pry.rb: Move all exception specific code to its own file

This finishes up Robert Gleeson's refactoring. A sole file for
RescuableException doesn't make much sense, since we have a few more
exceptions left behind.

lib/pry.rb

@@ -2,11 +2,13 @@
 # MIT License
 #
 require 'pp'
+
+require 'pry/input_lock'
+require 'pry/exceptions'
+require 'pry/helpers/base_helpers'
+require 'pry/hooks'
+
 class Pry
-  require 'pry/input_lock'
-  require 'pry/rescuable_exception'
-  require 'pry/helpers/base_helpers'
-  require 'pry/hooks'
 
   # The default hooks - display messages when beginning and ending Pry sessions.
   DEFAULT_HOOKS = Pry::Hooks.new.add_hook(:before_session, :default) do |out, target, _pry_|
@@ -143,56 +145,15 @@ class Pry
   # your process has changed directory since boot. [Issue #675]
   INITIAL_PWD = Dir.pwd
 
-  # An Exception Tag (cf. Exceptional Ruby) that instructs Pry to show the error in
-  # a more user-friendly manner. This should be used when the exception happens within
-  # Pry itself as a direct consequence of the user typing something wrong.
-  #
-  # This allows us to distinguish between the user typing:
-  #
-  # pry(main)> def )
-  # SyntaxError: unexpected )
-  #
-  # pry(main)> method_that_evals("def )")
-  # SyntaxError: (eval):1: syntax error, unexpected ')'
-  # from ./a.rb:2 in `eval'
-  module UserError; end
-
-  # Catches SecurityErrors if $SAFE is set
-  module TooSafeException
-    def self.===(exception)
-      $SAFE > 0 && SecurityError === exception
-    end
-  end
-
-  # When we try to get a binding for an object, we try to define a method on
-  # that Object's singleton class. This doesn't work for "frozen" Object's, and
-  # the exception is just a vanilla RuntimeError.
-  module FrozenObjectException
-    def self.===(exception)
-      ["can't modify frozen class/module", "can't modify frozen Class"].include? exception.message
-    end
-  end
-
-  # Don't catch these exceptions
-  DEFAULT_EXCEPTION_WHITELIST = [SystemExit, SignalException, Pry::TooSafeException]
-
-  # CommandErrors are caught by the REPL loop and displayed to the user. They
-  # indicate an exceptional condition that's fatal to the current command.
-  class CommandError < StandardError; end
-  class MethodNotFound < CommandError; end
-
-  # indicates obsolete API
-  class ObsoleteError < StandardError; end
-
   # This is to keep from breaking under Rails 3.2 for people who are doing that
   # IRB = Pry thing.
-  module ExtendCommandBundle
-  end
+  module ExtendCommandBundle; end
+
 end
 
 if Pry::Helpers::BaseHelpers.mri_18?
   begin
-  require 'ruby18_source_location'
+    require 'ruby18_source_location'
   rescue LoadError
   end
 end
@@ -229,9 +190,9 @@ end
 if Pry::Helpers::BaseHelpers.windows? && !Pry::Helpers::BaseHelpers.windows_ansi?
   begin
     require 'win32console'
-  # The mswin and mingw versions of pry require win32console, so this should
-  # only fail on jruby (where win32console doesn't work).
-  # Instead we'll recommend ansicon, which does.
+    # The mswin and mingw versions of pry require win32console, so this should
+    # only fail on jruby (where win32console doesn't work).
+    # Instead we'll recommend ansicon, which does.
   rescue LoadError
     warn "For a better pry experience, please use ansicon: http://adoxa.3eeweb.com/ansicon/"
   end

lib/pry/exceptions.rb

@@ -0,0 +1,77 @@
+class Pry
+
+  # As a REPL, we often want to catch any unexpected exceptions that may have
+  # been raised; however we don't want to go overboard and prevent the user
+  # from exiting Pry when they want to.
+  module RescuableException
+    def self.===(exception)
+      case exception
+        # Catch when the user hits ^C (Interrupt < SignalException), and assume
+        # that they just wanted to stop the in-progress command (just like bash
+        # etc.)
+      when Interrupt
+        true
+        # Don't catch signals (particularly not SIGTERM) as these are unlikely
+        # to be intended for pry itself. We should also make sure that
+        # Kernel#exit works.
+      when *Pry.config.exception_whitelist
+        false
+        # All other exceptions will be caught.
+      else
+        true
+      end
+    end
+  end
+
+  # Catches SecurityErrors if $SAFE is set
+  module Pry::TooSafeException
+    def self.===(exception)
+      $SAFE > 0 && SecurityError === exception
+    end
+  end
+
+  # An Exception Tag (cf. Exceptional Ruby) that instructs Pry to show the error
+  # in a more user-friendly manner. This should be used when the exception
+  # happens within Pry itself as a direct consequence of the user typing
+  # something wrong.
+  #
+  # This allows us to distinguish between the user typing:
+  #
+  # pry(main)> def )
+  # SyntaxError: unexpected )
+  #
+  # pry(main)> method_that_evals("def )")
+  # SyntaxError: (eval):1: syntax error, unexpected ')'
+  # from ./a.rb:2 in `eval'
+  module UserError; end
+
+  # When we try to get a binding for an object, we try to define a method on
+  # that Object's singleton class. This doesn't work for "frozen" Object's, and
+  # the exception is just a vanilla RuntimeError.
+  module FrozenObjectException
+    def self.===(exception)
+      ["can't modify frozen class/module",
+       "can't modify frozen Class",
+      ].include?(exception.message)
+    end
+  end
+
+  # Don't catch these exceptions
+  DEFAULT_EXCEPTION_WHITELIST = [SystemExit,
+                                 SignalException,
+                                 Pry::TooSafeException]
+
+  # CommandErrors are caught by the REPL loop and displayed to the user. They
+  # indicate an exceptional condition that's fatal to the current command.
+  class CommandError < StandardError; end
+  class MethodNotFound < CommandError; end
+
+  # indicates obsolete API
+  class ObsoleteError < StandardError; end
+
+  # This is to keep from breaking under Rails 3.2 for people who are doing that
+  # IRB = Pry thing.
+  module ExtendCommandBundle
+  end
+
+end

lib/pry/rescuable_exception.rb

@@ -1,20 +0,0 @@
-# As a REPL, we often want to catch any unexpected exceptions that may have
-# been raised; however we don't want to go overboard and prevent the user
-# from exiting Pry when they want to.
-module Pry::RescuableException
-  def self.===(exception)
-    case exception
-      # Catch when the user hits ^C (Interrupt < SignalException), and assume
-      # that they just wanted to stop the in-progress command (just like bash etc.)
-    when Interrupt
-      true
-      # Don't catch signals (particularly not SIGTERM) as these are unlikely to be
-      # intended for pry itself. We should also make sure that Kernel#exit works.
-    when *Pry.config.exception_whitelist
-      false
-      # All other exceptions will be caught.
-    else
-      true
-    end
-  end
-end