Merge branch 'master' into bug/filtered_parameters_class

66 files changed, 2224 insertions, 1395 deletions

diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md
index 3ce4a0bbab..ab5237488a 100644
--- a/activesupport/CHANGELOG.md
+++ b/activesupport/CHANGELOG.md
@@ -1,3 +1,87 @@
+*   Default `ActiveSupport::MessageEncryptor` to use AES 256 GCM encryption.
+
+    On for new Rails 5.2 apps. Upgrading apps can find the config as a new
+    framework default.
+
+    *Assain Jaleel*
+
+*   Cache: `write_multi`
+
+        Rails.cache.write_multi foo: 'bar', baz: 'qux'
+
+    Plus faster fetch_multi with stores that implement `write_multi_entries`.
+    Keys that aren't found may be written to the cache store in one shot
+    instead of separate writes.
+
+    The default implementation simply calls `write_entry` for each entry.
+    Stores may override if they're capable of one-shot bulk writes, like
+    Redis `MSET`.
+
+    *Jeremy Daer*
+
+*   Add default option to module and class attribute accessors.
+
+        mattr_accessor :settings, default: {}
+
+    Works for `mattr_reader`, `mattr_writer`, `cattr_accessor`, `cattr_reader`,
+    and `cattr_writer` as well.
+
+    *Genadi Samokovarov*
+
+*   Add `Date#prev_occurring` and `Date#next_occurring` to return specified next/previous occurring day of week.
+
+    *Shota Iguchi*
+
+*   Add default option to `class_attribute`.
+
+    Before:
+
+        class_attribute :settings
+        self.settings = {}
+
+    Now:
+
+        class_attribute :settings, default: {}
+
+    *DHH*
+
+*   `#singularize` and `#pluralize` now respect uncountables for the specified locale.
+
+    *Eilis Hamilton*
+
+*   Add `ActiveSupport::CurrentAttributes` to provide a thread-isolated attributes singleton.
+    Primary use case is keeping all the per-request attributes easily available to the whole system.
+
+    *DHH*
+
+*   Fix implicit coercion calculations with scalars and durations
+
+    Previously calculations where the scalar is first would be converted to a duration
+    of seconds but this causes issues with dates being converted to times, e.g:
+
+        Time.zone = "Beijing"           # => Asia/Shanghai
+        date = Date.civil(2017, 5, 20)  # => Mon, 20 May 2017
+        2 * 1.day                       # => 172800 seconds
+        date + 2 * 1.day                # => Mon, 22 May 2017 00:00:00 CST +08:00
+
+    Now the `ActiveSupport::Duration::Scalar` calculation methods will try to maintain
+    the part structure of the duration where possible, e.g:
+
+        Time.zone = "Beijing"           # => Asia/Shanghai
+        date = Date.civil(2017, 5, 20)  # => Mon, 20 May 2017
+        2 * 1.day                       # => 2 days
+        date + 2 * 1.day                # => Mon, 22 May 2017
+
+    Fixes #29160, #28970.
+
+    *Andrew White*
+
+*   Add support for versioned cache entries. This enables the cache stores to recycle cache keys, greatly saving
+    on storage in cases with frequent churn. Works together with the separation of `#cache_key` and `#cache_version`
+    in Active Record and its use in Action Pack's fragment caching.
+
+    *DHH*
+
 *   Pass gem name and deprecation horizon to deprecation notifications.
 
     *Willem van Bergen*
diff --git a/activesupport/activesupport.gemspec b/activesupport/activesupport.gemspec
index 08370cba85..ed277c81ef 100644
--- a/activesupport/activesupport.gemspec
+++ b/activesupport/activesupport.gemspec
@@ -1,4 +1,4 @@
-version = File.read(File.expand_path("../../RAILS_VERSION", __FILE__)).strip
+version = File.read(File.expand_path("../RAILS_VERSION", __dir__)).strip
 
 Gem::Specification.new do |s|
   s.platform    = Gem::Platform::RUBY
diff --git a/activesupport/bin/generate_tables b/activesupport/bin/generate_tables
index aa36a01b5b..6f62593f14 100755
--- a/activesupport/bin/generate_tables
+++ b/activesupport/bin/generate_tables
@@ -1,7 +1,7 @@
 #!/usr/bin/env ruby
 
 begin
-  $:.unshift(File.expand_path(File.dirname(__FILE__) + "/../lib"))
+  $:.unshift(File.expand_path("../lib", __dir__))
   require "active_support"
 rescue IOError
 end
diff --git a/activesupport/bin/test b/activesupport/bin/test
index a7beb14b27..470ce93f10 100755
--- a/activesupport/bin/test
+++ b/activesupport/bin/test
@@ -1,4 +1,4 @@
 #!/usr/bin/env ruby
 
 COMPONENT_ROOT = File.expand_path("..", __dir__)
-require File.expand_path("../tools/test", COMPONENT_ROOT)
+require_relative "../../tools/test"
diff --git a/activesupport/lib/active_support.rb b/activesupport/lib/active_support.rb
index 03e3ce821a..a667fbb54a 100644
--- a/activesupport/lib/active_support.rb
+++ b/activesupport/lib/active_support.rb
@@ -32,6 +32,7 @@ module ActiveSupport
   extend ActiveSupport::Autoload
 
   autoload :Concern
+  autoload :CurrentAttributes
   autoload :Dependencies
   autoload :DescendantsTracker
   autoload :ExecutionWrapper
diff --git a/activesupport/lib/active_support/cache.rb b/activesupport/lib/active_support/cache.rb
index 4d8c2046e8..3847d8b7ae 100644
--- a/activesupport/lib/active_support/cache.rb
+++ b/activesupport/lib/active_support/cache.rb
@@ -88,10 +88,11 @@ module ActiveSupport
       private
         def retrieve_cache_key(key)
           case
-          when key.respond_to?(:cache_key) then key.cache_key
-          when key.is_a?(Array)            then key.map { |element| retrieve_cache_key(element) }.to_param
-          when key.respond_to?(:to_a)      then retrieve_cache_key(key.to_a)
-          else                                  key.to_param
+          when key.respond_to?(:cache_key_with_version) then key.cache_key_with_version
+          when key.respond_to?(:cache_key)              then key.cache_key
+          when key.is_a?(Array)                         then key.map { |element| retrieve_cache_key(element) }.to_param
+          when key.respond_to?(:to_a)                   then retrieve_cache_key(key.to_a)
+          else                                               key.to_param
           end.to_s
         end
 
@@ -219,6 +220,10 @@ module ActiveSupport
       #   cache = ActiveSupport::Cache::MemoryStore.new(expires_in: 5.minutes)
       #   cache.write(key, value, expires_in: 1.minute) # Set a lower value for one entry
       #
+      # Setting <tt>:version</tt> verifies the cache stored under <tt>name</tt>
+      # is of the same version. nil is returned on mismatches despite contents.
+      # This feature is used to support recyclable cache keys.
+      #
       # Setting <tt>:race_condition_ttl</tt> is very useful in situations where
       # a cache entry is used very frequently and is under heavy load. If a
       # cache expires and due to heavy load several different processes will try
@@ -287,6 +292,7 @@ module ActiveSupport
           instrument(:read, name, options) do |payload|
             cached_entry = read_entry(key, options) unless options[:force]
             entry = handle_expired_entry(cached_entry, key, options)
+            entry = nil if entry && entry.mismatched?(normalize_version(name, options))
             payload[:super_operation] = :fetch if payload
             payload[:hit] = !!entry if payload
           end
@@ -303,21 +309,30 @@ module ActiveSupport
         end
       end
 
-      # Fetches data from the cache, using the given key. If there is data in
+      # Reads data from the cache, using the given key. If there is data in
       # the cache with the given key, then that data is returned. Otherwise,
       # +nil+ is returned.
       #
+      # Note, if data was written with the <tt>:expires_in<tt> or <tt>:version</tt> options,
+      # both of these conditions are applied before the data is returned.
+      #
       # Options are passed to the underlying cache implementation.
       def read(name, options = nil)
         options = merged_options(options)
-        key = normalize_key(name, options)
+        key     = normalize_key(name, options)
+        version = normalize_version(name, options)
+
         instrument(:read, name, options) do |payload|
           entry = read_entry(key, options)
+
           if entry
             if entry.expired?
               delete_entry(key, options)
               payload[:hit] = false if payload
               nil
+            elsif entry.mismatched?(version)
+              payload[:hit] = false if payload
+              nil
             else
               payload[:hit] = true if payload
               entry.value
@@ -341,11 +356,15 @@ module ActiveSupport
 
         results = {}
         names.each do |name|
-          key = normalize_key(name, options)
-          entry = read_entry(key, options)
+          key     = normalize_key(name, options)
+          version = normalize_version(name, options)
+          entry   = read_entry(key, options)
+
           if entry
             if entry.expired?
               delete_entry(key, options)
+            elsif entry.mismatched?(version)
+              # Skip mismatched versions
             else
               results[name] = entry.value
             end
@@ -354,6 +373,19 @@ module ActiveSupport
         results
       end
 
+      # Cache Storage API to write multiple values at once.
+      def write_multi(hash, options = nil)
+        options = merged_options(options)
+
+        instrument :write_multi, hash, options do |payload|
+          entries = hash.each_with_object({}) do |(name, value), memo|
+            memo[normalize_key(name, options)] = Entry.new(value, options.merge(version: normalize_version(name, options)))
+          end
+
+          write_multi_entries entries, options
+        end
+      end
+
       # Fetches data from the cache, using the given keys. If there is data in
       # the cache with the given keys, then that data is returned. Otherwise,
       # the supplied block is called for each key for which there was no data,
@@ -378,14 +410,15 @@ module ActiveSupport
 
         options = names.extract_options!
         options = merged_options(options)
-        results = read_multi(*names, options)
 
-        names.each_with_object({}) do |name, memo|
-          memo[name] = results.fetch(name) do
-            value = yield name
-            write(name, value, options)
-            value
+        read_multi(*names, options).tap do |results|
+          writes = {}
+
+          (names - results.keys).each do |name|
+            results[name] = writes[name] = yield(name)
           end
+
+          write_multi writes, options
         end
       end
 
@@ -396,7 +429,7 @@ module ActiveSupport
         options = merged_options(options)
 
         instrument(:write, name, options) do
-          entry = Entry.new(value, options)
+          entry = Entry.new(value, options.merge(version: normalize_version(name, options)))
           write_entry(normalize_key(name, options), entry, options)
         end
       end
@@ -420,7 +453,7 @@ module ActiveSupport
 
         instrument(:exist?, name) do
           entry = read_entry(normalize_key(name, options), options)
-          (entry && !entry.expired?) || false
+          (entry && !entry.expired? && !entry.mismatched?(normalize_version(name, options))) || false
         end
       end
 
@@ -466,7 +499,7 @@ module ActiveSupport
       # The options hash is passed to the underlying cache implementation.
       #
       # All implementations may not support this method.
-      def clear
+      def clear(options = nil)
         raise NotImplementedError.new("#{self.class.name} does not support clear")
       end
 
@@ -502,6 +535,14 @@ module ActiveSupport
           raise NotImplementedError.new
         end
 
+        # Writes multiple entries to the cache implementation. Subclasses MAY
+        # implement this method.
+        def write_multi_entries(hash, options)
+          hash.each do |key, entry|
+            write_entry key, entry, options
+          end
+        end
+
         # Deletes an entry from the cache implementation. Subclasses must
         # implement this method.
         def delete_entry(key, options)
@@ -517,6 +558,16 @@ module ActiveSupport
           end
         end
 
+        # Prefixes a key with the namespace. Namespace and key will be delimited
+        # with a colon.
+        def normalize_key(key, options)
+          key = expanded_key(key)
+          namespace = options[:namespace] if options
+          prefix = namespace.is_a?(Proc) ? namespace.call : namespace
+          key = "#{prefix}:#{key}" if prefix
+          key
+        end
+
         # Expands key to be a consistent string value. Invokes +cache_key+ if
         # object responds to +cache_key+. Otherwise, +to_param+ method will be
         # called. If the key is a Hash, then keys will be sorted alphabetically.
@@ -537,14 +588,16 @@ module ActiveSupport
           key.to_param
         end
 
-        # Prefixes a key with the namespace. Namespace and key will be delimited
-        # with a colon.
-        def normalize_key(key, options)
-          key = expanded_key(key)
-          namespace = options[:namespace] if options
-          prefix = namespace.is_a?(Proc) ? namespace.call : namespace
-          key = "#{prefix}:#{key}" if prefix
-          key
+        def normalize_version(key, options = nil)
+          (options && options[:version].try(:to_param)) || expanded_version(key)
+        end
+
+        def expanded_version(key)
+          case
+          when key.respond_to?(:cache_version) then key.cache_version.to_param
+          when key.is_a?(Array)                then key.map { |element| expanded_version(element) }.compact.to_param
+          when key.respond_to?(:to_a)          then expanded_version(key.to_a)
+          end
         end
 
         def instrument(operation, key, options = nil)
@@ -591,13 +644,16 @@ module ActiveSupport
         end
     end
 
-    # This class is used to represent cache entries. Cache entries have a value and an optional
-    # expiration time. The expiration time is used to support the :race_condition_ttl option
-    # on the cache.
+    # This class is used to represent cache entries. Cache entries have a value, an optional
+    # expiration time, and an optional version. The expiration time is used to support the :race_condition_ttl option
+    # on the cache. The version is used to support the :version option on the cache for rejecting
+    # mismatches.
     #
     # Since cache entries in most instances will be serialized, the internals of this class are highly optimized
     # using short instance variable names that are lazily defined.
     class Entry # :nodoc:
+      attr_reader :version
+
       DEFAULT_COMPRESS_LIMIT = 16.kilobytes
 
