Class: RubyLsp::Requests::SignatureHelp

Inherits:
Request
  • Object
show all
Extended by:
T::Generic, T::Sig
Defined in:
lib/ruby_lsp/requests/signature_help.rb

Overview

![Signature help demo](../../signature_help.gif)

The [signature help request](microsoft.github.io/language-server-protocol/specification#textDocument_signatureHelp) displays information about the parameters of a method as you type an invocation.

Currently only supports methods invoked directly on ‘self` without taking inheritance into account.

# Example

“‘ruby class Foo

def bar(a, b, c)
end

def baz
  bar( # -> Signature help will show the parameters of `bar`
end

“‘

Constant Summary collapse

ResponseType = 
type_member { { fixed: T.nilable(T.any(Interface::SignatureHelp, T::Hash[Symbol, T.untyped])) } }

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(document, index, position, context, dispatcher) ⇒ SignatureHelp

Returns a new instance of SignatureHelp.



54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
 
# File 'lib/ruby_lsp/requests/signature_help.rb', line 54

def initialize(document, index, position, context, dispatcher)
  super()
  current_signature = context && context[:activeSignatureHelp]
  target, parent, nesting = document.locate_node(
    { line: position[:line], character: position[:character] - 2 },
    node_types: [Prism::CallNode],
  )

  # If we're typing a nested method call (e.g.: `foo(bar)`), then we may end up locating `bar` as the target
  # method call incorrectly. To correct that, we check if there's an active signature with the same name as the
  # parent node and then replace the target
  if current_signature && parent.is_a?(Prism::CallNode)
    active_signature = current_signature[:activeSignature] || 0

    if current_signature.dig(:signatures, active_signature, :label)&.start_with?(parent.message)
      target = parent
    end
  end

  @target = T.let(target, T.nilable(Prism::Node))
  @dispatcher = dispatcher
  @listener = T.let(Listeners::SignatureHelp.new(nesting, index, dispatcher), Listener[ResponseType])
end

Class Method Details

.provider ⇒ Object 



35
36
37
38
39
40
 
# File 'lib/ruby_lsp/requests/signature_help.rb', line 35

def provider
  # Identifier characters are automatically included, such as A-Z, a-z, 0-9, _, * or :
  Interface::SignatureHelpOptions.new(
    trigger_characters: ["(", " ", ","],
  )
end

Instance Method Details

#perform ⇒ Object 



79
80
81
82
83
84
 
# File 'lib/ruby_lsp/requests/signature_help.rb', line 79

def perform
  return unless @target

  @dispatcher.dispatch_once(@target)
  @listener.response
end