Add API for registering an external file watcher implementation

[rchl]

Allows to create external package that implements the file watcher API.

See example implementation at sublimelsp/LSP-file-watcher-chokidar#1

[rwols]

Would be better if this were binary_file_patterns and/or index_exclude_patterns. But the glob syntax/features of ST is unfortunately incomplete compared to VSCode.

[rwols]

Wouldn't you need **/.svn/** here as well?

[rchl]

Someone is using SVN still? :)

I can add of course but was planning to look into fetching ignores from ST and converting to glob but that might turn out to be some work.

[rwols]

Someone is using SVN still? :)

Unfortunately, yes, these companies exist ;) But I think it's okay to forget about it and focus on fetching the ignore list from ST instead.

[rchl]

On the high-level this seems fine?

I'm open to nitpicking too. :)

[rwols]

I’m quite busy with IRL responsibilities, will review maybe Thursday or Friday. But one thing I do miss is some sort of integration test with the test/server.py file.

[predragnikolic]

On the high-level this seems fine?

Yes, the api looks nice (not to many methods exposed and the one that are exposed are reasonably easy to understand) 🙂

[rchl]

I'll say it's ready for review although would be good to also handle ST's exclude patterns. Maybe it wouldn't be too hard to convert those to globs.

[rchl]

Note:

• changes in sessions.py are much more readable with "hide whitespace changes" enabled. Had to extract each capability group into a variable to avoid type issue.
• removed the on_register_capability_async and on_unregister_capability_async APIs which to my knowledge were only used by me in my previous file watcher implementation.
• The watchers are only registered if there are workspace folders. I think something else wouldn't make sense.
• I think I'm not handling workspace folder changes. Should reset/recreate the watchers then.

[rwols]

Looks like you've put a lot of work into this.

[rwols]

Let's go ahead with this for now and work out the kinks.