Extend completion to support language servers which requires an additional "completion item resolve" request

[Gabrielbdd]

There are some language servers that does not include a "textEdit" nor a "additionalTextEdits" on the response of the "textDocument/completion" request, and because of that, some features like auto importing an unqualified type does not work.

An example of that is the TypeScript language server.

Reading the LSP documentation, the way of doing that is issuing a "completion item resolve" request with the "completion item" selected by the user.

If that helps, the TypeScript language server replies the "documentText/completion" with (simplified, extracted from the logs):

{
    "jsonrpc": "2.0",
    "id": 4,
    "isIncomplete": false,
    "result": {
        "items": [
            {
                "label": "Z_BLOCK",
                "kind": 21,
                "sortText": "�24",
                "commitCharacters": [
                    ".",
                    ",",
                    "("
                ],
                "data": {
                    "file": "/home/example/index.ts",
                    "line": 4,
                    "offset": 3,
                    "entryNames": [
                        {
                            "name": "Z_BLOCK",
                            "source": "zlib",
                            "data": {
                                "exportName": "Z_BLOCK",
                                "moduleSpecifier": "zlib",
                                "ambientModuleName": "zlib"
                            }
                        }
                    ]
                },
                "detail": "zlib",
                "tags": [
                    1
                ]
            }
        ]
    }
}

[Gabrielbdd]

I'm pretty new to many things here (Helix, Rust, LSP 😄) but I'm willing (and eager) to help with that.

I looked at how the current implementation works, and right here it applies the "additional edits" on the document.

I'm not sure if that's fine to make the completionItem/resolve request to the language server there, as this file appears to be concerned only with UI logic.

[matoous]

I think this would actually happen in the code_action command around here ~https://github.com/helix-editor/helix/blob/master/helix-term/src/commands.rs#L3277. You would send the codeAction along with the data field to the server codeAction/resolve route to resolve the actions¹ and then apply them as it is done now.

But rather wait for someone experienced.

Also, this overlaps with: #183

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Footnotes

1. https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_codeAction ↩

[Gabrielbdd]

Hi @matoous , I'm not sure if I understood your idea. I agree that the "codeAction/resolve" could be done right where you pointed out. But to solve the problem that I mentioned, the right request to do is the "completionItem/resolve", as said in the docs. And it looks like its not possible to do that at code_action. (But sure, this one also need to be done, I'm sure there are languages that depends on it).

About the solution, "archseer" gave me some direction on the Matrix community about how to do that using "block_on", I will try it and see if that works.

[matoous]

🙈 yes, I just mis-read. You are absolutely right.