       # Creates a new cache entry for the specified value. Options supported are
@@ -610,6 +666,7 @@ module ActiveSupport
           @value = value
         end
 
+        @version    = options[:version]
         @created_at = Time.now.to_f
         @expires_in = options[:expires_in]
         @expires_in = @expires_in.to_f if @expires_in
@@ -619,6 +676,10 @@ module ActiveSupport
         compressed? ? uncompress(@value) : @value
       end
 
+      def mismatched?(version)
+        @version && version && @version != version
+      end
+
       # Checks if the entry is expired. The +expires_in+ parameter can override
       # the value set when the entry was created.
       def expired?
diff --git a/activesupport/lib/active_support/cache/file_store.rb b/activesupport/lib/active_support/cache/file_store.rb
index d5c8585816..945f50a56e 100644
--- a/activesupport/lib/active_support/cache/file_store.rb
+++ b/activesupport/lib/active_support/cache/file_store.rb
@@ -27,7 +27,7 @@ module ActiveSupport
       # Deletes all items from the cache. In this case it deletes all the entries in the specified
       # file store directory except for .keep or .gitkeep. Be careful which directory is specified in your
       # config file when using +FileStore+ because everything in that directory will be deleted.
-      def clear
+      def clear(options = nil)
         root_dirs = exclude_from(cache_path, EXCLUDED_DIRS + GITKEEP_FILES)
         FileUtils.rm_r(root_dirs.collect { |f| File.join(cache_path, f) })
       rescue Errno::ENOENT
diff --git a/activesupport/lib/active_support/cache/mem_cache_store.rb b/activesupport/lib/active_support/cache/mem_cache_store.rb
index e09cee3335..06fa9f67ad 100644
--- a/activesupport/lib/active_support/cache/mem_cache_store.rb
+++ b/activesupport/lib/active_support/cache/mem_cache_store.rb
@@ -97,12 +97,18 @@ module ActiveSupport
         options = merged_options(options)
 
         keys_to_names = Hash[names.map { |name| [normalize_key(name, options), name] }]
+
         raw_values = @data.get_multi(keys_to_names.keys)
         values = {}
+
         raw_values.each do |key, value|
           entry = deserialize_entry(value)
-          values[keys_to_names[key]] = entry.value unless entry.expired?
+
+          unless entry.expired? || entry.mismatched?(normalize_version(keys_to_names[key], options))
+            values[keys_to_names[key]] = entry.value
+          end
         end
+
         values
       end
 
diff --git a/activesupport/lib/active_support/cache/strategy/local_cache.rb b/activesupport/lib/active_support/cache/strategy/local_cache.rb
index 91875a56f5..69b3a93a05 100644
--- a/activesupport/lib/active_support/cache/strategy/local_cache.rb
+++ b/activesupport/lib/active_support/cache/strategy/local_cache.rb
@@ -44,7 +44,7 @@ module ActiveSupport
             yield
           end
 
-          def clear
+          def clear(options = nil)
             @data.clear
           end
 
@@ -79,15 +79,15 @@ module ActiveSupport
             local_cache_key)
         end
 
-        def clear # :nodoc:
+        def clear(options = nil) # :nodoc:
           return super unless cache = local_cache
-          cache.clear
+          cache.clear(options)
           super
         end
 
         def cleanup(options = nil) # :nodoc:
           return super unless cache = local_cache
-          cache.clear(options)
+          cache.clear
           super
         end
 
diff --git a/activesupport/lib/active_support/callbacks.rb b/activesupport/lib/active_support/callbacks.rb
index d771cab68b..ddfa91a342 100644
--- a/activesupport/lib/active_support/callbacks.rb
+++ b/activesupport/lib/active_support/callbacks.rb
@@ -62,8 +62,7 @@ module ActiveSupport
 
     included do
       extend ActiveSupport::DescendantsTracker
-      class_attribute :__callbacks, instance_writer: false
-      self.__callbacks ||= {}
+      class_attribute :__callbacks, instance_writer: false, default: {}
     end
 
     CALLBACK_FILTER_TYPES = [:before, :after, :around]
diff --git a/activesupport/lib/active_support/core_ext.rb b/activesupport/lib/active_support/core_ext.rb
index f397f658f3..42e0acf66a 100644
--- a/activesupport/lib/active_support/core_ext.rb
+++ b/activesupport/lib/active_support/core_ext.rb
@@ -1,3 +1,3 @@
-(Dir["#{File.dirname(__FILE__)}/core_ext/*.rb"]).each do |path|
+Dir.glob(File.expand_path("core_ext/*.rb", __dir__)).each do |path|
   require path
 end
diff --git a/activesupport/lib/active_support/core_ext/class/attribute.rb b/activesupport/lib/active_support/core_ext/class/attribute.rb
index ba422f9071..8caddcd5c3 100644
--- a/activesupport/lib/active_support/core_ext/class/attribute.rb
+++ b/activesupport/lib/active_support/core_ext/class/attribute.rb
@@ -68,11 +68,16 @@ class Class
   #   object.setting = false  # => NoMethodError
   #
   # To opt out of both instance methods, pass <tt>instance_accessor: false</tt>.
+  #
+  # To set a default value for the attribute, pass <tt>default:</tt>, like so:
+  #
+  #   class_attribute :settings, default: {}
   def class_attribute(*attrs)
     options = attrs.extract_options!
-    instance_reader = options.fetch(:instance_accessor, true) && options.fetch(:instance_reader, true)
-    instance_writer = options.fetch(:instance_accessor, true) && options.fetch(:instance_writer, true)
+    instance_reader    = options.fetch(:instance_accessor, true) && options.fetch(:instance_reader, true)
+    instance_writer    = options.fetch(:instance_accessor, true) && options.fetch(:instance_writer, true)
     instance_predicate = options.fetch(:instance_predicate, true)
+    default_value      = options.fetch(:default, nil)
 
     attrs.each do |name|
       remove_possible_singleton_method(name)
@@ -123,6 +128,10 @@ class Class
         remove_possible_method "#{name}="
         attr_writer name
       end
+
+      unless default_value.nil?
+        self.send("#{name}=", default_value)
+      end
     end
   end
 end
diff --git a/activesupport/lib/active_support/core_ext/date_and_time/calculations.rb b/activesupport/lib/active_support/core_ext/date_and_time/calculations.rb
index f2ba7fdda5..e2e1d3e359 100644
--- a/activesupport/lib/active_support/core_ext/date_and_time/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/date_and_time/calculations.rb
@@ -320,6 +320,22 @@ module DateAndTime
       beginning_of_year..end_of_year
     end
 
+    # Returns specific next occurring day of week
+    def next_occurring(day_of_week)
+      current_day_number = wday != 0 ? wday - 1 : 6
+      from_now = DAYS_INTO_WEEK.fetch(day_of_week) - current_day_number
+      from_now += 7 unless from_now > 0
+      since(from_now.days)
+    end
+
+    # Returns specific previous occurring day of week
+    def prev_occurring(day_of_week)
+      current_day_number = wday != 0 ? wday - 1 : 6
+      ago = current_day_number - DAYS_INTO_WEEK.fetch(day_of_week)
+      ago += 7 unless ago > 0
+      ago(ago.days)
+    end
+
     private
       def first_hour(date_or_time)
         date_or_time.acts_like?(:time) ? date_or_time.beginning_of_day : date_or_time
diff --git a/activesupport/lib/active_support/core_ext/date_and_time/compatibility.rb b/activesupport/lib/active_support/core_ext/date_and_time/compatibility.rb
index ab80392460..2d45e16546 100644
--- a/activesupport/lib/active_support/core_ext/date_and_time/compatibility.rb
+++ b/activesupport/lib/active_support/core_ext/date_and_time/compatibility.rb
@@ -9,6 +9,6 @@ module DateAndTime
     # of the receiver. For backwards compatibility we're overriding
     # this behavior, but new apps will have an initializer that sets
     # this to true, because the new behavior is preferred.
-    mattr_accessor(:preserve_timezone, instance_writer: false) { false }
+    mattr_accessor :preserve_timezone, instance_writer: false, default: false
   end
 end
diff --git a/activesupport/lib/active_support/core_ext/module/attribute_accessors.rb b/activesupport/lib/active_support/core_ext/module/attribute_accessors.rb
index 2c24081eb9..9244cfa157 100644
--- a/activesupport/lib/active_support/core_ext/module/attribute_accessors.rb
+++ b/activesupport/lib/active_support/core_ext/module/attribute_accessors.rb
@@ -38,13 +38,10 @@ class Module
   #
   #   Person.new.hair_colors # => NoMethodError
   #
-  #
-  # Also, you can pass a block to set up the attribute with a default value.
+  # You can set a default value for the attribute.
   #
   #   module HairColors
-  #     mattr_reader :hair_colors do
-  #       [:brown, :black, :blonde, :red]
-  #     end
+  #     mattr_reader :hair_colors, default: [:brown, :black, :blonde, :red]
   #   end
   #
   #   class Person
@@ -52,8 +49,7 @@ class Module
   #   end
   #
   #   Person.new.hair_colors # => [:brown, :black, :blonde, :red]
-  def mattr_reader(*syms)
-    options = syms.extract_options!
+  def mattr_reader(*syms, instance_reader: true, instance_accessor: true, default: nil)
     syms.each do |sym|
       raise NameError.new("invalid attribute name: #{sym}") unless /\A[_A-Za-z]\w*\z/.match?(sym)
       class_eval(<<-EOS, __FILE__, __LINE__ + 1)
@@ -64,14 +60,16 @@ class Module
         end
       EOS
 
-      unless options[:instance_reader] == false || options[:instance_accessor] == false
+      if instance_reader && instance_accessor
         class_eval(<<-EOS, __FILE__, __LINE__ + 1)
           def #{sym}
             @@#{sym}
           end
         EOS
       end
-      class_variable_set("@@#{sym}", yield) if block_given?
+
+      sym_default_value = (block_given? && default.nil?) ? yield : default
+      class_variable_set("@@#{sym}", sym_default_value) unless sym_default_value.nil?
     end
   end
   alias :cattr_reader :mattr_reader
@@ -107,12 +105,10 @@ class Module
   #
   #   Person.new.hair_colors = [:blonde, :red] # => NoMethodError
   #
-  # Also, you can pass a block to set up the attribute with a default value.
+  # You can set a default value for the attribute.
   #
   #   module HairColors
-  #     mattr_writer :hair_colors do
-  #       [:brown, :black, :blonde, :red]
-  #     end
+  #     mattr_writer :hair_colors, default: [:brown, :black, :blonde, :red]
   #   end
   #
   #   class Person
@@ -120,8 +116,7 @@ class Module
   #   end
   #
   #   Person.class_variable_get("@@hair_colors") # => [:brown, :black, :blonde, :red]
-  def mattr_writer(*syms)
-    options = syms.extract_options!
+  def mattr_writer(*syms, instance_writer: true, instance_accessor: true, default: nil)
     syms.each do |sym|
       raise NameError.new("invalid attribute name: #{sym}") unless /\A[_A-Za-z]\w*\z/.match?(sym)
       class_eval(<<-EOS, __FILE__, __LINE__ + 1)
@@ -132,14 +127,16 @@ class Module
         end
       EOS
 
