activesupport/lib/active_support/core_ext/name_error.rb
# frozen_string_literal: true
class NameError
# Extract the name of the missing constant from the exception message.
#
# begin
# HelloWorld
# rescue NameError => e
# e.missing_name
# end
# # => "HelloWorld"
def missing_name
# Since ruby v2.3.0 `did_you_mean` gem is loaded by default.
# It extends NameError#message with spell corrections which are SLOW.
# We should use original_message message instead.
message = respond_to?(:original_message) ? original_message : self.message
return unless message.start_with?("uninitialized constant ")
receiver = begin
self.receiver
rescue ArgumentError
nil
end
if receiver == Object
name.to_s
elsif receiver
"#{real_mod_name(receiver)}::#{self.name}"
else
if match = message.match(/((::)?([A-Z]\w*)(::[A-Z]\w*)*)$/)
match[1]
end
end
end
# Was this exception raised because the given name was missing?
#
# begin
# HelloWorld
# rescue NameError => e
# e.missing_name?("HelloWorld")
# end
# # => true
def missing_name?(name)
if name.is_a? Symbol
self.name == name
else
missing_name == name.to_s
end
end
private
UNBOUND_METHOD_MODULE_NAME = Module.instance_method(:name)
private_constant :UNBOUND_METHOD_MODULE_NAME
def real_mod_name(mod)
UNBOUND_METHOD_MODULE_NAME.bind_call(mod)
end
end