diff options
Diffstat (limited to 'activesupport/lib/active_support/whiny_nil.rb')
-rw-r--r-- | activesupport/lib/active_support/whiny_nil.rb | 60 |
1 files changed, 0 insertions, 60 deletions
diff --git a/activesupport/lib/active_support/whiny_nil.rb b/activesupport/lib/active_support/whiny_nil.rb deleted file mode 100644 index 577db5018e..0000000000 --- a/activesupport/lib/active_support/whiny_nil.rb +++ /dev/null @@ -1,60 +0,0 @@ -# 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: -# -# $ rails 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 - METHOD_CLASS_MAP = Hash.new - - def self.add_whiner(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 - - add_whiner ::Array - - # Raises a RuntimeError when you attempt to call +id+ on +nil+. - def id - raise RuntimeError, "Called id for nil, which would mistakenly be #{object_id} -- if you really wanted the id of nil, use object_id", caller - end - - private - def method_missing(method, *args) - if 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 |