-      unless options[:instance_writer] == false || options[:instance_accessor] == false
+      if instance_writer && instance_accessor
         class_eval(<<-EOS, __FILE__, __LINE__ + 1)
           def #{sym}=(obj)
             @@#{sym} = obj
           end
         EOS
       end
-      send("#{sym}=", yield) if block_given?
+
+      sym_default_value = (block_given? && default.nil?) ? yield : default
+      send("#{sym}=", sym_default_value) unless sym_default_value.nil?
     end
   end
   alias :cattr_writer :mattr_writer
@@ -197,12 +194,10 @@ class Module
   #   Person.new.hair_colors = [:brown]  # => NoMethodError
   #   Person.new.hair_colors             # => NoMethodError
   #
-  # Also you can pass a block to set up the attribute with a default value.
+  # You can set a default value for the attribute.
   #
   #   module HairColors
-  #     mattr_accessor :hair_colors do
-  #       [:brown, :black, :blonde, :red]
-  #     end
+  #     mattr_accessor :hair_colors, default: [:brown, :black, :blonde, :red]
   #   end
   #
   #   class Person
@@ -210,9 +205,9 @@ class Module
   #   end
   #
   #   Person.class_variable_get("@@hair_colors") # => [:brown, :black, :blonde, :red]
-  def mattr_accessor(*syms, &blk)
-    mattr_reader(*syms, &blk)
-    mattr_writer(*syms)
+  def mattr_accessor(*syms, instance_reader: true, instance_writer: true, instance_accessor: true, default: nil, &blk)
+    mattr_reader(*syms, instance_reader: instance_reader, instance_accessor: instance_accessor, default: default, &blk)
+    mattr_writer(*syms, instance_writer: instance_writer, instance_accessor: instance_accessor, default: default)
   end
   alias :cattr_accessor :mattr_accessor
 end
diff --git a/activesupport/lib/active_support/current_attributes.rb b/activesupport/lib/active_support/current_attributes.rb
new file mode 100644
index 0000000000..872b0663c7
--- /dev/null
+++ b/activesupport/lib/active_support/current_attributes.rb
@@ -0,0 +1,193 @@
+module ActiveSupport
+  # Abstract super class that provides a thread-isolated attributes singleton, which resets automatically
+  # before and after each request. This allows you to keep all the per-request attributes easily
+  # available to the whole system.
+  #
+  # The following full app-like example demonstrates how to use a Current class to
+  # facilitate easy access to the global, per-request attributes without passing them deeply
+  # around everywhere:
+  #
+  #   # app/models/current.rb
+  #   class Current < ActiveSupport::CurrentAttributes
+  #     attribute :account, :user
+  #     attribute :request_id, :user_agent, :ip_address
+  #
+  #     resets { Time.zone = nil }
+  #
+  #     def user=(user)
+  #       super
+  #       self.account = user.account
+  #       Time.zone    = user.time_zone
+  #     end
+  #   end
+  #
+  #   # app/controllers/concerns/authentication.rb
+  #   module Authentication
+  #     extend ActiveSupport::Concern
+  #
+  #     included do
+  #       before_action :authenticate
+  #     end
+  #
+  #     private
+  #       def authenticate
+  #         if authenticated_user = User.find_by(id: cookies.signed[:user_id])
+  #           Current.user = authenticated_user
+  #         else
+  #           redirect_to new_session_url
+  #         end
+  #       end
+  #   end
+  #
+  #   # app/controllers/concerns/set_current_request_details.rb
+  #   module SetCurrentRequestDetails
+  #     extend ActiveSupport::Concern
+  #
+  #     included do
+  #       before_action do
+  #         Current.request_id = request.uuid
+  #         Current.user_agent = request.user_agent
+  #         Current.ip_address = request.ip
+  #       end
+  #     end
+  #   end
+  #
+  #   class ApplicationController < ActionController::Base
+  #     include Authentication
+  #     include SetCurrentRequestDetails
+  #   end
+  #
+  #   class MessagesController < ApplicationController
+  #     def create
+  #       Current.account.messages.create(message_params)
+  #     end
+  #   end
+  #
+  #   class Message < ApplicationRecord
+  #     belongs_to :creator, default: -> { Current.user }
+  #     after_create { |message| Event.create(record: message) }
+  #   end
+  #
+  #   class Event < ApplicationRecord
+  #     before_create do
+  #       self.request_id = Current.request_id
+  #       self.user_agent = Current.user_agent
+  #       self.ip_address = Current.ip_address
+  #     end
+  #   end
+  #
+  # A word of caution: It's easy to overdo a global singleton like Current and tangle your model as a result.
+  # Current should only be used for a few, top-level globals, like account, user, and request details.
+  # The attributes stuck in Current should be used by more or less all actions on all requests. If you start
+  # sticking controller-specific attributes in there, you're going to create a mess.
+  class CurrentAttributes
+    include ActiveSupport::Callbacks
+    define_callbacks :reset
+
+    class << self
+      # Returns singleton instance for this class in this thread. If none exists, one is created.
+      def instance
+        current_instances[name] ||= new
+      end
+
+      # Declares one or more attributes that will be given both class and instance accessor methods.
+      def attribute(*names)
+        generated_attribute_methods.module_eval do
+          names.each do |name|
+            define_method(name) do
+              attributes[name.to_sym]
+            end
+
+            define_method("#{name}=") do |attribute|
+              attributes[name.to_sym] = attribute
+            end
+          end
+        end
+
+        names.each do |name|
+          define_singleton_method(name) do
+            instance.public_send(name)
+          end
+
+          define_singleton_method("#{name}=") do |attribute|
+            instance.public_send("#{name}=", attribute)
+          end
+        end
+      end
+
+      # Calls this block after #reset is called on the instance. Used for resetting external collaborators, like Time.zone.
+      def resets(&block)
+        set_callback :reset, :after, &block
+      end
+
+      delegate :set, :reset, to: :instance
+
+      def reset_all # :nodoc:
+        current_instances.each_value(&:reset)
+      end
+
+      def clear_all # :nodoc:
+        reset_all
+        current_instances.clear
+      end
+
+      private
+        def generated_attribute_methods
+          @generated_attribute_methods ||= Module.new.tap { |mod| include mod }
+        end
+
+        def current_instances
+          Thread.current[:current_attributes_instances] ||= {}
+        end
+
+        def method_missing(name, *args, &block)
+          # Caches the method definition as a singleton method of the receiver.
+          #
+          # By letting #delegate handle it, we avoid an enclosure that'll capture args.
+          singleton_class.delegate name, to: :instance
+
+          send(name, *args, &block)
+        end
+    end
+
+    attr_accessor :attributes
+
+    def initialize
+      @attributes = {}
+    end
+
+    # Expose one or more attributes within a block. Old values are returned after the block concludes.
+    # Example demonstrating the common use of needing to set Current attributes outside the request-cycle:
+    #
+    #   class Chat::PublicationJob < ApplicationJob
+    #     def perform(attributes, room_number, creator)
+    #       Current.set(person: creator) do
+    #         Chat::Publisher.publish(attributes: attributes, room_number: room_number)
+    #       end
+    #     end
+    #   end
+    def set(set_attributes)
+      old_attributes = compute_attributes(set_attributes.keys)
+      assign_attributes(set_attributes)
+      yield
+    ensure
+      assign_attributes(old_attributes)
+    end
+
+    # Reset all attributes. Should be called before and after actions, when used as a per-request singleton.
+    def reset
+      run_callbacks :reset do
+        self.attributes = {}
+      end
+    end
+
+    private
+      def assign_attributes(new_attributes)
+        new_attributes.each { |key, value| public_send("#{key}=", value) }
+      end
+
+      def compute_attributes(keys)
+        keys.collect { |key| [ key, public_send(key) ] }.to_h
+      end
+  end
+end
diff --git a/activesupport/lib/active_support/dependencies.rb b/activesupport/lib/active_support/dependencies.rb
index e125b657f2..3cd8f3d0ac 100644
--- a/activesupport/lib/active_support/dependencies.rb
+++ b/activesupport/lib/active_support/dependencies.rb
@@ -18,8 +18,7 @@ module ActiveSupport #:nodoc:
   module Dependencies #:nodoc:
     extend self
 
-    mattr_accessor :interlock
-    self.interlock = Interlock.new
+    mattr_accessor :interlock, default: Interlock.new
 
     # :doc:
 
@@ -46,46 +45,37 @@ module ActiveSupport #:nodoc:
     # :nodoc:
 
     # Should we turn on Ruby warnings on the first load of dependent files?
-    mattr_accessor :warnings_on_first_load
-    self.warnings_on_first_load = false
+    mattr_accessor :warnings_on_first_load, default: false
 
     # All files ever loaded.
-    mattr_accessor :history
-    self.history = Set.new
+    mattr_accessor :history, default: Set.new
 
     # All files currently loaded.
-    mattr_accessor :loaded
-    self.loaded = Set.new
+    mattr_accessor :loaded, default: Set.new
 
     # Stack of files being loaded.
-    mattr_accessor :loading
-    self.loading = []
+    mattr_accessor :loading, default: []
 
     # Should we load files or require them?
-    mattr_accessor :mechanism
-    self.mechanism = ENV["NO_RELOAD"] ? :require : :load
+    mattr_accessor :mechanism, default: ENV["NO_RELOAD"] ? :require : :load
 
     # The set of directories from which we may automatically load files. Files
     # under these directories will be reloaded on each request in development mode,
     # unless the directory also appears in autoload_once_paths.
-    mattr_accessor :autoload_paths
-    self.autoload_paths = []
+    mattr_accessor :autoload_paths, default: []
 
     # The set of directories from which automatically loaded constants are loaded
     # only once. All directories in this set must also be present in +autoload_paths+.
-    mattr_accessor :autoload_once_paths
-    self.autoload_once_paths = []
+    mattr_accessor :autoload_once_paths, default: []
 
     # An array of qualified constant names that have been loaded. Adding a name
     # to this array will cause it to be unloaded the next time Dependencies are
     # cleared.
-    mattr_accessor :autoloaded_constants
-    self.autoloaded_constants = []
+    mattr_accessor :autoloaded_constants, default: []
 
     # 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
-    self.explicitly_unloadable_constants = []
+    mattr_accessor :explicitly_unloadable_constants, default: []
 
     # 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
@@ -175,8 +165,7 @@ module ActiveSupport #:nodoc:
     end
 
     # An internal stack used to record which constants are loaded by any block.
-    mattr_accessor :constant_watch_stack
-    self.constant_watch_stack = WatchStack.new
+    mattr_accessor :constant_watch_stack, default: WatchStack.new
 
     # Module includes this module.
     module ModuleConstMissing #:nodoc:
diff --git a/activesupport/lib/active_support/deprecation/reporting.rb b/activesupport/lib/active_support/deprecation/reporting.rb
index 851d8eeda1..140bdccbb3 100644
--- a/activesupport/lib/active_support/deprecation/reporting.rb
+++ b/activesupport/lib/active_support/deprecation/reporting.rb
@@ -102,7 +102,7 @@ module ActiveSupport
           end
         end
 
-        RAILS_GEM_ROOT = File.expand_path("../../../../..", __FILE__) + "/"
+        RAILS_GEM_ROOT = File.expand_path("../../../..", __dir__)
 
         def ignored_callstack(path)
           path.start_with?(RAILS_GEM_ROOT) || path.start_with?(RbConfig::CONFIG["rubylibdir"])
diff --git a/activesupport/lib/active_support/duration.rb b/activesupport/lib/active_support/duration.rb
index d4424ed792..39deb2313f 100644
--- a/activesupport/lib/active_support/duration.rb
+++ b/activesupport/lib/active_support/duration.rb
@@ -37,27 +37,56 @@ module ActiveSupport
       end
 
       def +(other)
-        calculate(:+, other)
+        if Duration === other
+          seconds   = value + other.parts[:seconds]
+          new_parts = other.parts.merge(seconds: seconds)
+          new_value = value + other.value
+
+          Duration.new(new_value, new_parts)
+        else
+          calculate(:+, other)
+        end
       end
 
       def -(other)
-        calculate(:-, other)
+        if Duration === other
+          seconds   = value - other.parts[:seconds]
+          new_parts = other.parts.map { |part, other_value| [part, -other_value] }.to_h
+          new_parts = new_parts.merge(seconds: seconds)
+          new_value = value - other.value
+
+          Duration.new(new_value, new_parts)
+        else
+          calculate(:-, other)
+        end
       end
 
       def *(other)
-        calculate(:*, other)
+        if Duration === other
+          new_parts = other.parts.map { |part, other_value| [part, value * other_value] }.to_h
+          new_value = value * other.value
+
+          Duration.new(new_value, new_parts)
+        else
+          calculate(:*, other)
+        end
       end
 
       def /(other)
-        calculate(:/, other)
+        if Duration === other
+          new_parts = other.parts.map { |part, other_value| [part, value / other_value] }.to_h
+          new_value = new_parts.inject(0) { |total, (part, value)| total + value * Duration::PARTS_IN_SECONDS[part] }
+
+          Duration.new(new_value, new_parts)
+        else
+          calculate(:/, other)
+        end
       end
 
       private
         def calculate(op, other)
           if Scalar === other
             Scalar.new(value.public_send(op, other.value))
-          elsif Duration === other
-            Duration.seconds(value).public_send(op, other)
           elsif Numeric === other
             Scalar.new(value.public_send(op, other))
           else
diff --git a/activesupport/lib/active_support/i18n.rb b/activesupport/lib/active_support/i18n.rb
index f0408f429c..1a1f1a1257 100644
--- a/activesupport/lib/active_support/i18n.rb
+++ b/activesupport/lib/active_support/i18n.rb
@@ -10,4 +10,4 @@ end
 require "active_support/lazy_load_hooks"
 
 ActiveSupport.run_load_hooks(:i18n)
-I18n.load_path << "#{File.dirname(__FILE__)}/locale/en.yml"
+I18n.load_path << File.expand_path("locale/en.yml", __dir__)
diff --git a/activesupport/lib/active_support/i18n_railtie.rb b/activesupport/lib/active_support/i18n_railtie.rb
index f05c707ccd..51fe6f3418 100644
--- a/activesupport/lib/active_support/i18n_railtie.rb
+++ b/activesupport/lib/active_support/i18n_railtie.rb
@@ -66,10 +66,6 @@ module I18n
       app.reloaders << reloader
       app.reloader.to_run do
         reloader.execute_if_updated { require_unload_lock! }
-        # TODO: remove the following line as soon as the return value of
-        # callbacks is ignored, that is, returning `false` does not
-        # display a deprecation warning or halts the callback chain.
-        true
       end
       reloader.execute
 
diff --git a/activesupport/lib/active_support/inflector/methods.rb b/activesupport/lib/active_support/inflector/methods.rb
index 1b089a7538..ff1a0cb8c7 100644
--- a/activesupport/lib/active_support/inflector/methods.rb
+++ b/activesupport/lib/active_support/inflector/methods.rb
@@ -28,7 +28,7 @@ module ActiveSupport
     #   pluralize('CamelOctopus')     # => "CamelOctopi"
     #   pluralize('ley', :es)         # => "leyes"
     def pluralize(word, locale = :en)
-      apply_inflections(word, inflections(locale).plurals)
+      apply_inflections(word, inflections(locale).plurals, locale)
     end
 
     # The reverse of #pluralize, returns the singular form of a word in a
@@ -45,7 +45,7 @@ module ActiveSupport
     #   singularize('CamelOctopi')      # => "CamelOctopus"
     #   singularize('leyes', :es)       # => "ley"
     def singularize(word, locale = :en)
-      apply_inflections(word, inflections(locale).singulars)
+      apply_inflections(word, inflections(locale).singulars, locale)
     end
 
