Class: IRB::Command::Debug

Inherits:
Base show all
Defined in:
lib/irb/command/debug.rb

Direct Known Subclasses

DebugCommand

Instance Attribute Summary

Attributes inherited from Base

#irb_context

Instance Method Summary collapse

Methods inherited from Base

category, description, execute, help_message, #initialize

Constructor Details

This class inherits a constructor from IRB::Command::Base

Instance Method Details

#execute(_arg) ⇒ Object 



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# File 'lib/irb/command/debug.rb', line 11

def execute(_arg)
  execute_debug_command
end

#execute_debug_command(pre_cmds: nil, do_cmds: nil) ⇒ Object 



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# File 'lib/irb/command/debug.rb', line 15

def execute_debug_command(pre_cmds: nil, do_cmds: nil)
  pre_cmds = pre_cmds&.rstrip
  do_cmds = do_cmds&.rstrip

  if irb_context.with_debugger
    # If IRB is already running with a debug session, throw the command and IRB.debug_readline will pass it to the debugger.
    if cmd = pre_cmds || do_cmds
      throw :IRB_EXIT, cmd
    else
      puts "IRB is already running with a debug session."
      return
    end
  else
    # If IRB is not running with a debug session yet, then:
    # 1. Check if the debugging command is run from a `binding.irb` call.
    # 2. If so, try setting up the debug gem.
    # 3. Insert a debug breakpoint at `Irb#debug_break` with the intended command.
    # 4. Exit the current Irb#run call via `throw :IRB_EXIT`.
    # 5. `Irb#debug_break` will be called and trigger the breakpoint, which will run the intended command.
    unless irb_context.from_binding?
      puts "Debugging commands are only available when IRB is started with binding.irb"
      return
    end

    if IRB.respond_to?(:JobManager)
      warn "Can't start the debugger when IRB is running in a multi-IRB session."
      return
    end

    unless IRB::Debug.setup(irb_context.irb)
      puts <<~MSG
        You need to install the debug gem before using this command.
        If you use `bundle exec`, please add `gem "debug"` into your Gemfile.
      MSG
      return
    end

    IRB::Debug.insert_debug_break(pre_cmds: pre_cmds, do_cmds: do_cmds)

    # exit current Irb#run call
    throw :IRB_EXIT
  end
end