lib/pry/commands/ls/jruby_hacks.rb

Summary

Maintainability
A
0 mins
Test Coverage
# frozen_string_literal: true

class Pry
  class Command
    class Ls < Pry::ClassCommand
      module JRubyHacks
        private

        # JRuby creates lots of aliases for methods imported from java in an attempt
        # to make life easier for ruby programmers.  (e.g. getFooBar becomes
        # get_foo_bar and foo_bar, and maybe foo_bar? if it returns a Boolean). The
        # full transformations are in the assignAliases method of:
        # https://github.com/jruby/jruby/blob/master/src/org/jruby/javasupport/JavaClass.java
        #
        # This has the unfortunate side-effect of making the output of ls even more
        # incredibly verbose than it normally would be for these objects; and so we
        # filter out all but the nicest of these aliases here.
        #
        # TODO: This is a little bit vague, better heuristics could be used.
        #       JRuby also has a lot of scala-specific logic, which we don't copy.
        def trim_jruby_aliases(methods)
          grouped = methods.group_by do |m|
            m.name.sub(/\A(is|get|set)(?=[A-Z_])/, '').gsub(/[_?=]/, '').downcase
          end

          grouped.flat_map do |_key, values|
            values = values.sort_by do |m|
              rubbishness(m.name)
            end

            found = []
            values.select do |x|
              (found.none? { |y| x == y }) && found << x
            end
          end
        end

        # When removing jruby aliases, we want to keep the alias that is
        # "least rubbish" according to this metric.
        def rubbishness(name)
          name.each_char.map do |x|
            case x
            when /[A-Z]/
              1
            when '?', '=', '!'
              -2
            else
              0
            end
          end.inject(&:+) + (name.size / 100.0)
        end
      end
    end
  end
end