csharp-ls seems to conflate definition with implementation?

[josteink]

Not sure if this is the fault of csharp-ls or not, but it seems like a good place to start 😄

Consider the following c# code:

interface IDemo
{
    void Foo();
}

class Demo : IDemo
{
    void Foo()
    {
        Console.WriteLine("Bar");
    }
}

When positioning the cursor at IDemo (line 6) and selecting (in Emacs) lsp-find-definition I'm taken to line 1, where the interface is defined. This makes sense.

However when I use lsp-find-implementation at IDemo (line 1), I expect to be given the implementations of that interface (line 6). Instead the behaviour seems to be just like lsp-find-definition, and I remain at line 1.

Are these two functions implemented the same way inside csharp-ls? Or is this a lsp-mode issue? Or have I simply misunderstood something about what the current C# LSP providers are capable of?

[josteink]

Looking at the code that does indeed seem to be the case:

csharp-language-server/src/CSharpLanguageServer/Server.fs

Lines 685 to 686 in 242409a

	|> Map.add "textDocument/definition" (handleTextDocumentDefinitionOrImpl |> requestHandlingWithStateChange)
	|> Map.add "textDocument/implementation" (handleTextDocumentDefinitionOrImpl |> requestHandlingWithStateChange)

[razzmatazz]

Yeah, that was a cheap shot on my part to get something working but I didn’t get that much into semantic differences to realize it’s a bad idea :)

[josteink]

Fair enough. But IMO it's probably better/more correct to not advertise the "find implementation" capability until that is sorted out.

What do you think?

[razzmatazz]

oh definitely