Merge pull request #26 from github/kill-whiny-nils

Kill whiny nils

activesupport/lib/active_support/whiny_nil.rb

-# Extensions to +nil+ which allow for more helpful error messages for people who
-# are new to Rails.
-#
-# Ruby raises NoMethodError if you invoke a method on an object that does not
-# respond to it:
-#
-#   $ ruby -e nil.destroy
-#   -e:1: undefined method `destroy' for nil:NilClass (NoMethodError)
-#
-# With these extensions, if the method belongs to the public interface of the
-# classes in NilClass::WHINERS the error message suggests which could be the
-# actual intended class:
-#
-#   $ script/runner nil.destroy 
-#   ...
-#   You might have expected an instance of ActiveRecord::Base.
-#   ...
-#
-# NilClass#id exists in Ruby 1.8 (though it is deprecated). Since +id+ is a fundamental
-# method of Active Record models NilClass#id is redefined as well to raise a RuntimeError
-# and warn the user. She probably wanted a model database identifier and the 4
-# returned by the original method could result in obscure bugs.
-#
-# The flag <tt>config.whiny_nils</tt> determines whether this feature is enabled.
-# By default it is on in development and test modes, and it is off in production
-# mode.
-class NilClass
-  WHINERS = [::Array]
-  WHINERS << ::ActiveRecord::Base if defined? ::ActiveRecord
-
-  METHOD_CLASS_MAP = Hash.new
-
-  WHINERS.each do |klass|
-    methods = klass.public_instance_methods - public_instance_methods
-    class_name = klass.name
-    methods.each { |method| METHOD_CLASS_MAP[method.to_sym] = class_name }
-  end
-
-  # Raises a RuntimeError when you attempt to call +id+ on +nil+.
-  def id
-    raise RuntimeError, "Called id for nil, which would mistakenly be 4 -- if you really wanted the id of nil, use object_id", caller
-  end
-
-  private
-    def method_missing(method, *args, &block)
-      # Ruby 1.9.2: disallow explicit coercion via method_missing.
-      if method == :to_ary || method == :to_str
-        super
-      elsif klass = METHOD_CLASS_MAP[method]
-        raise_nil_warning_for klass, method, caller
-      else
-        super
-      end
-    end
-
-    # Raises a NoMethodError when you attempt to call a method on +nil+.
-    def raise_nil_warning_for(class_name = nil, selector = nil, with_caller = nil)
-      message = "You have a nil object when you didn't expect it!"
-      message << "\nYou might have expected an instance of #{class_name}." if class_name
-      message << "\nThe error occurred while evaluating nil.#{selector}" if selector
-
-      raise NoMethodError, message, with_caller || caller
-    end
-end

activesupport/test/whiny_nil_test.rb

-# Stub to enable testing without Active Record
-module ActiveRecord
-  class Base
-    def save!
-    end
-  end
-end
-
-require 'abstract_unit'
-require 'active_support/whiny_nil'
-
-class WhinyNilTest < Test::Unit::TestCase
-  def test_unchanged
-    nil.method_thats_not_in_whiners
-  rescue NoMethodError => nme
-    assert(nme.message =~ /nil:NilClass/)
-  end
-
-  def test_active_record
-    nil.save!
-  rescue NoMethodError => nme
-    assert(!(nme.message =~ /nil:NilClass/))
-    assert_match(/nil\.save!/, nme.message)
-  end
-
-  def test_array
-    nil.each
-  rescue NoMethodError => nme
-    assert(!(nme.message =~ /nil:NilClass/))
-    assert_match(/nil\.each/, nme.message)
-  end
-
-  def test_id
-    nil.id
-  rescue RuntimeError => nme
-    assert(!(nme.message =~ /nil:NilClass/))
-  end
-
-  def test_no_to_ary_coercion
-    nil.to_ary
-  rescue NoMethodError => nme
-    assert(nme.message =~ /nil:NilClass/)
-  end
-
-  def test_no_to_str_coercion
-    nil.to_str
-  rescue NoMethodError => nme
-    assert(nme.message =~ /nil:NilClass/)
-  end
-end

railties/environments/development.rb

@@ -5,9 +5,6 @@
 # since you don't have to restart the webserver when you make code changes.
 config.cache_classes = false
 
-# Log error messages when you accidentally call methods on nil.
-config.whiny_nils = true
-
 # Show full error reports and disable caching
 config.action_controller.consider_all_requests_local = true
 config.action_controller.perform_caching             = false

railties/environments/test.rb

@@ -6,9 +6,6 @@
 # and recreated between test runs.  Don't rely on the data there!
 config.cache_classes = true
 
-# Log error messages when you accidentally call methods on nil.
-config.whiny_nils = true
-
 # Show full error reports and disable caching
 config.action_controller.consider_all_requests_local = true
 config.action_controller.perform_caching             = false
@@ -25,4 +22,4 @@
 # Use SQL instead of Active Record's schema dumper when creating the test database.
 # This is necessary if your schema can't be completely dumped by the schema dumper,
 # like if you have constraints or database-specific column types
-# config.active_record.schema_format = :sql
\ No newline at end of file
+# config.active_record.schema_format = :sql

railties/lib/initializer.rb

@@ -147,7 +147,6 @@ def process
       initialize_framework_logging
 
       initialize_dependency_mechanism
-      initialize_whiny_nils
 
       initialize_time_zone
       initialize_i18n
@@ -543,12 +542,6 @@ def initialize_dependency_mechanism
       ActiveSupport::Dependencies.mechanism = configuration.cache_classes ? :require : :load
     end
 
-    # Loads support for "whiny nil" (noisy warnings when methods are invoked
-    # on +nil+ values) if Configuration#whiny_nils is true.
-    def initialize_whiny_nils
-      require('active_support/whiny_nil') if configuration.whiny_nils
-    end
-
     # Sets the default value for Time.zone, and turns on ActiveRecord::Base#time_zone_aware_attributes.
     # If assigned value cannot be matched to a TimeZone, an exception will be raised.
     def initialize_time_zone
@@ -752,10 +745,6 @@ def load_once_paths=(paths)
     # The root of the application's views. (Defaults to <tt>app/views</tt>.)
     attr_accessor :view_path
 
-    # Set to +true+ if you want to be warned (noisily) when you try to invoke
-    # any method of +nil+. Set to +false+ for the standard Ruby behavior.
-    attr_accessor :whiny_nils
-
     # The list of plugins to load. If this is set to <tt>nil</tt>, all plugins will
     # be loaded. If this is set to <tt>[]</tt>, no plugins will be loaded. Otherwise,
     # plugins will be loaded in the order specified.
@@ -870,7 +859,6 @@ def initialize
       self.preload_frameworks           = default_preload_frameworks
       self.cache_classes                = default_cache_classes
       self.dependency_loading           = default_dependency_loading
-      self.whiny_nils                   = default_whiny_nils
       self.plugins                      = default_plugins
       self.plugin_paths                 = default_plugin_paths
       self.plugin_locators              = default_plugin_locators
@@ -1067,10 +1055,6 @@ def default_cache_classes
         true
       end
 
-      def default_whiny_nils
-        false
-      end
-
       def default_plugins
         nil
       end