pry--pry/lib/pry/default_commands/whereami.rb

class Pry
  module DefaultCommands
    Whereami = Pry::CommandSet.new do
      create_command "whereami" do
        description "Show code surrounding the current context."
        group 'Context'
        banner <<-BANNER
          Usage: whereami [-q] [N]

          Describe the current location. If you use `binding.pry` inside a
          method then whereami will print out the source for that method.

          If a number is passed, then N lines before and after the current line
          will be shown instead of the method itself.

          The `-q` flag can be used to suppress error messages in the case that
          there's no code to show. This is used by pry in the default
          before_session hook to show you when you arrive at a `binding.pry`.

          When pry was started on an Object and there is no associated method,
          whereami will instead output a brief description of the current
          object.
        BANNER

        def setup
          @method = Pry::Method.from_binding(target)
          @file = target.eval('__FILE__')
          @line = target.eval('__LINE__')
        end

        def options(opt)
          opt.on :q, :quiet, "Don't display anything in case of an error"
        end

        def code
          @code ||= if show_method?
                      Pry::Code.from_method(@method)
                    else
                      Pry::Code.from_file(@file).around(@line, window_size)
                    end
        end

        def location
          "#{@file} @ line #{show_method? ? @method.source_line : @line} #{@method && @method.name_with_owner}"
        end

        def process
          if opts.quiet? && (internal_binding?(target) || !code?)
            return
          elsif internal_binding?(target)
            if target_self == TOPLEVEL_BINDING.eval("self")
              output.puts "At the top level."
            else
              output.puts "Inside #{Pry.view_clip(target_self)}."
            end
            return
          end

          set_file_and_dir_locals(@file)

          output.puts "\n#{text.bold('From:')} #{location}:\n\n"
          output.puts code.with_line_numbers.with_marker(@line)
          output.puts
        end

        private

        def show_method?
          args.empty? && @method && @method.source? && @method.source_range.count < 20 &&
          # These checks are needed in case of an eval with a binding and file/line
          # numbers set to outside the function. As in rails' use of ERB.
          @method.source_file == @file && @method.source_range.include?(@line)
        end

        def code?
          !!code
        rescue MethodSource::SourceNotFoundError
          false
        end

        def window_size
          if args.empty?
            Pry.config.default_window_size
          else
            args.first.to_i
          end
        end
      end
    end
  end
end