x/tools/gopls: List all function signatures in function completion list using `CompletionItemLabelDetails`

[myonlylonely]

For now, VSCode only will show the signature of the selected function. To see other function defines, we have to move cursor to make the selection. Is it possible to show all the function signatures like in GoLand?

This is now in VSCode:

And this is now in GoLand:

It will be a huge help if gopls could also support this kind of completion hints like GoLand.
There might be a performance hit, but we could make it a optional.

[gabyhelp]

Related Issues

• x/tools/gopls: move function signature into detail for completion #32414 (closed)
• x/tools/gopls: don't trigger signature help from completion #37966 (closed)

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[h9jiang]

LSP 3.17 introduces the CompletionItemLabelDetails inside of CompletionItem interface, we can use this instead. I don't think gopls is currently using this field at all. Maybe worth doing the migration from detail to the label detail.

References:
originial discussion: microsoft/vscode#39441
spec: lsp
spec in x/tools: code

Today, gopls report function signature for completion items using detail, but the detail can only be rendered in vscode if being selected. However, the vscode render CompletionItemLabelDetails without being selected. I think it's a good place to hold the signature information.

        {
            "label": "Print",
            "kind": 3,
            "detail": "func(a ...any) (n int, err error)",
            "documentation": {}
        }

[myonlylonely]

It will be great if we could support that! 👍