tsserver should implement the Language Server Protocol

[mickaelistria]

As the language server protocol ( https://github.com/Microsoft/language-server-protocol ) is getting more and more popularity and clients ( https://github.com/Microsoft/language-server-protocol/wiki/Protocol-Implementations ), it would be very useful to have the tsserver implement this protocol.

[StevenDoesStuffs]

Been 2 monthts, any updates?

[felixfbecker]

We did some work at Sourcegraph in wrapping the TS language service as a language server, but hit some limitations with the current API. Specifically, the LanguageServiceHost interface you can provide to the server requires the methods that return file contents to return synchronously. In a language server however this is most likely done asynchronously because retrieving the file content involves IO with the file system or over the protocol stream.

I would be very interested in help or improvements in the TS server to solve this use case.

[masaeedu]

@felixfbecker Would it be possible to overcome the limitations if you interfaced with an instance of tsserver instead?

[felixfbecker]

@masaeedu I don't understand the question - the TS language server is using the LanguageService from TypeScript?

[masaeedu]

@felixfbecker Sorry, I'll try to clarify what I mean. Instead of implementing LanguageServiceHost, you could let tsserver host the language service, and you wouldn't need to care about how it satisfies that interface. Your language server process would rely on passing messages to/from tsserver, which is inherently async.

[felixfbecker]

@masaeedu wouldn't the tsserver try to read from the file system directly?

[masaeedu]

@felixfbecker Yeah, it would read the files directly. I don't think that would affect your language server process in any way though. If/when they make performance improvements to tsserver you don't need to make any changes.

[felixfbecker]

@masaeedu That is a dealbreaker unfortunately, because the files are not available locally in the container.