Add checkers for TypeScript

[prashcr]

Specifically, tsc (or maybe tsuquyomi) and tslint

Status

• TSLint
• Tsuquyomi/tsc

[w0rp]

I'm totally in favour of this. I think I'm generally in favour of adding more support for linting everything. I'll probably start using TypeScript personally soon enough.

[prashcr]

Great!

tslint

Style checking
Just needs stdin wrapper, pretty straightforward.
Out of curiosity, what's the rationale behind requiring linters to accept stdin?

tsc

Syntax and type checking
tsc is the official typescript compiler, however it's really slow (takes 2 seconds for a hello world).

TypeScript also comes with a tool called TSServer which uses some caching magic to run the same checks extremely fast, at the cost of a few hundred ms at startup. Aside from checking, it also adds intellisense autocomplete. This is what's used in Sublime/VS Code/WebStorm.

tsuquyomi

This plugin wraps TSServer and makes it really easy to use.
However, this uses vimproc.vim, an async task runner, to populate the quickfix list.

Syntastic's approach to this problem was to add a syntastic checker in the tsuquyomi repo itself and add an option to disable tsuquyomi's use of the quickfix list.

I'm not sure how to approach this.
Do we just use tsuquyomi and accept that people need to install an async task runner when they're already using vim 8? And do we try and integrate changes into their repo so that we can feed its output directly into ALE?
On the other hand, directly wrapping TSServer also seems like too much work that shouldn't belong here.
Maybe we should fork tsuquyomi to use vim8 async?

[w0rp]

I suppose we'd need to rewrite what tsuquyomi does to use the new Vim 8 functionality. It probably used vimproc because the new async functions weren't available at the time.

The linters need to accept stdin input because we need to be able to send the text for files which are open without first saving the files back to disk. The linting is applied by sending the contents of the text buffer directly to a given program. I might write a Bash wrapper script will could be used for sending input to most programs. Then eventually I might add a Batch wrapper script for Windows, which will be... interesting.

[w0rp]

I just remembered that I actually already wrote such a Bash wrapper script. I forgot that I did that.

[prashcr]

I'd like to still keep track of this, because TSLint only handles style checks but not compile/type checks which are the main selling point of TypeScript.

For the latter one needs to still install vimproc,tsuquyomi then use :w to check. (Even though vimproc provides async, it just means that vim doesn't freeze when makeprg is run instead of lint-as-you-type)

[w0rp]

I'll re-open this one then. I wonder if TypeScript has something like switch for checking semantics without producing output. That's what I set up for D with the reference D compiler.

[prashcr]

Ah, that's a great idea. It does have a switch for that. I'll try using that and seeing if perf is acceptable

[prashcr]

Unfortunately disabling output had no effect on linting speed, still too slow.

On the bright side, I noticed that not many files in the Tsuquyomi project use vimproc, and they use it for job control. I'll try forking it and making it work with vim8 jobs intstead .

[w0rp]

Let me know how you get on. Sounds good to me. 👍