Contents

# frozen_string_literal: true

module RuboCop
  module Cop
    module RBS
      module Lint
        # Notice useless overload type parameters.
        #
        # @example default
        #   # bad
        #   def foo: [T] () -> void
        #
        #   # good
        #   def foo: [T] (T) -> T
        class UselessOverloadTypeParams < RuboCop::RBS::CopBase
          MSG = 'Useless overload type variable - `%<variable>s`.'

          def on_rbs_def(decl)
            decl.overloads.each do |overload|
              next if overload.method_type.type_params.empty?

              type_params = overload.method_type.type_params.dup
              map = type_params.to_h { |param| [param.name, param] }
              type_params.each do |type_param|
                if type_param.upper_bound
                  used_variable_in_type(type_param.upper_bound) do |var|
                    map.delete(var.name)
                  end
                end
              end

              overload.method_type.each_type do |type|
                used_variable_in_type(type) do |var|
                  map.delete(var.name)
                end
              end
              next if map.empty?

              map.each do |name, type_param|
                next unless type_param.location

                t = location_to_range(type_param.location[:name])
                add_offense(t, message: format(MSG, variable: name))
              end
            end
          end

          def used_variable_in_type(type, &block)
            case type
            when ::RBS::Types::Variable
              yield type
            else
              type.each_type do |t|
                used_variable_in_type(t, &block)
              end
            end
          end
        end
      end
    end
  end
end

Version data entries

5 entries across 5 versions & 1 rubygems

Version	Path
rubocop-on-rbs-1.2.0	lib/rubocop/cop/rbs/lint/useless_overload_type_params.rb
rubocop-on-rbs-1.1.0	lib/rubocop/cop/rbs/lint/useless_overload_type_params.rb
rubocop-on-rbs-1.0.0	lib/rubocop/cop/rbs/lint/useless_overload_type_params.rb
rubocop-on-rbs-0.9.0	lib/rubocop/cop/rbs/lint/useless_overload_type_params.rb
rubocop-on-rbs-0.8.0	lib/rubocop/cop/rbs/lint/useless_overload_type_params.rb