class RubyLsp::Requests::Completion

suggests possible completions according to what the developer is typing.
The [completion](microsoft.github.io/language-server-protocol/specification#textDocument_completion)

def initialize(document, global_state, params, sorbet_level, dispatcher)

: ((RubyDocument | ERBDocument) document, GlobalState global_state, Hash[Symbol, untyped] params, SorbetLevel sorbet_level, Prism::Dispatcher dispatcher) -> void 
def initialize(document, global_state, params, sorbet_level, dispatcher)
  super()
  @target = nil #: Prism::Node?
  @dispatcher = dispatcher
  # Completion always receives the position immediately after the character that was just typed. Here we adjust it
  # back by 1, so that we find the right node
  char_position, _ = document.find_index_by_position(params[:position])
  char_position -= 1
  delegate_request_if_needed!(global_state, document, char_position)
  node_context = RubyDocument.locate(
    document.ast,
    char_position,
    node_types: [
      Prism::CallNode,
      Prism::ConstantReadNode,
      Prism::ConstantPathNode,
      Prism::GlobalVariableAndWriteNode,
      Prism::GlobalVariableOperatorWriteNode,
      Prism::GlobalVariableOrWriteNode,
      Prism::GlobalVariableReadNode,
      Prism::GlobalVariableTargetNode,
      Prism::GlobalVariableWriteNode,
      Prism::InstanceVariableReadNode,
      Prism::InstanceVariableAndWriteNode,
      Prism::InstanceVariableOperatorWriteNode,
      Prism::InstanceVariableOrWriteNode,
      Prism::InstanceVariableTargetNode,
      Prism::InstanceVariableWriteNode,
      Prism::ClassVariableAndWriteNode,
      Prism::ClassVariableOperatorWriteNode,
      Prism::ClassVariableOrWriteNode,
      Prism::ClassVariableReadNode,
      Prism::ClassVariableTargetNode,
      Prism::ClassVariableWriteNode,
    ],
    code_units_cache: document.code_units_cache,
  )
  @response_builder = ResponseBuilders::CollectionResponseBuilder
    .new #: ResponseBuilders::CollectionResponseBuilder[Interface::CompletionItem]
  Listeners::Completion.new(
    @response_builder,
    global_state,
    node_context,
    sorbet_level,
    dispatcher,
    document.uri,
    params.dig(:context, :triggerCharacter),
  )
  Addon.addons.each do |addon|
    addon.create_completion_listener(@response_builder, node_context, dispatcher, document.uri)
  end
  matched = node_context.node
  parent = node_context.parent
  return unless matched && parent
  @target = if parent.is_a?(Prism::ConstantPathNode) && matched.is_a?(Prism::ConstantReadNode)
    parent
  else
    matched
  end
end

def perform

: -> Array[Interface::CompletionItem]
@override 
def perform
  return [] unless @target
  @dispatcher.dispatch_once(@target)
  @response_builder.response
end

def provider

: -> Interface::CompletionOptions 
def provider
  Interface::CompletionOptions.new(
    resolve_provider: true,
    trigger_characters: ["/", "\"", "'", ":", "@", ".", "=", "<", "$"],
    completion_item: {
      labelDetailsSupport: true,
    },
  )
end