     # Converts strings to UpperCamelCase.
@@ -387,12 +387,15 @@ module ActiveSupport
 
       # Applies inflection rules for +singularize+ and +pluralize+.
       #
-      #  apply_inflections('post', inflections.plurals)    # => "posts"
-      #  apply_inflections('posts', inflections.singulars) # => "post"
-      def apply_inflections(word, rules)
+      # If passed an optional +locale+ parameter, the uncountables will be
+      # found for that locale.
+      #
+      #  apply_inflections('post', inflections.plurals, :en)    # => "posts"
+      #  apply_inflections('posts', inflections.singulars, :en) # => "post"
+      def apply_inflections(word, rules, locale = :en)
         result = word.to_s.dup
 
-        if word.empty? || inflections.uncountables.uncountable?(result)
+        if word.empty? || inflections(locale).uncountables.uncountable?(result)
           result
         else
           rules.each { |(rule, replacement)| break if result.sub!(rule, replacement) }
diff --git a/activesupport/lib/active_support/log_subscriber.rb b/activesupport/lib/active_support/log_subscriber.rb
index e2c4f33565..a05758d6aa 100644
--- a/activesupport/lib/active_support/log_subscriber.rb
+++ b/activesupport/lib/active_support/log_subscriber.rb
@@ -49,8 +49,7 @@ module ActiveSupport
     CYAN    = "\e[36m"
     WHITE   = "\e[37m"
 
-    mattr_accessor :colorize_logging
-    self.colorize_logging = true
+    mattr_accessor :colorize_logging, default: true
 
     class << self
       def logger
@@ -81,8 +80,10 @@ module ActiveSupport
 
     def finish(name, id, payload)
       super if logger
-    rescue Exception => e
-      logger.error "Could not log #{name.inspect} event. #{e.class}: #{e.message} #{e.backtrace}"
+    rescue => e
+      if logger
+        logger.error "Could not log #{name.inspect} event. #{e.class}: #{e.message} #{e.backtrace}"
+      end
     end
 
   private
diff --git a/activesupport/lib/active_support/logger_silence.rb b/activesupport/lib/active_support/logger_silence.rb
index 632994cf50..9c64afaaca 100644
--- a/activesupport/lib/active_support/logger_silence.rb
+++ b/activesupport/lib/active_support/logger_silence.rb
@@ -6,8 +6,7 @@ module LoggerSilence
   extend ActiveSupport::Concern
 
   included do
-    cattr_accessor :silencer
-    self.silencer = true
+    cattr_accessor :silencer, default: true
   end
 
   # Silences the logger for the duration of the block.
diff --git a/activesupport/lib/active_support/message_encryptor.rb b/activesupport/lib/active_support/message_encryptor.rb
index 726e1464ad..e576766c64 100644
--- a/activesupport/lib/active_support/message_encryptor.rb
+++ b/activesupport/lib/active_support/message_encryptor.rb
@@ -19,7 +19,17 @@ module ActiveSupport
   #   encrypted_data = crypt.encrypt_and_sign('my secret data')                  # => "NlFBTTMwOUV5UlA1QlNEN2xkY2d6eThYWWh..."
   #   crypt.decrypt_and_verify(encrypted_data)                                   # => "my secret data"
   class MessageEncryptor
-    DEFAULT_CIPHER = "aes-256-cbc"
+    class << self
+      attr_accessor :use_authenticated_message_encryption #:nodoc:
+
+      def default_cipher #:nodoc:
+        if use_authenticated_message_encryption
+          "aes-256-gcm"
+        else
+          "aes-256-cbc"
+        end
+      end
+    end
 
     module NullSerializer #:nodoc:
       def self.load(value)
@@ -45,7 +55,7 @@ module ActiveSupport
     OpenSSLCipherError = OpenSSL::Cipher::CipherError
 
     # Initialize a new MessageEncryptor. +secret+ must be at least as long as
-    # the cipher key size. For the default 'aes-256-cbc' cipher, this is 256
+    # the cipher key size. For the default 'aes-256-gcm' cipher, this is 256
     # bits. If you are using a user-entered secret, you can generate a suitable
     # key by using <tt>ActiveSupport::KeyGenerator</tt> or a similar key
     # derivation function.
@@ -57,7 +67,7 @@ module ActiveSupport
     #
     # Options:
     # * <tt>:cipher</tt>     - Cipher to use. Can be any cipher returned by
-    #   <tt>OpenSSL::Cipher.ciphers</tt>. Default is 'aes-256-cbc'.
+    #   <tt>OpenSSL::Cipher.ciphers</tt>. Default is 'aes-256-gcm'.
     # * <tt>:digest</tt> - String of digest to use for signing. Default is
     #   +SHA1+. Ignored when using an AEAD cipher like 'aes-256-gcm'.
     # * <tt>:serializer</tt> - Object serializer to use. Default is +Marshal+.
@@ -66,7 +76,7 @@ module ActiveSupport
       sign_secret = signature_key_or_options.first
       @secret = secret
       @sign_secret = sign_secret
-      @cipher = options[:cipher] || DEFAULT_CIPHER
+      @cipher = options[:cipher] || self.class.default_cipher
       @digest = options[:digest] || "SHA1" unless aead_mode?
       @verifier = resolve_verifier
       @serializer = options[:serializer] || Marshal
@@ -85,7 +95,7 @@ module ActiveSupport
     end
 
     # Given a cipher, returns the key length of the cipher to help generate the key of desired size
-    def self.key_len(cipher = DEFAULT_CIPHER)
+    def self.key_len(cipher = default_cipher)
       OpenSSL::Cipher.new(cipher).key_len
     end
 
diff --git a/activesupport/lib/active_support/multibyte/unicode.rb b/activesupport/lib/active_support/multibyte/unicode.rb
index 0912912aba..8223e45e5a 100644
--- a/activesupport/lib/active_support/multibyte/unicode.rb
+++ b/activesupport/lib/active_support/multibyte/unicode.rb
@@ -357,7 +357,7 @@ module ActiveSupport
 
         # Returns the directory in which the data files are stored.
         def self.dirname
-          File.dirname(__FILE__) + "/../values/"
+          File.expand_path("../values", __dir__)
         end
 
         # Returns the filename for the data file for this version.
diff --git a/activesupport/lib/active_support/number_helper.rb b/activesupport/lib/active_support/number_helper.rb
index 880340ca86..9cb2821cb6 100644
--- a/activesupport/lib/active_support/number_helper.rb
+++ b/activesupport/lib/active_support/number_helper.rb
@@ -4,6 +4,7 @@ module ActiveSupport
 
     eager_autoload do
       autoload :NumberConverter
+      autoload :RoundingHelper
       autoload :NumberToRoundedConverter
       autoload :NumberToDelimitedConverter
       autoload :NumberToHumanConverter
diff --git a/activesupport/lib/active_support/number_helper/number_to_human_converter.rb b/activesupport/lib/active_support/number_helper/number_to_human_converter.rb
index 56185ddf4b..040343b5dd 100644
--- a/activesupport/lib/active_support/number_helper/number_to_human_converter.rb
+++ b/activesupport/lib/active_support/number_helper/number_to_human_converter.rb
@@ -9,6 +9,7 @@ module ActiveSupport
       self.validate_float = true
 
       def convert # :nodoc:
+        @number = RoundingHelper.new(options).round(number)
         @number = Float(number)
 
         # for backwards compatibility with those that didn't add strip_insignificant_zeros to their locale files
@@ -20,10 +21,7 @@ module ActiveSupport
         exponent = calculate_exponent(units)
         @number = number / (10**exponent)
 
-        until (rounded_number = NumberToRoundedConverter.convert(number, options)) != NumberToRoundedConverter.convert(1000, options)
-          @number = number / 1000.0
-          exponent += 3
-        end
+        rounded_number = NumberToRoundedConverter.convert(number, options)
         unit = determine_unit(units, exponent)
         format.gsub("%n".freeze, rounded_number).gsub("%u".freeze, unit).strip
       end
diff --git a/activesupport/lib/active_support/number_helper/number_to_rounded_converter.rb b/activesupport/lib/active_support/number_helper/number_to_rounded_converter.rb
index 1f013990ea..c32d85a45f 100644
--- a/activesupport/lib/active_support/number_helper/number_to_rounded_converter.rb
+++ b/activesupport/lib/active_support/number_helper/number_to_rounded_converter.rb
@@ -5,26 +5,14 @@ module ActiveSupport
       self.validate_float = true
 
       def convert
-        precision = options.delete :precision
+        helper = RoundingHelper.new(options)
+        rounded_number = helper.round(number)
 
-        if precision
-          case number
-          when Float, String
-            @number = BigDecimal(number.to_s)
-          when Rational
-            @number = BigDecimal(number, digit_count(number.to_i) + precision)
-          else
-            @number = number.to_d
-          end
-
-          if options.delete(:significant) && precision > 0
-            digits, rounded_number = digits_and_rounded_number(precision)
+        if precision = options[:precision]
+          if options[:significant] && precision > 0
+            digits = helper.digit_count(rounded_number)
             precision -= digits
             precision = 0 if precision < 0 # don't let it be negative
-          else
-            rounded_number = number.round(precision)
-            rounded_number = rounded_number.to_i if precision == 0 && rounded_number.finite?
-            rounded_number = rounded_number.abs if rounded_number.zero? # prevent showing negative zeros
           end
 
           formatted_string =
@@ -38,7 +26,7 @@ module ActiveSupport
               "%00.#{precision}f" % rounded_number
             end
         else
-          formatted_string = number
+          formatted_string = rounded_number
         end
 
         delimited_number = NumberToDelimitedConverter.convert(formatted_string, options)
@@ -79,14 +67,6 @@ module ActiveSupport
             number
           end
         end
-
-        def absolute_number(number)
-          number.respond_to?(:abs) ? number.abs : number.to_d.abs
-        end
-
-        def zero?
-          number.respond_to?(:zero?) ? number.zero? : number.to_d.zero?
-        end
     end
   end
 end
diff --git a/activesupport/lib/active_support/number_helper/rounding_helper.rb b/activesupport/lib/active_support/number_helper/rounding_helper.rb
new file mode 100644
index 0000000000..63b48444a6
--- /dev/null
+++ b/activesupport/lib/active_support/number_helper/rounding_helper.rb
@@ -0,0 +1,64 @@
+module ActiveSupport
+  module NumberHelper
+    class RoundingHelper # :nodoc:
+      attr_reader :options
+
+      def initialize(options)
+        @options = options
+      end
+
+      def round(number)
+        return number unless precision
+        number = convert_to_decimal(number)
+        if significant && precision > 0
+          round_significant(number)
+        else
+          round_without_significant(number)
+        end
+      end
+
+      def digit_count(number)
+        return 1 if number.zero?
+        (Math.log10(absolute_number(number)) + 1).floor
+      end
+
+      private
+        def round_without_significant(number)
+          number = number.round(precision)
+          number = number.to_i if precision == 0 && number.finite?
+          number = number.abs if number.zero? # prevent showing negative zeros
+          number
+        end
+
+        def round_significant(number)
+          return 0 if number.zero?
+          digits = digit_count(number)
+          multiplier = 10**(digits - precision)
+          (number / BigDecimal.new(multiplier.to_f.to_s)).round * multiplier
+        end
+
+        def convert_to_decimal(number)
+          case number
+          when Float, String
+            BigDecimal(number.to_s)
+          when Rational
+            BigDecimal(number, digit_count(number.to_i) + precision)
+          else
+            number.to_d
+          end
+        end
+
+        def precision
+          options[:precision]
+        end
+
+        def significant
+          options[:significant]
+        end
+
+        def absolute_number(number)
+          number.respond_to?(:abs) ? number.abs : number.to_d.abs
+        end
+    end
+  end
+end
diff --git a/activesupport/lib/active_support/railtie.rb b/activesupport/lib/active_support/railtie.rb
index b875875afe..45bc51311b 100644
--- a/activesupport/lib/active_support/railtie.rb
+++ b/activesupport/lib/active_support/railtie.rb
@@ -7,6 +7,19 @@ module ActiveSupport
 
     config.eager_load_namespaces << ActiveSupport
 
+    initializer "active_support.set_authenticated_message_encryption" do |app|
+      if app.config.active_support.respond_to?(:use_authenticated_message_encryption)
+        ActiveSupport::MessageEncryptor.use_authenticated_message_encryption =
+          app.config.active_support.use_authenticated_message_encryption
+      end
+    end
+
+    initializer "active_support.reset_all_current_attributes_instances" do |app|
+      app.reloader.before_class_unload { ActiveSupport::CurrentAttributes.clear_all }
+      app.executor.to_run              { ActiveSupport::CurrentAttributes.reset_all }
+      app.executor.to_complete         { ActiveSupport::CurrentAttributes.reset_all }
+    end
+
     initializer "active_support.deprecation_behavior" do |app|
       if deprecation = app.config.active_support.deprecation
         ActiveSupport::Deprecation.behavior = deprecation
@@ -22,14 +35,7 @@ module ActiveSupport
         raise e.exception "tzinfo-data is not present. Please add gem 'tzinfo-data' to your Gemfile and run bundle install"
       end
       require "active_support/core_ext/time/zones"
-      zone_default = Time.find_zone!(app.config.time_zone)
-
-      unless zone_default
-        raise "Value assigned to config.time_zone not recognized. " \
-          'Run "rake time:zones:all" for a time zone names list.'
-      end
-
-      Time.zone_default = zone_default
+      Time.zone_default = Time.find_zone!(app.config.time_zone)
     end
 
