pry--pry/lib/pry/default_commands/context.rb

require "pry/default_commands/ls"

class Pry
  module DefaultCommands

    Context = Pry::CommandSet.new do
      import Ls

      command_class "cd" do
        description "Move into a new context (object or scope). Type `cd --help` for more information."

        banner <<-BANNER
          Usage: cd [OPTIONS] [--help]

          Move into new context (object or scope). As in unix shells use
          `cd ..` to go back and `cd /` to return to Pry top-level).
          Complex syntax (e.g cd ../@x/y) also supported.

          e.g: `cd @x`
          e.g: `cd ..
          e.g: `cd /`

          https://github.com/pry/pry/wiki/State-navigation#wiki-Changing_scope
        BANNER

        def process
          path   = arg_string.split(/\//)
          stack  = _pry_.binding_stack.dup

          # special case when we only get a single "/", return to root
          stack  = [stack.first] if path.empty?

          path.each do |context|
            begin
              case context.chomp
              when ""
                stack = [stack.first]
              when "::"
                stack.push(TOPLEVEL_BINDING)
              when "."
                next
              when ".."
                unless stack.size == 1
                  stack.pop
                end
              else
                stack.push(Pry.binding_for(stack.last.eval(context)))
              end

            rescue RescuableException => e
              output.puts "Bad object path: #{arg_string.chomp}. Failed trying to resolve: #{context}"
              output.puts e.inspect
              return
            end
          end

          _pry_.binding_stack = stack
        end
      end

      command "switch-to", "Start a new sub-session on a binding in the current stack (numbered by nesting)." do |selection|
        selection = selection.to_i

        if selection < 0 || selection > _pry_.binding_stack.size - 1
          raise CommandError, "Invalid binding index #{selection} - use `nesting` command to view valid indices."
        else
          Pry.start(_pry_.binding_stack[selection])
        end
      end

      command "nesting", "Show nesting information." do
        output.puts "Nesting status:"
        output.puts "--"
        _pry_.binding_stack.each_with_index do |obj, level|
          if level == 0
            output.puts "#{level}. #{Pry.view_clip(obj.eval('self'))} (Pry top level)"
          else
            output.puts "#{level}. #{Pry.view_clip(obj.eval('self'))}"
          end
        end
      end

      command "jump-to", "Jump to a binding further up the stack, popping all bindings below." do |break_level|
        break_level = break_level.to_i
        nesting_level = _pry_.binding_stack.size - 1

        case break_level
        when nesting_level
          output.puts "Already at nesting level #{nesting_level}"
        when (0...nesting_level)
          _pry_.binding_stack.slice!(break_level + 1, _pry_.binding_stack.size)

        else
          max_nest_level = nesting_level - 1
          output.puts "Invalid nest level. Must be between 0 and #{max_nest_level}. Got #{break_level}."
        end
      end

      command "exit-all", "End the current Pry session (popping all bindings) and returning to caller. Accepts optional return value. Aliases: !!@" do
        # clear the binding stack
        _pry_.binding_stack.clear

        # break out of the repl loop
        throw(:breakout, target.eval(arg_string))
      end

      alias_command "!!@", "exit-all"

      command_class "exit" do
        description "Pop the previous binding (does NOT exit program). Type `exit --help` for more information. Aliases: quit"

        banner <<-BANNER
          Usage:   exit [OPTIONS] [--help]
          Aliases: quit

          It can be useful to exit a context with a user-provided value. For
          instance an exit value can be used to determine program flow.

          e.g: `exit "pry this"`
          e.g: `exit`

          https://github.com/pry/pry/wiki/State-navigation#wiki-Exit_with_value
        BANNER

        command_options(
          :keep_retval => true
        )

        def process
          if _pry_.binding_stack.one?
            # when breaking out of top-level then behave like `exit-all`
            process_exit_all
          else
            # otherwise just pop a binding and return user supplied value
            process_pop_and_return
          end
        end

        def process_exit_all
          _pry_.binding_stack.clear
          throw(:breakout, target.eval(arg_string))
        end

        def process_pop_and_return
          popped_object = _pry_.binding_stack.pop.eval('self')

          # return a user-specified value if given otherwise return the object
          return target.eval(arg_string) unless arg_string.empty?
          popped_object
        end
      end

      alias_command "quit", "exit"

      command "exit-program", "End the current program. Aliases: quit-program, !!!" do
        Pry.save_history if Pry.config.history.should_save
        Kernel.exit target.eval(arg_string).to_i
      end

      alias_command "quit-program", "exit-program"
      alias_command "!!!", "exit-program"

      command "!pry", "Start a Pry session on current self; this even works mid multi-line expression." do
        target.pry
      end

      command "pry-backtrace", "Show the backtrace for the Pry session" do
        output.puts "\n#{text.bold('Backtrace:')}\n--\n"
        output.puts _pry_.backtrace
      end

      command "whereami", "Show the code context for the session. (whereami <n> shows <n> extra lines of code around the invocation line. Default: 5)" do |num|
        file = target.eval('__FILE__')
        line_num = target.eval('__LINE__')
        i_num = num ? num.to_i : 5

        if file != Pry.eval_path && (file =~ /(\(.*\))|<.*>/ || file == "" || file == "-e")
          raise CommandError, "Cannot find local context. Did you use `binding.pry`?"
        end

        set_file_and_dir_locals(file)

        method = Pry::Method.from_binding(target)
        method_description = method ? " in #{method.name_with_owner}" : ""
        output.puts "\n#{text.bold('From:')} #{file} @ line #{line_num}#{method_description}:\n\n"

        code = Pry::Code.from_file(file).around(line_num, i_num)
        output.puts code.with_line_numbers.with_marker(line_num)
        output.puts
      end

    end
  end
end