Getting "failed get highlight parameter 0 0"

[henrique-ezcater]

Hello!

I am trying get highlight of the parameters in the pop-up, but as soon as I type ( to provide the parameters I get the error failed get highlight parameter 0 0.
This is using pyright and the following python code can be used to reproduce it:

import os

def bla(a: int, b: int, c: int, d: int):
    print(f"a #{a}, b #{b}, c #{c}, d #{d}")

def x(a):
    print("hey! %s" % a)
    bla(

Here is a screenshot:

Here is the debug output:

שׁ  |1: insert enter
שׁ  |1: insert enter
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שׁ  |1: timer start
שׁ  |1: timer start
שׁ  |1: timer start
שׁ  |1: timer start
שׁ  |1: signature triggered
שׁ  |1: sig result |2: {
  activeParameter = 4,
  activeSignature = 0,
  signatures = { {
      activeParameter = 0,
      label = "(a: int, b: int, c: int, d: int) -> None",
      parameters = { {
          label = { 1, 7 }
        }, {
          label = { 9, 15 }
        }, {
          label = { 17, 23 }
        }, {
          label = { 25, 31 }
        } }
    } }
}
 |3: {
  border = "single",
  check_client_handlers = true,
  check_pumvisible = true,
  line_to_cursor = "    bla(",
  trigger_from_lsp_sig = true,
  triggered_chars = { "(", ",", ")" }
}

שׁ  |1: no next param
שׁ  |1: md lines |2: { "```python", "(a: int, b: int, c: int, d: int) -> None", "```" }

שׁ  |1: label: |2: (a: int, b: int, c: int, d: int) -> None |3: 0 |4: 1 |5: 4 |6: {
  activeParameter = 0,
  label = "(a: int, b: int, c: int, d: int) -> None",
  parameters = { {
      label = { 1, 7 }
    }, {
      label = { 9, 15 }
    }, {
      label = { 17, 23 }
    }, {
      label = { 25, 31 }
    } }
}

שׁ  |1: win config |2: {
  border = { "╭", "─", "╮", "│", "╯", "─", "╰", "│" },
  check_client_handlers = true,
  check_pumvisible = true,
  close_events = { "BufHidden", "InsertLeavePre" },
  focus_id = "textDocument/signatureHelplsp_signature795",
  line_to_cursor = "    bla(",
  max_height = 12,
  max_width = 120,
  offset_x = -1,
  stylize_markdown = true,
  trigger_from_lsp_sig = true,
  triggered_chars = { "(", ",", ")" },
  zindex = 200
}

שׁ  |1: extmark |2: 0 |3: 0
שׁ  |1: timer start
שׁ  |1: timer start
שׁ  |1: timer start
שׁ  |1: timer start
שׁ  |1: timer start
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From a quick glance at the code, I couldn't figure out the issue. I got here:

lsp_signature.nvim/lua/lsp_signature_helper.lua

Line 114 in 78af139

local nextParameter = signature.parameters[activeParameter + 1]

Can't really tell why that is returning nil? Or perhaps I am following the code incorrectly. My lua skillz aren't that great.

Any ideas?

Thanks!

[tiagovla]

I have the same issue.

[ray-x]

What LSP you are using?

[tiagovla]

In my case pyright with built in neovim LSP.

[henrique-ezcater]

Same here, using pyright.
I also tested in ruby files with solargraph and have the same issue.

[ray-x]

I think this issue is caused by pyright.

The log you posted:

{
  activeParameter = 4,
  activeSignature = 0,
  signatures = { {
      activeParameter = 0,
      label = "(a: int, b: int, c: int, d: int) -> None",
      parameters = { {
          label = { 1, 7 }
        }, {
          label = { 9, 15 }
        }, {
          label = { 17, 23 }
        }, {
          label = { 25, 31 }
        } }
    } }
}

Check this:

  activeParameter = 4,
  activeSignature = 0,

activeSignature=0, this means it is Zero-based numbering. But activeParameter=4. This is incorrect. I think what pyright means is activeParameter=3

[henrique-ezcater]

Isn't the activeParameter outside of the signatures the count of parameters? I think that the correct would be for the code to be using the internal activeParameter for indexing then, no?

[henrique-ezcater]

I am thinking that perhaps this here needs to be changed:

lsp_signature.nvim/lua/lsp_signature_helper.lua

Lines 95 to 96 in 78af139

	local activeParameter = result.activeParameter or signature.active_parameter
	or signature.activeParameter

The code there perhaps should read:

  local activeParameter = signature.activeParameter + 1

[ray-x]

Different LSP sending activeParameter back in slight different way and that is why

local activeParameter = result.activeParameter or signature.active_parameter 
                             or signature.activeParameter

But activeParameter=4 is incorrect. All LSP activeParameter is 0 based.

[henrique-ezcater]

I had success replacing that line with:

  local activeParameter = signature.activeParameter or signature.active_parameter or result.activeParameter

It works now with pyright.

With solargraph the issue seems to be on the solargraph side as the response from solargraph does not contain the signatures object. I will open an issue with them.

[henrique-ezcater]

I just checked the spec for signatureHelp, here is that it says:

	/**
	 * The index of the active parameter.
	 *
	 * If provided, this is used in place of `SignatureHelp.activeParameter`.
	 *
	 * @since 3.16.0
	 */
	activeParameter?: uinteger;

So the code should really read the way I pasted in my previous reply:

  local activeParameter = signature.activeParameter or signature.active_parameter or result.activeParameter

The activeParameter inside the signature object has precedence over the one outside of it in the result object. Does that make sense?

Here is the link to the documentation: https://microsoft.github.io/language-server-protocol/specifications/specification-3-17/#signatureHelp

[ray-x]

I do not know why the designer decided to send an out of range index to indicate it to be 0 in 3.17 . What a nice pitfall!

I pushed my changes.

[henrique-ezcater]

I checked the changes there, and I think you should still change the order for setting the activeParameter as I mentioned above. The signature.activeParameter should have precedence over result.activeParameter.
With your change, if you have a function with let's say, 3 arguments, and you try to add a 4th argument to it, the first argument gets re-highlighted:

[ray-x]

@henrique-ezcater
I strictly adhere to spec of 3.17

activeParameter:
* If omitted or the value lies outside the range of signatures[activeSignature].parameters
* defaults to 0 if the active signature has parameters.

And I also override activeParameter with signature.activeParameter if it present:

  if result.activeParameter ~= nil and result.activeParameter < #signature.parameters then
    activeParameter = result.activeParameter
  else
    activeParameter = 0
  end

  if signature.activeParameter ~= nil then
    activeParameter = signature.activeParameter
  end

I am avoiding doing hacky things for a specific LSP. I can do a special fix for pyright when I know the exact behaviour so I can know the fix will not break other LSP.

[henrique-ezcater]

Yeah, I've checked the code again and I noticed I had missed part of the logic. Seems like this is in accordance to the spec.
Thanks for the fix!