     # Sets the default week start
diff --git a/activesupport/lib/active_support/reloader.rb b/activesupport/lib/active_support/reloader.rb
index 121c621751..9558146201 100644
--- a/activesupport/lib/active_support/reloader.rb
+++ b/activesupport/lib/active_support/reloader.rb
@@ -69,11 +69,8 @@ module ActiveSupport
       end
     end
 
-    class_attribute :executor
-    class_attribute :check
-
-    self.executor = Executor
-    self.check = lambda { false }
+    class_attribute :executor, default: Executor
+    class_attribute :check, default: lambda { false }
 
     def self.check! # :nodoc:
       @should_reload ||= check.call
diff --git a/activesupport/lib/active_support/rescuable.rb b/activesupport/lib/active_support/rescuable.rb
index 12ec8bf1b8..826832ba7d 100644
--- a/activesupport/lib/active_support/rescuable.rb
+++ b/activesupport/lib/active_support/rescuable.rb
@@ -8,8 +8,7 @@ module ActiveSupport
     extend Concern
 
     included do
-      class_attribute :rescue_handlers
-      self.rescue_handlers = []
+      class_attribute :rescue_handlers, default: []
     end
 
     module ClassMethods
diff --git a/activesupport/lib/active_support/testing/assertions.rb b/activesupport/lib/active_support/testing/assertions.rb
index 28cf2953bf..28e1df8870 100644
--- a/activesupport/lib/active_support/testing/assertions.rb
+++ b/activesupport/lib/active_support/testing/assertions.rb
@@ -167,7 +167,7 @@ module ActiveSupport
         retval
       end
 
