dependencies.rb in activesupport-6.0.0.beta1

- old
+ new

@@ -77,10 +77,16 @@
 
     # An array of constant names that need to be unloaded on every request. Used
     # to allow arbitrary constants to be marked for unloading.
     mattr_accessor :explicitly_unloadable_constants, default: []
 
+    # The logger used when tracing autoloads.
+    mattr_accessor :logger
+
+    # If true, trace autoloads with +logger.debug+.
+    mattr_accessor :verbose, default: false
+
     # The WatchStack keeps a stack of the modules being watched as files are
     # loaded. If a file in the process of being loaded (parent.rb) triggers the
     # load of another file (child.rb) the stack will ensure that child.rb
     # handles the new constants.
     #
@@ -138,11 +144,11 @@
             namespace_constants.concat(new_constants)
           end
 
           # Normalize the list of new constants, and add them to the list we will return
           new_constants.each do |suffix|
-            constants << ([namespace, suffix] - ["Object"]).join("::".freeze)
+            constants << ([namespace, suffix] - ["Object"]).join("::")
           end
         end
         constants
       ensure
         # A call to new_constants is always called after a call to watch_namespaces
@@ -347,11 +353,11 @@
         remove_unloadable_constants!
       end
     end
 
     def require_or_load(file_name, const_path = nil)
-      file_name = $` if file_name =~ /\.rb\z/
+      file_name = file_name.chomp(".rb")
       expanded = File.expand_path(file_name)
       return if loaded.include?(expanded)
 
       Dependencies.load_interlock do
         # Maybe it got loaded while we were waiting for our lock:
@@ -397,20 +403,20 @@
 
     # Given +path+, a filesystem path to a ruby file, return an array of
     # constant paths which would cause Dependencies to attempt to load this
     # file.
     def loadable_constants_for_path(path, bases = autoload_paths)
-      path = $` if path =~ /\.rb\z/
+      path = path.chomp(".rb")
       expanded_path = File.expand_path(path)
       paths = []
 
       bases.each do |root|
         expanded_root = File.expand_path(root)
         next unless expanded_path.start_with?(expanded_root)
 
         root_size = expanded_root.size
-        next if expanded_path[root_size] != ?/.freeze
+        next if expanded_path[root_size] != ?/
 
         nesting = expanded_path[(root_size + 1)..-1]
         paths << nesting.camelize unless nesting.blank?
       end
 
@@ -418,11 +424,11 @@
       paths
     end
 
     # Search for a file in autoload_paths matching the provided suffix.
     def search_for_file(path_suffix)
-      path_suffix = path_suffix.sub(/(\.rb)?$/, ".rb".freeze)
+      path_suffix += ".rb" unless path_suffix.ends_with?(".rb")
 
       autoload_paths.each do |root|
         path = File.join(root, path_suffix)
         return path if File.file? path
       end
@@ -452,10 +458,11 @@
     # set of constants that are to be unloaded.
     def autoload_module!(into, const_name, qualified_name, path_suffix)
       return nil unless base_path = autoloadable_module?(path_suffix)
       mod = Module.new
       into.const_set const_name, mod
+      log("constant #{qualified_name} autoloaded (module autovivified from #{File.join(base_path, path_suffix)})")
       autoloaded_constants << qualified_name unless autoload_once_paths.include?(base_path)
       autoloaded_constants.uniq!
       mod
     end
 
@@ -493,30 +500,35 @@
     def load_missing_constant(from_mod, const_name)
       unless qualified_const_defined?(from_mod.name) && Inflector.constantize(from_mod.name).equal?(from_mod)
         raise ArgumentError, "A copy of #{from_mod} has been removed from the module tree but is still active!"
       end
 
-      qualified_name = qualified_name_for from_mod, const_name
+      qualified_name = qualified_name_for(from_mod, const_name)
       path_suffix = qualified_name.underscore
 
       file_path = search_for_file(path_suffix)
 
       if file_path
         expanded = File.expand_path(file_path)
-        expanded.sub!(/\.rb\z/, "".freeze)
+        expanded.sub!(/\.rb\z/, "")
 
         if loading.include?(expanded)
           raise "Circular dependency detected while autoloading constant #{qualified_name}"
         else
           require_or_load(expanded, qualified_name)
-          raise LoadError, "Unable to autoload constant #{qualified_name}, expected #{file_path} to define it" unless from_mod.const_defined?(const_name, false)
-          return from_mod.const_get(const_name)
+
+          if from_mod.const_defined?(const_name, false)
+            log("constant #{qualified_name} autoloaded from #{expanded}.rb")
+            return from_mod.const_get(const_name)
+          else
+            raise LoadError, "Unable to autoload constant #{qualified_name}, expected #{file_path} to define it"
+          end
         end
       elsif mod = autoload_module!(from_mod, const_name, qualified_name, path_suffix)
         return mod
-      elsif (parent = from_mod.parent) && parent != from_mod &&
-            ! from_mod.parents.any? { |p| p.const_defined?(const_name, false) }
+      elsif (parent = from_mod.module_parent) && parent != from_mod &&
+            ! from_mod.module_parents.any? { |p| p.const_defined?(const_name, false) }
         # If our parents do not have a constant named +const_name+ then we are free
         # to attempt to load upwards. If they do have such a constant, then this
         # const_missing must be due to from_mod::const_name, which should not
         # return constants from from_mod's parents.
         begin
@@ -556,10 +568,11 @@
     #
     # The callback implementation should be restricted to cleaning up caches, etc.
     # as the environment will be in an inconsistent state, e.g. other constants
     # may have already been unloaded and not accessible.
     def remove_unloadable_constants!
+      log("removing unloadable constants")
       autoloaded_constants.each { |const| remove_constant const }
       autoloaded_constants.clear
       Reference.clear!
       explicitly_unloadable_constants.each { |const| remove_constant const }
     end
@@ -744,9 +757,13 @@
       begin
         parent.instance_eval { remove_const to_remove }
       rescue NameError
         # The constant is no longer reachable, just skip it.
       end
+    end
+
+    def log(message)
+      logger.debug("autoloading: #{message}") if logger && verbose
     end
   end
 end
 
 ActiveSupport::Dependencies.hook!