feat: snippet completions for functions

[llllvvuu]

resolves #56

demo.mp4

tsserver does not create snippets for functions in the completions list; only upon completion resolve (presumably this is for performance reasons).

typescript-language-server deals with this by manually constructing the snippet and tweaking the inputTextFormat. We copy that here - as long as includeCompletionsWithSnippetText = true.

I chose to do one thing different fromtypescript-language-server: even though we can't put preview all the snippet params in the cmp menu, I still at least add "(...)" so that it visually distinguishes them as snippets. This is especially since nvim_cmp is unable to detect them as snippets.

Note that VSCode's own completeFunctionCalls feature is very rough around the edges. For example, it doesn't work on arrow functions, which is fundamentally because tsserver labels then as variables and so it doesn't make sense for them to be inputTextFormat = Snippet.

INFO:
refactor/fix: move default configs to config.lua so they can be referenced outside of just text_document/did_open
test: test both the completeFunctionCalls = true case and completeFunctionCalls = false case.

[pmizio]

Very nice! Thank you for contribution! I looked into code and it looks fine, but can you add type annotations for new functions and ad least one test which contain new snippet response for regression purposes?
In the meantime I test it in my setup.

[llllvvuu]

@pmizio Sure, no problem, just added. For the tests, this feature actually turned the existing test cases into snippets, so I instead added back test cases for non-snippets.

[pmizio]

@pmizio Sure, no problem, just added. For the tests, this feature actually turned the existing test cases into snippets, so I instead added back test cases for non-snippets.

I mean more to assert constructed snippet which you add to resolve response here

[llllvvuu]

I mean more to assert constructed snippet which you add to resolve response here

The value is the same as item.insertText: https://github.com/pmizio/typescript-tools.nvim/pull/116/files#diff-bb318b020a15617a49a83e92a30945b0ee02d37c1a9129c2768ade494dd91e03R105-R108

Which is tested here:

https://github.com/pmizio/typescript-tools.nvim/pull/116/files#diff-583bd8b57593fbf434045965a180c48661e07c2abd34cbf8c88da15d14e05ad9R197

I'm actually not sure how to trigger the item.textEdit.newText route specifically. It comes from item.replacementSpan being defined, which doesn't seem to be happening in any case for me.

[pmizio]

I mean more to assert constructed snippet which you add to resolve response here

The value is the same as item.insertText: https://github.com/pmizio/typescript-tools.nvim/pull/116/files#diff-bb318b020a15617a49a83e92a30945b0ee02d37c1a9129c2768ade494dd91e03R105-R108

Which is tested here:

https://github.com/pmizio/typescript-tools.nvim/pull/116/files#diff-583bd8b57593fbf434045965a180c48661e07c2abd34cbf8c88da15d14e05ad9R197

I'm actually not sure how to trigger the item.textEdit.newText route specifically. It comes from item.replacementSpan being defined, which doesn't seem to be happening in any case for me.

Oh, I'm blind sorry :D ok I will work with this for one or two days and merge it if everything will be ok. Once again thanks for contrib!

[pmizio]

@llllvvuu Just noticed one thing - ~ char is added multiple times when I leave completion:

Nagranie.z.ekranu.2023-07-24.o.15.04.03.mov

Edit: I checked it and it look like cmp add ~ additionally after resolve phase of completion. So in resolve you probably need to remove tiling ~ or just check out how cmp do things and send correct response in 1st phase of request.

[llllvvuu]

@pmizio good catch, I didn't realize it was nvim-cmp thing, so I removed the code that adds ~ on our side. Instead I added indicator (...). Unfortunately nvim-cmp logic doesn't allow me to trigger the ~ indicator on their side, but I opened an issue for this: hrsh7th/nvim-cmp#1665

I changed one more thing, which is to turn off the feature by default, similar to VSCode. I updated the README.md to show how to turn it on.

[pmizio]

Ok, so I tested this and it looks fine for me to merge, @llllvvuu do you want to change something before merge or I can do that?

[llllvvuu]

@pmizio All good on my end 👍

[pmizio]

Once again thanks for contrib @llllvvuu!