Class: Pry::REPLFileLoader

Inherits:
Object show all
Defined in:
lib/pry/repl_file_loader.rb

Overview

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.

Instance Method Summary collapse

Constructor Details

#initialize(file_name) ⇒ REPLFileLoader

Returns a new instance of REPLFileLoader.



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# File 'lib/pry/repl_file_loader.rb', line 15

def initialize(file_name)
  full_name = File.expand_path(file_name)
  raise "No such file: #{full_name}" unless File.exist?(full_name)

  define_additional_commands
  @content = File.read(full_name)
end

Instance Method Details

#define_additional_commands ⇒ Object

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



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# File 'lib/pry/repl_file_loader.rb', line 59

def define_additional_commands
  s = self

  Pry::Commands.command "make-interactive", "Make the session interactive" do
    s.interactive_mode(pry_instance)
  end

  Pry::Commands.command(
    "load-file", "Load another file through the repl"
  ) do |file_name|
    s.non_interactive_mode(pry_instance, File.read(File.expand_path(file_name)))
  end
end

#interactive_mode(pry_instance) ⇒ Object

Switch to interactive mode, i.e take input from the user and use the regular print and exception handlers.

Parameters:

  • pry_instance (Pry) —

    the Pry instance to make interactive.



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# File 'lib/pry/repl_file_loader.rb', line 26

def interactive_mode(pry_instance)
  pry_instance.config.input = Pry.config.input
  pry_instance.config.print = Pry.config.print
  pry_instance.config.exception_handler = Pry.config.exception_handler
  Pry::REPL.new(pry_instance).start
end

#load ⇒ Object

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



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# File 'lib/pry/repl_file_loader.rb', line 75

def load
  non_interactive_mode(Pry.new, @content)
end

#non_interactive_mode(pry_instance, content) ⇒ Object

Switch to non-interactive mode. Essentially this means there is no result output and that the session becomes interactive when an exception is encountered.

Parameters:

  • pry_instance (Pry) —

    the Pry instance to make non-interactive.



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# File 'lib/pry/repl_file_loader.rb', line 37

def non_interactive_mode(pry_instance, content)
  pry_instance.print = proc {}
  pry_instance.exception_handler = proc do |o, _e, p|
    p.run_command "cat --ex"
    o.puts "...exception encountered, going interactive!"
    interactive_mode(pry_instance)
  end

  content.lines.each do |line|
    break unless pry_instance.eval line, generated: true
  end

  return if pry_instance.eval_string.empty?

  pry_instance.output.puts(
    "#{pry_instance.eval_string}...exception encountered, going interactive!"
  )
  interactive_mode(pry_instance)
end