-      # Assertion that the result of evaluating an expression is changed before
+      # Assertion that the result of evaluating an expression is not changed before
       # and after invoking the passed in block.
       #
       #   assert_no_changes 'Status.all_good?' do
diff --git a/activesupport/test/cache/behaviors.rb b/activesupport/test/cache/behaviors.rb
new file mode 100644
index 0000000000..efd045ac5e
--- /dev/null
+++ b/activesupport/test/cache/behaviors.rb
@@ -0,0 +1,7 @@
+require_relative "behaviors/autoloading_cache_behavior"
+require_relative "behaviors/cache_delete_matched_behavior"
+require_relative "behaviors/cache_increment_decrement_behavior"
+require_relative "behaviors/cache_store_behavior"
+require_relative "behaviors/cache_store_version_behavior"
+require_relative "behaviors/encoded_key_cache_behavior"
+require_relative "behaviors/local_cache_behavior"
diff --git a/activesupport/test/cache/behaviors/autoloading_cache_behavior.rb b/activesupport/test/cache/behaviors/autoloading_cache_behavior.rb
new file mode 100644
index 0000000000..5f8af331f6
--- /dev/null
+++ b/activesupport/test/cache/behaviors/autoloading_cache_behavior.rb
@@ -0,0 +1,41 @@
+require "dependencies_test_helpers"
+
+module AutoloadingCacheBehavior
+  include DependenciesTestHelpers
+
+  def test_simple_autoloading
+    with_autoloading_fixtures do
+      @cache.write("foo", EM.new)
+    end
+
+    remove_constants(:EM)
+    ActiveSupport::Dependencies.clear
+
+    with_autoloading_fixtures do
+      assert_kind_of EM, @cache.read("foo")
+    end
+
+    remove_constants(:EM)
+    ActiveSupport::Dependencies.clear
+  end
+
+  def test_two_classes_autoloading
+    with_autoloading_fixtures do
+      @cache.write("foo", [EM.new, ClassFolder.new])
+    end
+
+    remove_constants(:EM, :ClassFolder)
+    ActiveSupport::Dependencies.clear
+
+    with_autoloading_fixtures do
+      loaded = @cache.read("foo")
+      assert_kind_of Array, loaded
+      assert_equal 2, loaded.size
+      assert_kind_of EM, loaded[0]
+      assert_kind_of ClassFolder, loaded[1]
+    end
+
+    remove_constants(:EM, :ClassFolder)
+    ActiveSupport::Dependencies.clear
+  end
+end
diff --git a/activesupport/test/cache/behaviors/cache_delete_matched_behavior.rb b/activesupport/test/cache/behaviors/cache_delete_matched_behavior.rb
new file mode 100644
index 0000000000..b872eb0279
--- /dev/null
+++ b/activesupport/test/cache/behaviors/cache_delete_matched_behavior.rb
@@ -0,0 +1,13 @@
+module CacheDeleteMatchedBehavior
+  def test_delete_matched
+    @cache.write("foo", "bar")
+    @cache.write("fu", "baz")
+    @cache.write("foo/bar", "baz")
+    @cache.write("fu/baz", "bar")
+    @cache.delete_matched(/oo/)
+    assert !@cache.exist?("foo")
+    assert @cache.exist?("fu")
+    assert !@cache.exist?("foo/bar")
+    assert @cache.exist?("fu/baz")
+  end
+end
diff --git a/activesupport/test/cache/behaviors/cache_increment_decrement_behavior.rb b/activesupport/test/cache/behaviors/cache_increment_decrement_behavior.rb
new file mode 100644
index 0000000000..0d32339565
--- /dev/null
+++ b/activesupport/test/cache/behaviors/cache_increment_decrement_behavior.rb
@@ -0,0 +1,21 @@
+module CacheIncrementDecrementBehavior
+  def test_increment
+    @cache.write("foo", 1, raw: true)
+    assert_equal 1, @cache.read("foo").to_i
+    assert_equal 2, @cache.increment("foo")
+    assert_equal 2, @cache.read("foo").to_i
+    assert_equal 3, @cache.increment("foo")
+    assert_equal 3, @cache.read("foo").to_i
+    assert_nil @cache.increment("bar")
+  end
+
+  def test_decrement
+    @cache.write("foo", 3, raw: true)
+    assert_equal 3, @cache.read("foo").to_i
+    assert_equal 2, @cache.decrement("foo")
+    assert_equal 2, @cache.read("foo").to_i
+    assert_equal 1, @cache.decrement("foo")
+    assert_equal 1, @cache.read("foo").to_i
+    assert_nil @cache.decrement("bar")
+  end
+end
diff --git a/activesupport/test/cache/behaviors/cache_store_behavior.rb b/activesupport/test/cache/behaviors/cache_store_behavior.rb
new file mode 100644
index 0000000000..03c366e164
--- /dev/null
+++ b/activesupport/test/cache/behaviors/cache_store_behavior.rb
@@ -0,0 +1,329 @@
+# Tests the base functionality that should be identical across all cache stores.
+module CacheStoreBehavior
+  def test_should_read_and_write_strings
+    assert @cache.write("foo", "bar")
+    assert_equal "bar", @cache.read("foo")
+  end
+
+  def test_should_overwrite
+    @cache.write("foo", "bar")
+    @cache.write("foo", "baz")
+    assert_equal "baz", @cache.read("foo")
+  end
+
+  def test_fetch_without_cache_miss
+    @cache.write("foo", "bar")
+    assert_not_called(@cache, :write) do
+      assert_equal "bar", @cache.fetch("foo") { "baz" }
+    end
+  end
+
+  def test_fetch_with_cache_miss
+    assert_called_with(@cache, :write, ["foo", "baz", @cache.options]) do
+      assert_equal "baz", @cache.fetch("foo") { "baz" }
+    end
+  end
+
+  def test_fetch_with_cache_miss_passes_key_to_block
+    cache_miss = false
+    assert_equal 3, @cache.fetch("foo") { |key| cache_miss = true; key.length }
+    assert cache_miss
+
+    cache_miss = false
+    assert_equal 3, @cache.fetch("foo") { |key| cache_miss = true; key.length }
+    assert !cache_miss
+  end
+
+  def test_fetch_with_forced_cache_miss
+    @cache.write("foo", "bar")
+    assert_not_called(@cache, :read) do
+      assert_called_with(@cache, :write, ["foo", "bar", @cache.options.merge(force: true)]) do
+        @cache.fetch("foo", force: true) { "bar" }
+      end
+    end
+  end
+
+  def test_fetch_with_cached_nil
+    @cache.write("foo", nil)
+    assert_not_called(@cache, :write) do
+      assert_nil @cache.fetch("foo") { "baz" }
+    end
+  end
+
+  def test_fetch_with_forced_cache_miss_with_block
+    @cache.write("foo", "bar")
+    assert_equal "foo_bar", @cache.fetch("foo", force: true) { "foo_bar" }
+  end
+
+  def test_fetch_with_forced_cache_miss_without_block
+    @cache.write("foo", "bar")
+    assert_raises(ArgumentError) do
+      @cache.fetch("foo", force: true)
+    end
+
+    assert_equal "bar", @cache.read("foo")
+  end
+
+  def test_should_read_and_write_hash
+    assert @cache.write("foo", a: "b")
+    assert_equal({ a: "b" }, @cache.read("foo"))
+  end
+
+  def test_should_read_and_write_integer
+    assert @cache.write("foo", 1)
+    assert_equal 1, @cache.read("foo")
+  end
+
+  def test_should_read_and_write_nil
+    assert @cache.write("foo", nil)
+    assert_nil @cache.read("foo")
+  end
+
+  def test_should_read_and_write_false
+    assert @cache.write("foo", false)
+    assert_equal false, @cache.read("foo")
+  end
+
+  def test_read_multi
+    @cache.write("foo", "bar")
+    @cache.write("fu", "baz")
+    @cache.write("fud", "biz")
+    assert_equal({ "foo" => "bar", "fu" => "baz" }, @cache.read_multi("foo", "fu"))
+  end
+
+  def test_read_multi_with_expires
+    time = Time.now
+    @cache.write("foo", "bar", expires_in: 10)
+    @cache.write("fu", "baz")
+    @cache.write("fud", "biz")
+    Time.stub(:now, time + 11) do
+      assert_equal({ "fu" => "baz" }, @cache.read_multi("foo", "fu"))
+    end
+  end
+
+  def test_fetch_multi
+    @cache.write("foo", "bar")
+    @cache.write("fud", "biz")
+
+    values = @cache.fetch_multi("foo", "fu", "fud") { |value| value * 2 }
+
+    assert_equal({ "foo" => "bar", "fu" => "fufu", "fud" => "biz" }, values)
+    assert_equal("fufu", @cache.read("fu"))
+  end
+
+  def test_multi_with_objects
+    cache_struct = Struct.new(:cache_key, :title)
+    foo = cache_struct.new("foo", "FOO!")
+    bar = cache_struct.new("bar")
+
+    @cache.write("bar", "BAM!")
+
+    values = @cache.fetch_multi(foo, bar) { |object| object.title }
+
+    assert_equal({ foo => "FOO!", bar => "BAM!" }, values)
+  end
+
+  def test_fetch_multi_without_block
+    assert_raises(ArgumentError) do
+      @cache.fetch_multi("foo")
+    end
+  end
+
+  def test_read_and_write_compressed_small_data
+    @cache.write("foo", "bar", compress: true)
+    assert_equal "bar", @cache.read("foo")
+  end
+
+  def test_read_and_write_compressed_large_data
+    @cache.write("foo", "bar", compress: true, compress_threshold: 2)
+    assert_equal "bar", @cache.read("foo")
+  end
+
+  def test_read_and_write_compressed_nil
+    @cache.write("foo", nil, compress: true)
+    assert_nil @cache.read("foo")
+  end
+
+  def test_cache_key
+    obj = Object.new
+    def obj.cache_key
+      :foo
+    end
+    @cache.write(obj, "bar")
+    assert_equal "bar", @cache.read("foo")
+  end
+
+  def test_param_as_cache_key
+    obj = Object.new
+    def obj.to_param
+      "foo"
+    end
+    @cache.write(obj, "bar")
+    assert_equal "bar", @cache.read("foo")
+  end
+
+  def test_array_as_cache_key
+    @cache.write([:fu, "foo"], "bar")
+    assert_equal "bar", @cache.read("fu/foo")
+  end
+
+  def test_hash_as_cache_key
+    @cache.write({ foo: 1, fu: 2 }, "bar")
+    assert_equal "bar", @cache.read("foo=1/fu=2")
+  end
+
+  def test_keys_are_case_sensitive
+    @cache.write("foo", "bar")
+    assert_nil @cache.read("FOO")
+  end
+
+  def test_exist
+    @cache.write("foo", "bar")
+    assert_equal true, @cache.exist?("foo")
+    assert_equal false, @cache.exist?("bar")
+  end
+
+  def test_nil_exist
+    @cache.write("foo", nil)
+    assert @cache.exist?("foo")
+  end
+
+  def test_delete
+    @cache.write("foo", "bar")
+    assert @cache.exist?("foo")
+    assert @cache.delete("foo")
+    assert !@cache.exist?("foo")
+  end
+
+  def test_original_store_objects_should_not_be_immutable
+    bar = "bar"
+    @cache.write("foo", bar)
+    assert_nothing_raised { bar.gsub!(/.*/, "baz") }
+  end
+
+  def test_expires_in
+    time = Time.local(2008, 4, 24)
+
+    Time.stub(:now, time) do
+      @cache.write("foo", "bar")
+      assert_equal "bar", @cache.read("foo")
+    end
+
+    Time.stub(:now, time + 30) do
+      assert_equal "bar", @cache.read("foo")
+    end
+
+    Time.stub(:now, time + 61) do
+      assert_nil @cache.read("foo")
+    end
+  end
+
+  def test_race_condition_protection_skipped_if_not_defined
+    @cache.write("foo", "bar")
+    time = @cache.send(:read_entry, @cache.send(:normalize_key, "foo", {}), {}).expires_at
+
+    Time.stub(:now, Time.at(time)) do
+      result = @cache.fetch("foo") do
+        assert_nil @cache.read("foo")
+        "baz"
+      end
+      assert_equal "baz", result
+    end
+  end
+
+  def test_race_condition_protection_is_limited
+    time = Time.now
+    @cache.write("foo", "bar", expires_in: 60)
+    Time.stub(:now, time + 71) do
+      result = @cache.fetch("foo", race_condition_ttl: 10) do
+        assert_nil @cache.read("foo")
+        "baz"
+      end
+      assert_equal "baz", result
+    end
+  end
+
+  def test_race_condition_protection_is_safe
+    time = Time.now
+    @cache.write("foo", "bar", expires_in: 60)
+    Time.stub(:now, time + 61) do
+      begin
+        @cache.fetch("foo", race_condition_ttl: 10) do
+          assert_equal "bar", @cache.read("foo")
+          raise ArgumentError.new
+        end
+      rescue ArgumentError
+      end
+      assert_equal "bar", @cache.read("foo")
+    end
+    Time.stub(:now, time + 91) do
+      assert_nil @cache.read("foo")
+    end
+  end
+
+  def test_race_condition_protection
+    time = Time.now
+    @cache.write("foo", "bar", expires_in: 60)
+    Time.stub(:now, time + 61) do
+      result = @cache.fetch("foo", race_condition_ttl: 10) do
+        assert_equal "bar", @cache.read("foo")
+        "baz"
+      end
+      assert_equal "baz", result
+    end
+  end
+
+  def test_crazy_key_characters
+    crazy_key = "#/:*(<+=> )&$%@?;'\"\'`~-"
+    assert @cache.write(crazy_key, "1", raw: true)
+    assert_equal "1", @cache.read(crazy_key)
+    assert_equal "1", @cache.fetch(crazy_key)
+    assert @cache.delete(crazy_key)
+    assert_equal "2", @cache.fetch(crazy_key, raw: true) { "2" }
+    assert_equal 3, @cache.increment(crazy_key)
+    assert_equal 2, @cache.decrement(crazy_key)
+  end
+
+  def test_really_long_keys
+    key = ""
+    900.times { key << "x" }
+    assert @cache.write(key, "bar")
+    assert_equal "bar", @cache.read(key)
+    assert_equal "bar", @cache.fetch(key)
+    assert_nil @cache.read("#{key}x")
+    assert_equal({ key => "bar" }, @cache.read_multi(key))
+    assert @cache.delete(key)
+  end
+
+  def test_cache_hit_instrumentation
+    key = "test_key"
+    @events = []
+    ActiveSupport::Notifications.subscribe "cache_read.active_support" do |*args|
+      @events << ActiveSupport::Notifications::Event.new(*args)
+    end
+    assert @cache.write(key, "1", raw: true)
+    assert @cache.fetch(key) {}
+    assert_equal 1, @events.length
+    assert_equal "cache_read.active_support", @events[0].name
+    assert_equal :fetch, @events[0].payload[:super_operation]
+    assert @events[0].payload[:hit]
+  ensure
+    ActiveSupport::Notifications.unsubscribe "cache_read.active_support"
+  end
+
+  def test_cache_miss_instrumentation
+    @events = []
+    ActiveSupport::Notifications.subscribe(/^cache_(.*)\.active_support$/) do |*args|
+      @events << ActiveSupport::Notifications::Event.new(*args)
+    end
+    assert_not @cache.fetch("bad_key") {}
+    assert_equal 3, @events.length
+    assert_equal "cache_read.active_support", @events[0].name
+    assert_equal "cache_generate.active_support", @events[1].name
+    assert_equal "cache_write.active_support", @events[2].name
+    assert_equal :fetch, @events[0].payload[:super_operation]
+    assert_not @events[0].payload[:hit]
+  ensure
+    ActiveSupport::Notifications.unsubscribe "cache_read.active_support"
+  end
+end
diff --git a/activesupport/test/cache/behaviors/cache_store_version_behavior.rb b/activesupport/test/cache/behaviors/cache_store_version_behavior.rb
new file mode 100644
index 0000000000..a0170c896f
--- /dev/null
+++ b/activesupport/test/cache/behaviors/cache_store_version_behavior.rb
@@ -0,0 +1,86 @@
+module CacheStoreVersionBehavior
+  ModelWithKeyAndVersion = Struct.new(:cache_key, :cache_version)
+
+  def test_fetch_with_right_version_should_hit
+    @cache.fetch("foo", version: 1) { "bar" }
+    assert_equal "bar", @cache.read("foo", version: 1)
+  end
+
+  def test_fetch_with_wrong_version_should_miss
+    @cache.fetch("foo", version: 1) { "bar" }
+    assert_nil @cache.read("foo", version: 2)
+  end
+
+  def test_read_with_right_version_should_hit
+    @cache.write("foo", "bar", version: 1)
+    assert_equal "bar", @cache.read("foo", version: 1)
+  end
+
+  def test_read_with_wrong_version_should_miss
+    @cache.write("foo", "bar", version: 1)
+    assert_nil @cache.read("foo", version: 2)
+  end
+
+  def test_exist_with_right_version_should_be_true
+    @cache.write("foo", "bar", version: 1)
+    assert @cache.exist?("foo", version: 1)
+  end
+
+  def test_exist_with_wrong_version_should_be_false
+    @cache.write("foo", "bar", version: 1)
+    assert !@cache.exist?("foo", version: 2)
+  end
+
+  def test_reading_and_writing_with_model_supporting_cache_version
+    m1v1 = ModelWithKeyAndVersion.new("model/1", 1)
