inflector.rb in elastic-apm-0.7.0

- old
+ new

@@ -1,32 +1,35 @@
+# frozen_string_literal: true
+
 module ElasticAPM
+  # rubocop:disable all
   module Util
-    # @api private
+    # From https://github.com/rails/rails/blob/v5.2.0/activesupport/lib/active_support/inflector/methods.rb#L254-L332
     module Inflector
-      # rubocop:disable all
-      # From https://github.com/rails/rails/blob/861b70e92f4a1fc0e465ffcf2ee62680519c8f6f/activesupport/lib/active_support/inflector/methods.rb#L249
+      extend self
+
       #
       # Tries to find a constant with the name specified in the argument string.
       #
-      #   'Module'.constantize     # => Module
-      #   'Test::Unit'.constantize # => Test::Unit
+      #   constantize('Module')   # => Module
+      #   constantize('Foo::Bar') # => Foo::Bar
       #
       # The name is assumed to be the one of a top-level constant, no matter
       # whether it starts with "::" or not. No lexical context is taken into
       # account:
       #
       #   C = 'outside'
       #   module M
       #     C = 'inside'
-      #     C               # => 'inside'
-      #     'C'.constantize # => 'outside', same as ::C
+      #     C                # => 'inside'
+      #     constantize('C') # => 'outside', same as ::C
       #   end
       #
       # NameError is raised when the name is not in CamelCase or the constant is
       # unknown.
-      def self.constantize(camel_cased_word)
-        names = camel_cased_word.split('::')
+      def constantize(camel_cased_word)
+        names = camel_cased_word.split("::".freeze)
 
         # Trigger a built-in NameError exception including the ill-formed constant in the message.
         Object.const_get(camel_cased_word) if names.empty?
 
         # Remove the first blank element in case of '::ClassName' notation.
@@ -40,20 +43,51 @@
             next candidate if constant.const_defined?(name, false)
             next candidate unless Object.const_defined?(name)
 
             # Go down the ancestors to check if it is owned directly. The check
             # stops when we reach Object or the end of ancestors tree.
-            constant = constant.ancestors.inject do |const, ancestor|
+            constant = constant.ancestors.inject(constant) do |const, ancestor|
               break const    if ancestor == Object
               break ancestor if ancestor.const_defined?(name, false)
               const
             end
 
             # owner is in Object, so raise
             constant.const_get(name, false)
           end
         end
       end
-      # rubocop:enable all
+
+      # Tries to find a constant with the name specified in the argument string.
+      #
+      #   safe_constantize('Module')   # => Module
+      #   safe_constantize('Foo::Bar') # => Foo::Bar
+      #
+      # The name is assumed to be the one of a top-level constant, no matter
+      # whether it starts with "::" or not. No lexical context is taken into
+      # account:
+      #
+      #   C = 'outside'
+      #   module M
+      #     C = 'inside'
+      #     C                     # => 'inside'
+      #     safe_constantize('C') # => 'outside', same as ::C
+      #   end
+      #
+      # +nil+ is returned when the name is not in CamelCase or the constant (or
+      # part of it) is unknown.
+      #
+      #   safe_constantize('blargle')                  # => nil
+      #   safe_constantize('UnknownModule')            # => nil
+      #   safe_constantize('UnknownModule::Foo::Bar')  # => nil
+      def safe_constantize(camel_cased_word)
+        constantize(camel_cased_word)
+      rescue NameError => e
+        raise if e.name && !(camel_cased_word.to_s.split("::").include?(e.name.to_s) ||
+                             e.name.to_s == camel_cased_word.to_s)
+      rescue ArgumentError => e
+        raise unless /not missing constant #{const_regexp(camel_cased_word)}!$/.match?(e.message)
+      end
     end
   end
+  # rubocop:enable all
 end