Semantic highlights in session based TSServer

[orta]

Fixes #41262 - I've cloned https://github.com/microsoft/vscode/tree/dev/mjbvz/semantic-ts locally and get working results from the tokenized files. I'm pretty sure this should be it @mjbvz!

[typescript-bot]

Thanks for the PR! It looks like you've changed the TSServer protocol in some way. Please ensure that any changes here don't break consumers of the current TSServer API. For some extra review, we'll ping @sheetalkamat, @amcasey, @mjbvz, @minestarks for you. Feel free to loop in other consumers/maintainers if necessary

[orta]

@typescript-bot pack this

[typescript-bot]

Heya @orta, I've started to run the tarball bundle task on this PR at ac1ac4d. You can monitor the build here.

[typescript-bot]

Hey @orta, I've packed this into an installable tgz. You can install it for testing by referencing it in your package.json like so:

{
    "devDependencies": {
        "typescript": "https://typescript.visualstudio.com/cf7ac146-d525-443c-b23c-0d58337efebc/_apis/build/builds/93903/artifacts?artifactName=tgz&fileId=4023455FB96E93ECEC8FD812E1AFFCEBF6E5897774A7ABA3A14D36AA78D23F9E02&fileName=/typescript-4.2.0-insiders.20210121.tgz"
    }
}

and then running npm install.

---

There is also a playground for this build and an npm module you can use via "typescript": "npm:@typescript-deploys/[email protected]".;

[orta]

Thanks Sheetal, it's a small change I'm pretty confident with - so I'm merging