ts	13.22% <ø> (-9.00%)	⬇️
...t/activation/common/languageServerFolderService.ts	98.36% <ø> (ø)
src/client/activation/node/languageServerProxy.ts	26.58% <0.00%> (ø)
src/client/activation/node/manager.ts	26.78% <0.00%> (ø)
src/client/common/featureDeprecationManager.ts	40.90% <ø> (ø)
...active-common/intellisense/intellisenseProvider.ts	37.73% <ø> (+0.11%)	⬆️
src/client/providers/jediProxy.ts	23.59% <0.00%> (ø)
src/client/telemetry/constants.ts	100.00% <ø> (ø)
src/client/telemetry/index.ts	82.35% <ø> (ø)
src/client/activation/activationService.ts	89.72% <91.66%> (+5.57%)	⬆️
... and 90 more

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[jakebailey]

One other thing that would be good to do:

Right now, for people without Pylance installed, it's going to be two reloads because the process is like:

1. Change in the settings to Pylance. Extension prompts "LS changed, please reload".
2. New Pylance code runs, and Pylance extension isn't installed. Extension prompts "go here to get Pylance".

Can the first step be modified to say "if changing to Pylance and Pylance not installed, load pylance banner instead"? That way you only have the one reload to actually finish the whole process.

[MikhailArkhipov]

Basically activator and change settings tracker should be calling the same code that would check if Pylance is installed. So the code needs to move from activator into some shared class.

[jakebailey]

Some of it, anyway. Three lines to do if (this.extensions.getExtension(PYLANCE_EXTENSION_ID) { ... } is probably not worth the abstraction, but the rest of the banner yeah.

[jakebailey]

Behavior looks good to me.

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!

0 Bugs
0 Vulnerabilities (and 0 Security Hotspots to review)
1 Code Smell

No Coverage information
0.9% Duplication