+    m1v2 = ModelWithKeyAndVersion.new("model/1", 2)
+
+    @cache.write(m1v1, "bar")
+    assert_equal "bar", @cache.read(m1v1)
+    assert_nil @cache.read(m1v2)
+  end
+
+  def test_reading_and_writing_with_model_supporting_cache_version_using_nested_key
+    m1v1 = ModelWithKeyAndVersion.new("model/1", 1)
+    m1v2 = ModelWithKeyAndVersion.new("model/1", 2)
+
+    @cache.write([ "something", m1v1 ], "bar")
+    assert_equal "bar", @cache.read([ "something", m1v1 ])
+    assert_nil @cache.read([ "something", m1v2 ])
+  end
+
+  def test_fetching_with_model_supporting_cache_version
+    m1v1 = ModelWithKeyAndVersion.new("model/1", 1)
+    m1v2 = ModelWithKeyAndVersion.new("model/1", 2)
+
+    @cache.fetch(m1v1) { "bar" }
+    assert_equal "bar", @cache.fetch(m1v1) { "bu" }
+    assert_equal "bu", @cache.fetch(m1v2) { "bu" }
+  end
+
+  def test_exist_with_model_supporting_cache_version
+    m1v1 = ModelWithKeyAndVersion.new("model/1", 1)
+    m1v2 = ModelWithKeyAndVersion.new("model/1", 2)
+
+    @cache.write(m1v1, "bar")
+    assert     @cache.exist?(m1v1)
+    assert_not @cache.fetch(m1v2)
+  end
+
+  def test_fetch_multi_with_model_supporting_cache_version
+    m1v1 = ModelWithKeyAndVersion.new("model/1", 1)
+    m2v1 = ModelWithKeyAndVersion.new("model/2", 1)
+    m2v2 = ModelWithKeyAndVersion.new("model/2", 2)
+
+    first_fetch_values  = @cache.fetch_multi(m1v1, m2v1) { |m| m.cache_key }
+    second_fetch_values = @cache.fetch_multi(m1v1, m2v2) { |m| m.cache_key + " 2nd" }
+
+    assert_equal({ m1v1 => "model/1", m2v1 => "model/2" }, first_fetch_values)
+    assert_equal({ m1v1 => "model/1", m2v2 => "model/2 2nd" }, second_fetch_values)
+  end
+
+  def test_version_is_normalized
+    @cache.write("foo", "bar", version: 1)
+    assert_equal "bar", @cache.read("foo", version: "1")
+  end
+end
diff --git a/activesupport/test/cache/behaviors/encoded_key_cache_behavior.rb b/activesupport/test/cache/behaviors/encoded_key_cache_behavior.rb
new file mode 100644
index 0000000000..4d8e2946b2
--- /dev/null
+++ b/activesupport/test/cache/behaviors/encoded_key_cache_behavior.rb
@@ -0,0 +1,34 @@
+# https://rails.lighthouseapp.com/projects/8994/tickets/6225-memcachestore-cant-deal-with-umlauts-and-special-characters
+# The error is caused by character encodings that can't be compared with ASCII-8BIT regular expressions and by special
+# characters like the umlaut in UTF-8.
+module EncodedKeyCacheBehavior
+  Encoding.list.each do |encoding|
+    define_method "test_#{encoding.name.underscore}_encoded_values" do
+      key = "foo".force_encoding(encoding)
+      assert @cache.write(key, "1", raw: true)
+      assert_equal "1", @cache.read(key)
+      assert_equal "1", @cache.fetch(key)
+      assert @cache.delete(key)
+      assert_equal "2", @cache.fetch(key, raw: true) { "2" }
+      assert_equal 3, @cache.increment(key)
+      assert_equal 2, @cache.decrement(key)
+    end
+  end
+
+  def test_common_utf8_values
+    key = "\xC3\xBCmlaut".force_encoding(Encoding::UTF_8)
+    assert @cache.write(key, "1", raw: true)
+    assert_equal "1", @cache.read(key)
+    assert_equal "1", @cache.fetch(key)
+    assert @cache.delete(key)
+    assert_equal "2", @cache.fetch(key, raw: true) { "2" }
+    assert_equal 3, @cache.increment(key)
+    assert_equal 2, @cache.decrement(key)
+  end
+
+  def test_retains_encoding
+    key = "\xC3\xBCmlaut".force_encoding(Encoding::UTF_8)
+    assert @cache.write(key, "1", raw: true)
+    assert_equal Encoding::UTF_8, key.encoding
+  end
+end
diff --git a/activesupport/test/cache/behaviors/local_cache_behavior.rb b/activesupport/test/cache/behaviors/local_cache_behavior.rb
new file mode 100644
index 0000000000..8530296374
--- /dev/null
+++ b/activesupport/test/cache/behaviors/local_cache_behavior.rb
@@ -0,0 +1,126 @@
+module LocalCacheBehavior
+  def test_local_writes_are_persistent_on_the_remote_cache
+    retval = @cache.with_local_cache do
+      @cache.write("foo", "bar")
+    end
+    assert retval
+    assert_equal "bar", @cache.read("foo")
+  end
+
+  def test_clear_also_clears_local_cache
+    @cache.with_local_cache do
+      @cache.write("foo", "bar")
+      @cache.clear
+      assert_nil @cache.read("foo")
+    end
+
+    assert_nil @cache.read("foo")
+  end
+
+  def test_cleanup_clears_local_cache_but_not_remote_cache
+    skip unless @cache.class.instance_methods(false).include?(:cleanup)
+
+    @cache.with_local_cache do
+      @cache.write("foo", "bar")
+      assert_equal "bar", @cache.read("foo")
+
+      @cache.send(:bypass_local_cache) { @cache.write("foo", "baz") }
+      assert_equal "bar", @cache.read("foo")
+
+      @cache.cleanup
+      assert_equal "baz", @cache.read("foo")
+    end
+  end
+
+  def test_local_cache_of_write
+    @cache.with_local_cache do
+      @cache.write("foo", "bar")
+      @peek.delete("foo")
+      assert_equal "bar", @cache.read("foo")
+    end
+  end
+
+  def test_local_cache_of_read
+    @cache.write("foo", "bar")
+    @cache.with_local_cache do
+      assert_equal "bar", @cache.read("foo")
+    end
+  end
+
+  def test_local_cache_of_read_nil
+    @cache.with_local_cache do
+      assert_nil @cache.read("foo")
+      @cache.send(:bypass_local_cache) { @cache.write "foo", "bar" }
+      assert_nil @cache.read("foo")
+    end
+  end
+
+  def test_local_cache_fetch
+    @cache.with_local_cache do
+      @cache.send(:local_cache).write "foo", "bar"
+      assert_equal "bar", @cache.send(:local_cache).fetch("foo")
+    end
+  end
+
+  def test_local_cache_of_write_nil
+    @cache.with_local_cache do
+      assert @cache.write("foo", nil)
+      assert_nil @cache.read("foo")
+      @peek.write("foo", "bar")
+      assert_nil @cache.read("foo")
+    end
+  end
+
+  def test_local_cache_of_write_with_unless_exist
+    @cache.with_local_cache do
+      @cache.write("foo", "bar")
+      @cache.write("foo", "baz", unless_exist: true)
+      assert_equal @peek.read("foo"), @cache.read("foo")
+    end
+  end
+
+  def test_local_cache_of_delete
+    @cache.with_local_cache do
+      @cache.write("foo", "bar")
+      @cache.delete("foo")
+      assert_nil @cache.read("foo")
+    end
+  end
+
+  def test_local_cache_of_exist
+    @cache.with_local_cache do
+      @cache.write("foo", "bar")
+      @peek.delete("foo")
+      assert @cache.exist?("foo")
+    end
+  end
+
+  def test_local_cache_of_increment
+    @cache.with_local_cache do
+      @cache.write("foo", 1, raw: true)
+      @peek.write("foo", 2, raw: true)
+      @cache.increment("foo")
+      assert_equal 3, @cache.read("foo")
+    end
+  end
+
+  def test_local_cache_of_decrement
+    @cache.with_local_cache do
+      @cache.write("foo", 1, raw: true)
+      @peek.write("foo", 3, raw: true)
+      @cache.decrement("foo")
+      assert_equal 2, @cache.read("foo")
+    end
+  end
+
+  def test_middleware
+    app = lambda { |env|
+      result = @cache.write("foo", "bar")
+      assert_equal "bar", @cache.read("foo") # make sure 'foo' was written
+      assert result
+      [200, {}, []]
+    }
+    app = @cache.middleware.new(app)
+    app.call({})
+  end
+end
diff --git a/activesupport/test/cache/cache_entry_test.rb b/activesupport/test/cache/cache_entry_test.rb
new file mode 100644
index 0000000000..e446e39b10
--- /dev/null
+++ b/activesupport/test/cache/cache_entry_test.rb
@@ -0,0 +1,28 @@
+require "abstract_unit"
+require "active_support/cache"
+
+class CacheEntryTest < ActiveSupport::TestCase
+  def test_expired
+    entry = ActiveSupport::Cache::Entry.new("value")
+    assert !entry.expired?, "entry not expired"
+    entry = ActiveSupport::Cache::Entry.new("value", expires_in: 60)
+    assert !entry.expired?, "entry not expired"
+    Time.stub(:now, Time.now + 61) do
+      assert entry.expired?, "entry is expired"
+    end
+  end
+
+  def test_compress_values
+    value = "value" * 100
+    entry = ActiveSupport::Cache::Entry.new(value, compress: true, compress_threshold: 1)
+    assert_equal value, entry.value
+    assert(value.bytesize > entry.size, "value is compressed")
+  end
+
+  def test_non_compress_values
+    value = "value" * 100
+    entry = ActiveSupport::Cache::Entry.new(value)
+    assert_equal value, entry.value
+    assert_equal value.bytesize, entry.size
+  end
+end
diff --git a/activesupport/test/cache/cache_key_test.rb b/activesupport/test/cache/cache_key_test.rb
new file mode 100644
index 0000000000..149d0f66ee
--- /dev/null
+++ b/activesupport/test/cache/cache_key_test.rb
@@ -0,0 +1,88 @@
+require "abstract_unit"
+require "active_support/cache"
+
+class CacheKeyTest < ActiveSupport::TestCase
+  def test_entry_legacy_optional_ivars
+    legacy = Class.new(ActiveSupport::Cache::Entry) do
+      def initialize(value, options = {})
+        @value = value
+        @expires_in = nil
+        @created_at = nil
+        super
+      end
+    end
+
+    entry = legacy.new "foo"
+    assert_equal "foo", entry.value
+  end
+
+  def test_expand_cache_key
+    assert_equal "1/2/true", ActiveSupport::Cache.expand_cache_key([1, "2", true])
+    assert_equal "name/1/2/true", ActiveSupport::Cache.expand_cache_key([1, "2", true], :name)
+  end
+
+  def test_expand_cache_key_with_rails_cache_id
+    with_env("RAILS_CACHE_ID" => "c99") do
+      assert_equal "c99/foo", ActiveSupport::Cache.expand_cache_key(:foo)
+      assert_equal "c99/foo", ActiveSupport::Cache.expand_cache_key([:foo])
+      assert_equal "c99/foo/bar", ActiveSupport::Cache.expand_cache_key([:foo, :bar])
+      assert_equal "nm/c99/foo", ActiveSupport::Cache.expand_cache_key(:foo, :nm)
+      assert_equal "nm/c99/foo", ActiveSupport::Cache.expand_cache_key([:foo], :nm)
+      assert_equal "nm/c99/foo/bar", ActiveSupport::Cache.expand_cache_key([:foo, :bar], :nm)
+    end
+  end
+
+  def test_expand_cache_key_with_rails_app_version
+    with_env("RAILS_APP_VERSION" => "rails3") do
+      assert_equal "rails3/foo", ActiveSupport::Cache.expand_cache_key(:foo)
+    end
+  end
+
+  def test_expand_cache_key_rails_cache_id_should_win_over_rails_app_version
+    with_env("RAILS_CACHE_ID" => "c99", "RAILS_APP_VERSION" => "rails3") do
+      assert_equal "c99/foo", ActiveSupport::Cache.expand_cache_key(:foo)
+    end
+  end
+
+  def test_expand_cache_key_respond_to_cache_key
+    key = "foo"
+    def key.cache_key
+      :foo_key
+    end
+    assert_equal "foo_key", ActiveSupport::Cache.expand_cache_key(key)
+  end
+
+  def test_expand_cache_key_array_with_something_that_responds_to_cache_key
+    key = "foo"
+    def key.cache_key
+      :foo_key
+    end
+    assert_equal "foo_key", ActiveSupport::Cache.expand_cache_key([key])
+  end
+
+  def test_expand_cache_key_of_nil
+    assert_equal "", ActiveSupport::Cache.expand_cache_key(nil)
+  end
+
+  def test_expand_cache_key_of_false
+    assert_equal "false", ActiveSupport::Cache.expand_cache_key(false)
+  end
+
+  def test_expand_cache_key_of_true
+    assert_equal "true", ActiveSupport::Cache.expand_cache_key(true)
+  end
+
+  def test_expand_cache_key_of_array_like_object
+    assert_equal "foo/bar/baz", ActiveSupport::Cache.expand_cache_key(%w{foo bar baz}.to_enum)
+  end
+
+  private
+
+    def with_env(kv)
+      old_values = {}
+      kv.each { |key, value| old_values[key], ENV[key] = ENV[key], value }
+      yield
+    ensure
+      old_values.each { |key, value| ENV[key] = value }
+    end
+end
diff --git a/activesupport/test/cache/cache_store_logger_test.rb b/activesupport/test/cache/cache_store_logger_test.rb
new file mode 100644
index 0000000000..621cfebb10
--- /dev/null
+++ b/activesupport/test/cache/cache_store_logger_test.rb
@@ -0,0 +1,34 @@
+require "abstract_unit"
+require "active_support/cache"
+
+class CacheStoreLoggerTest < ActiveSupport::TestCase
+  def setup
+    @cache = ActiveSupport::Cache.lookup_store(:memory_store)
+
+    @buffer = StringIO.new
+    @cache.logger = ActiveSupport::Logger.new(@buffer)
+  end
+
+  def test_logging
+    @cache.fetch("foo") { "bar" }
+    assert @buffer.string.present?
+  end
+
+  def test_log_with_string_namespace
+    @cache.fetch("foo", namespace: "string_namespace") { "bar" }
+    assert_match %r{string_namespace:foo}, @buffer.string
+  end
+
+  def test_log_with_proc_namespace
+    proc = Proc.new do
+      "proc_namespace"
+    end
+    @cache.fetch("foo", namespace: proc) { "bar" }
+    assert_match %r{proc_namespace:foo}, @buffer.string
+  end
+
+  def test_mute_logging
+    @cache.mute { @cache.fetch("foo") { "bar" } }
+    assert @buffer.string.blank?
+  end
+end
diff --git a/activesupport/test/cache/cache_store_namespace_test.rb b/activesupport/test/cache/cache_store_namespace_test.rb
new file mode 100644
index 0000000000..e395c88271
--- /dev/null
+++ b/activesupport/test/cache/cache_store_namespace_test.rb
@@ -0,0 +1,38 @@
+require "abstract_unit"
+require "active_support/cache"
+
+class CacheStoreNamespaceTest < ActiveSupport::TestCase
+  def test_static_namespace
+    cache = ActiveSupport::Cache.lookup_store(:memory_store, namespace: "tester")
+    cache.write("foo", "bar")
+    assert_equal "bar", cache.read("foo")
+    assert_equal "bar", cache.instance_variable_get(:@data)["tester:foo"].value
+  end
+
+  def test_proc_namespace
+    test_val = "tester"
+    proc = lambda { test_val }
+    cache = ActiveSupport::Cache.lookup_store(:memory_store, namespace: proc)
+    cache.write("foo", "bar")
+    assert_equal "bar", cache.read("foo")
+    assert_equal "bar", cache.instance_variable_get(:@data)["tester:foo"].value
+  end
+
+  def test_delete_matched_key_start
+    cache = ActiveSupport::Cache.lookup_store(:memory_store, namespace: "tester")
+    cache.write("foo", "bar")
+    cache.write("fu", "baz")
+    cache.delete_matched(/^fo/)
+    assert !cache.exist?("foo")
+    assert cache.exist?("fu")
+  end
+
+  def test_delete_matched_key
+    cache = ActiveSupport::Cache.lookup_store(:memory_store, namespace: "foo")
+    cache.write("foo", "bar")
+    cache.write("fu", "baz")
+    cache.delete_matched(/OO/i)
+    assert !cache.exist?("foo")
+    assert cache.exist?("fu")
+  end
+end
diff --git a/activesupport/test/cache/cache_store_setting_test.rb b/activesupport/test/cache/cache_store_setting_test.rb
new file mode 100644
index 0000000000..cb9b006abe
--- /dev/null
+++ b/activesupport/test/cache/cache_store_setting_test.rb
@@ -0,0 +1,66 @@
+require "abstract_unit"
+require "active_support/cache"
+require "dalli"
+
+class CacheStoreSettingTest < ActiveSupport::TestCase
+  def test_memory_store_gets_created_if_no_arguments_passed_to_lookup_store_method
+    store = ActiveSupport::Cache.lookup_store
+    assert_kind_of(ActiveSupport::Cache::MemoryStore, store)
+  end
+
+  def test_memory_store
+    store = ActiveSupport::Cache.lookup_store :memory_store
+    assert_kind_of(ActiveSupport::Cache::MemoryStore, store)
+  end
+
+  def test_file_fragment_cache_store
+    store = ActiveSupport::Cache.lookup_store :file_store, "/path/to/cache/directory"
+    assert_kind_of(ActiveSupport::Cache::FileStore, store)
+    assert_equal "/path/to/cache/directory", store.cache_path
+  end
+
+  def test_mem_cache_fragment_cache_store
