class Pry::REPLFileLoader

A class to manage the loading of files through the REPL loop. This is an interesting trick as it processes your file as if it was user input in an interactive session. As a result, all Pry commands are available, and they are executed non-interactively. Furthermore the session becomes interactive when the repl loop processes a 'make-interactive' command in the file. The session also becomes interactive when an exception is encountered, enabling you to fix the error before returning to non-interactive processing with the 'make-non-interactive' command.

Public Class Methods

new(file_name) click to toggle source
# File lib/pry/repl_file_loader.rb, line 14
def initialize(file_name)
  full_name = File.expand_path(file_name)
  raise RuntimeError, "No such file: #{full_name}" if !File.exists?(full_name)

  @content = StringIO.new(File.read(full_name))
end

Public Instance Methods

define_additional_commands() click to toggle source

Define a few extra commands useful for flipping back & forth between interactive/non-interactive modes

# File lib/pry/repl_file_loader.rb, line 45
def define_additional_commands
  s = self

  Pry::Commands.command "make-interactive", "Make the session interactive" do
    _pry_.input_stack.push _pry_.input
    s.interactive_mode(_pry_)
  end

  Pry::Commands.command "make-non-interactive", "Make the session non-interactive" do
    _pry_.input = _pry_.input_stack.pop
    s.non_interactive_mode(_pry_)
  end

  Pry::Commands.command "load-file", "Load another file through the repl" do |file_name|
    content = StringIO.new(File.read(File.expand_path(file_name)))
    _pry_.input_stack.push(_pry_.input)
    _pry_.input = content
  end
end
interactive_mode(_pry_) click to toggle source

Switch to interactive mode, i.e take input from the user and use the regular print and exception handlers. @param [Pry] pry the Pry instance to make interactive.

# File lib/pry/repl_file_loader.rb, line 24
def interactive_mode(_pry_)
  _pry_.input = Pry.config.input
  _pry_.print = Pry.config.print
  _pry_.exception_handler = Pry.config.exception_handler
end
load() click to toggle source

Actually load the file through the REPL by setting file content as the REPL input stream.

# File lib/pry/repl_file_loader.rb, line 67
def load
  Pry.initial_session_setup
  define_additional_commands

  Pry.config.hooks.add_hook(:when_started, :start_non_interactively) do |o, t, _pry_|
    non_interactive_mode(_pry_)
  end

  Pry.start(Pry.toplevel_binding,
            :input => @content,
            :input_stack => [StringIO.new("exit-all\n")])
end
non_interactive_mode(_pry_) click to toggle source

Switch to non-interactive mode. Essentially this means there is no result output and that the session becomes interactive when an exception is encountered. @param [Pry] pry the Pry instance to make non-interactive.

# File lib/pry/repl_file_loader.rb, line 34
def non_interactive_mode(_pry_)
  _pry_.print = proc {}
  _pry_.exception_handler = proc do |o, e, _pry_|
    _pry_.run_command "cat --ex"
    o.puts "...exception encountered, going interactive!"
    interactive_mode(_pry_)
  end
end