+    assert_called_with(Dalli::Client, :new, [%w[localhost], {}]) do
+      store = ActiveSupport::Cache.lookup_store :mem_cache_store, "localhost"
+      assert_kind_of(ActiveSupport::Cache::MemCacheStore, store)
+    end
+  end
+
+  def test_mem_cache_fragment_cache_store_with_given_mem_cache
+    mem_cache = Dalli::Client.new
+    assert_not_called(Dalli::Client, :new) do
+      store = ActiveSupport::Cache.lookup_store :mem_cache_store, mem_cache
+      assert_kind_of(ActiveSupport::Cache::MemCacheStore, store)
+    end
+  end
+
+  def test_mem_cache_fragment_cache_store_with_not_dalli_client
+    assert_not_called(Dalli::Client, :new) do
+      memcache = Object.new
+      assert_raises(ArgumentError) do
+        ActiveSupport::Cache.lookup_store :mem_cache_store, memcache
+      end
+    end
+  end
+
+  def test_mem_cache_fragment_cache_store_with_multiple_servers
+    assert_called_with(Dalli::Client, :new, [%w[localhost 192.168.1.1], {}]) do
+      store = ActiveSupport::Cache.lookup_store :mem_cache_store, "localhost", "192.168.1.1"
+      assert_kind_of(ActiveSupport::Cache::MemCacheStore, store)
+    end
+  end
+
+  def test_mem_cache_fragment_cache_store_with_options
+    assert_called_with(Dalli::Client, :new, [%w[localhost 192.168.1.1], { timeout: 10 }]) do
+      store = ActiveSupport::Cache.lookup_store :mem_cache_store, "localhost", "192.168.1.1", namespace: "foo", timeout: 10
+      assert_kind_of(ActiveSupport::Cache::MemCacheStore, store)
+      assert_equal "foo", store.options[:namespace]
+    end
+  end
+
+  def test_object_assigned_fragment_cache_store
+    store = ActiveSupport::Cache.lookup_store ActiveSupport::Cache::FileStore.new("/path/to/cache/directory")
+    assert_kind_of(ActiveSupport::Cache::FileStore, store)
+    assert_equal "/path/to/cache/directory", store.cache_path
+  end
+end
diff --git a/activesupport/test/cache/cache_store_write_multi_test.rb b/activesupport/test/cache/cache_store_write_multi_test.rb
new file mode 100644
index 0000000000..16e3f3b842
--- /dev/null
+++ b/activesupport/test/cache/cache_store_write_multi_test.rb
@@ -0,0 +1,60 @@
+require "abstract_unit"
+require "active_support/cache"
+
+class CacheStoreWriteMultiEntriesStoreProviderInterfaceTest < ActiveSupport::TestCase
+  setup do
+    @cache = ActiveSupport::Cache.lookup_store(:null_store)
+  end
+
+  test "fetch_multi uses write_multi_entries store provider interface" do
+    assert_called_with(@cache, :write_multi_entries) do
+      @cache.fetch_multi "a", "b", "c" do |key|
+        key * 2
+      end
+    end
+  end
+end
+
+class CacheStoreWriteMultiInstrumentationTest < ActiveSupport::TestCase
+  setup do
+    @cache = ActiveSupport::Cache.lookup_store(:null_store)
+  end
+
+  test "instrumentation" do
+    writes = { "a" => "aa", "b" => "bb" }
+
+    events = with_instrumentation "write_multi" do
+      @cache.write_multi(writes)
+    end
+
+    assert_equal %w[ cache_write_multi.active_support ], events.map(&:name)
+    assert_nil events[0].payload[:super_operation]
+    assert_equal({ "a" => "aa", "b" => "bb" }, events[0].payload[:key])
+  end
+
+  test "instrumentation with fetch_multi as super operation" do
+    skip "fetch_multi isn't instrumented yet"
+
+    events = with_instrumentation "write_multi" do
+      @cache.fetch_multi("a", "b") { |key| key * 2 }
+    end
+
+    assert_equal %w[ cache_write_multi.active_support ], events.map(&:name)
+    assert_nil events[0].payload[:super_operation]
+    assert !events[0].payload[:hit]
+  end
+
+  private
+    def with_instrumentation(method)
+      event_name = "cache_#{method}.active_support"
+
+      [].tap do |events|
+        ActiveSupport::Notifications.subscribe event_name do |*args|
+          events << ActiveSupport::Notifications::Event.new(*args)
+        end
+        yield
+      end
+    ensure
+      ActiveSupport::Notifications.unsubscribe event_name
+    end
+end
diff --git a/activesupport/test/cache/local_cache_middleware_test.rb b/activesupport/test/cache/local_cache_middleware_test.rb
new file mode 100644
index 0000000000..352502fb43
--- /dev/null
+++ b/activesupport/test/cache/local_cache_middleware_test.rb
@@ -0,0 +1,61 @@
+require "abstract_unit"
+require "active_support/cache"
+
+module ActiveSupport
+  module Cache
+    module Strategy
+      module LocalCache
+        class MiddlewareTest < ActiveSupport::TestCase
+          def test_local_cache_cleared_on_close
+            key = "super awesome key"
+            assert_nil LocalCacheRegistry.cache_for key
+            middleware = Middleware.new("<3", key).new(->(env) {
+              assert LocalCacheRegistry.cache_for(key), "should have a cache"
+              [200, {}, []]
+            })
+            _, _, body = middleware.call({})
+            assert LocalCacheRegistry.cache_for(key), "should still have a cache"
+            body.each {}
+            assert LocalCacheRegistry.cache_for(key), "should still have a cache"
+            body.close
+            assert_nil LocalCacheRegistry.cache_for(key)
+          end
+
+          def test_local_cache_cleared_and_response_should_be_present_on_invalid_parameters_error
+            key = "super awesome key"
+            assert_nil LocalCacheRegistry.cache_for key
+            middleware = Middleware.new("<3", key).new(->(env) {
+              assert LocalCacheRegistry.cache_for(key), "should have a cache"
+              raise Rack::Utils::InvalidParameterError
+            })
+            response = middleware.call({})
+            assert response, "response should exist"
+            assert_nil LocalCacheRegistry.cache_for(key)
+          end
+
+          def test_local_cache_cleared_on_exception
+            key = "super awesome key"
+            assert_nil LocalCacheRegistry.cache_for key
+            middleware = Middleware.new("<3", key).new(->(env) {
+              assert LocalCacheRegistry.cache_for(key), "should have a cache"
+              raise
+            })
+            assert_raises(RuntimeError) { middleware.call({}) }
+            assert_nil LocalCacheRegistry.cache_for(key)
+          end
+
+          def test_local_cache_cleared_on_throw
+            key = "super awesome key"
+            assert_nil LocalCacheRegistry.cache_for key
+            middleware = Middleware.new("<3", key).new(->(env) {
+              assert LocalCacheRegistry.cache_for(key), "should have a cache"
+              throw :warden
+            })
+            assert_throws(:warden) { middleware.call({}) }
+            assert_nil LocalCacheRegistry.cache_for(key)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activesupport/test/cache/stores/file_store_test.rb b/activesupport/test/cache/stores/file_store_test.rb
new file mode 100644
index 0000000000..48b304fe6e
--- /dev/null
+++ b/activesupport/test/cache/stores/file_store_test.rb
@@ -0,0 +1,128 @@
+require "abstract_unit"
+require "active_support/cache"
+require_relative "../behaviors"
+require "pathname"
+
+class FileStoreTest < ActiveSupport::TestCase
+  def setup
+    Dir.mkdir(cache_dir) unless File.exist?(cache_dir)
+    @cache = ActiveSupport::Cache.lookup_store(:file_store, cache_dir, expires_in: 60)
+    @peek = ActiveSupport::Cache.lookup_store(:file_store, cache_dir, expires_in: 60)
+    @cache_with_pathname = ActiveSupport::Cache.lookup_store(:file_store, Pathname.new(cache_dir), expires_in: 60)
+
+    @buffer = StringIO.new
+    @cache.logger = ActiveSupport::Logger.new(@buffer)
+  end
+
+  def teardown
+    FileUtils.rm_r(cache_dir)
+  rescue Errno::ENOENT
+  end
+
+  def cache_dir
+    File.join(Dir.pwd, "tmp_cache")
+  end
+
+  include CacheStoreBehavior
+  include CacheStoreVersionBehavior
+  include LocalCacheBehavior
+  include CacheDeleteMatchedBehavior
+  include CacheIncrementDecrementBehavior
+  include AutoloadingCacheBehavior
+
+  def test_clear
+    gitkeep = File.join(cache_dir, ".gitkeep")
+    keep = File.join(cache_dir, ".keep")
+    FileUtils.touch([gitkeep, keep])
+    @cache.clear
+    assert File.exist?(gitkeep)
+    assert File.exist?(keep)
+  end
+
+  def test_clear_without_cache_dir
+    FileUtils.rm_r(cache_dir)
+    @cache.clear
+  end
+
+  def test_long_uri_encoded_keys
+    @cache.write("%" * 870, 1)
+    assert_equal 1, @cache.read("%" * 870)
+  end
+
+  def test_key_transformation
+    key = @cache.send(:normalize_key, "views/index?id=1", {})
+    assert_equal "views/index?id=1", @cache.send(:file_path_key, key)
+  end
+
+  def test_key_transformation_with_pathname
+    FileUtils.touch(File.join(cache_dir, "foo"))
+    key = @cache_with_pathname.send(:normalize_key, "views/index?id=1", {})
+    assert_equal "views/index?id=1", @cache_with_pathname.send(:file_path_key, key)
+  end
+
+  # Test that generated cache keys are short enough to have Tempfile stuff added to them and
+  # remain valid
+  def test_filename_max_size
+    key = "#{'A' * ActiveSupport::Cache::FileStore::FILENAME_MAX_SIZE}"
+    path = @cache.send(:normalize_key, key, {})
+    Dir::Tmpname.create(path) do |tmpname, n, opts|
+      assert File.basename(tmpname + ".lock").length <= 255, "Temp filename too long: #{File.basename(tmpname + '.lock').length}"
+    end
+  end
+
+  # Because file systems have a maximum filename size, filenames > max size should be split in to directories
+  # If filename is 'AAAAB', where max size is 4, the returned path should be AAAA/B
+  def test_key_transformation_max_filename_size
+    key = "#{'A' * ActiveSupport::Cache::FileStore::FILENAME_MAX_SIZE}B"
+    path = @cache.send(:normalize_key, key, {})
+    assert path.split("/").all? { |dir_name| dir_name.size <= ActiveSupport::Cache::FileStore::FILENAME_MAX_SIZE }
+    assert_equal "B", File.basename(path)
+  end
+
+  # If nothing has been stored in the cache, there is a chance the cache directory does not yet exist
+  # Ensure delete_matched gracefully handles this case
+  def test_delete_matched_when_cache_directory_does_not_exist
+    assert_nothing_raised do
+      ActiveSupport::Cache::FileStore.new("/test/cache/directory").delete_matched(/does_not_exist/)
+    end
+  end
+
+  def test_delete_does_not_delete_empty_parent_dir
+    sub_cache_dir = File.join(cache_dir, "subdir/")
+    sub_cache_store = ActiveSupport::Cache::FileStore.new(sub_cache_dir)
+    assert_nothing_raised do
+      assert sub_cache_store.write("foo", "bar")
+      assert sub_cache_store.delete("foo")
+    end
+    assert File.exist?(cache_dir), "Parent of top level cache dir was deleted!"
+    assert File.exist?(sub_cache_dir), "Top level cache dir was deleted!"
+    assert Dir.entries(sub_cache_dir).reject { |f| ActiveSupport::Cache::FileStore::EXCLUDED_DIRS.include?(f) }.empty?
+  end
+
+  def test_log_exception_when_cache_read_fails
+    File.stub(:exist?, -> { raise StandardError.new("failed") }) do
+      @cache.send(:read_entry, "winston", {})
+      assert @buffer.string.present?
+    end
+  end
+
+  def test_cleanup_removes_all_expired_entries
+    time = Time.now
+    @cache.write("foo", "bar", expires_in: 10)
+    @cache.write("baz", "qux")
+    @cache.write("quux", "corge", expires_in: 20)
+    Time.stub(:now, time + 15) do
+      @cache.cleanup
+      assert_not @cache.exist?("foo")
+      assert @cache.exist?("baz")
+      assert @cache.exist?("quux")
+    end
+  end
+
+  def test_write_with_unless_exist
+    assert_equal true, @cache.write(1, "aaaaaaaaaa")
+    assert_equal false, @cache.write(1, "aaaaaaaaaa", unless_exist: true)
+    @cache.write(1, nil)
+    assert_equal false, @cache.write(1, "aaaaaaaaaa", unless_exist: true)
+  end
+end
diff --git a/activesupport/test/cache/stores/mem_cache_store_test.rb b/activesupport/test/cache/stores/mem_cache_store_test.rb
new file mode 100644
index 0000000000..2dd5264818
--- /dev/null
+++ b/activesupport/test/cache/stores/mem_cache_store_test.rb
@@ -0,0 +1,74 @@
+require "abstract_unit"
+require "active_support/cache"
+require_relative "../behaviors"
+require "dalli"
+
+class MemCacheStoreTest < ActiveSupport::TestCase
+  begin
+    ss = Dalli::Client.new("localhost:11211").stats
+    raise Dalli::DalliError unless ss["localhost:11211"]
+
+    MEMCACHE_UP = true
+  rescue Dalli::DalliError
+    $stderr.puts "Skipping memcached tests. Start memcached and try again."
+    MEMCACHE_UP = false
+  end
+
+  def setup
+    skip "memcache server is not up" unless MEMCACHE_UP
+
+    @cache = ActiveSupport::Cache.lookup_store(:mem_cache_store, expires_in: 60)
+    @peek = ActiveSupport::Cache.lookup_store(:mem_cache_store)
+    @data = @cache.instance_variable_get(:@data)
+    @cache.clear
+    @cache.silence!
+    @cache.logger = ActiveSupport::Logger.new("/dev/null")
+  end
+
+  include CacheStoreBehavior
+  include CacheStoreVersionBehavior
+  include LocalCacheBehavior
+  include CacheIncrementDecrementBehavior
+  include EncodedKeyCacheBehavior
+  include AutoloadingCacheBehavior
+
+  def test_raw_values
+    cache = ActiveSupport::Cache.lookup_store(:mem_cache_store, raw: true)
+    cache.clear
+    cache.write("foo", 2)
+    assert_equal "2", cache.read("foo")
+  end
+
+  def test_raw_values_with_marshal
+    cache = ActiveSupport::Cache.lookup_store(:mem_cache_store, raw: true)
+    cache.clear
+    cache.write("foo", Marshal.dump([]))
+    assert_equal [], cache.read("foo")
+  end
+
+  def test_local_cache_raw_values
+    cache = ActiveSupport::Cache.lookup_store(:mem_cache_store, raw: true)
+    cache.clear
+    cache.with_local_cache do
+      cache.write("foo", 2)
+      assert_equal "2", cache.read("foo")
+    end
+  end
+
+  def test_local_cache_raw_values_with_marshal
+    cache = ActiveSupport::Cache.lookup_store(:mem_cache_store, raw: true)
+    cache.clear
+    cache.with_local_cache do
+      cache.write("foo", Marshal.dump([]))
+      assert_equal [], cache.read("foo")
+    end
+  end
+
+  def test_read_should_return_a_different_object_id_each_time_it_is_called
+    @cache.write("foo", "bar")
+    value = @cache.read("foo")
+    assert_not_equal value.object_id, @cache.read("foo").object_id
+    value << "bingo"
+    assert_not_equal value, @cache.read("foo")
+  end
+end
diff --git a/activesupport/test/cache/stores/memory_store_test.rb b/activesupport/test/cache/stores/memory_store_test.rb
new file mode 100644
index 0000000000..3dd1646d56
--- /dev/null
+++ b/activesupport/test/cache/stores/memory_store_test.rb
@@ -0,0 +1,107 @@
+require "abstract_unit"
+require "active_support/cache"
+require_relative "../behaviors"
+
+class MemoryStoreTest < ActiveSupport::TestCase
+  def setup
+    @record_size = ActiveSupport::Cache.lookup_store(:memory_store).send(:cached_size, 1, ActiveSupport::Cache::Entry.new("aaaaaaaaaa"))
+    @cache = ActiveSupport::Cache.lookup_store(:memory_store, expires_in: 60, size: @record_size * 10 + 1)
+  end
+
+  include CacheStoreBehavior
+  include CacheStoreVersionBehavior
+  include CacheDeleteMatchedBehavior
+  include CacheIncrementDecrementBehavior
+
+  def test_prune_size
+    @cache.write(1, "aaaaaaaaaa") && sleep(0.001)
+    @cache.write(2, "bbbbbbbbbb") && sleep(0.001)
+    @cache.write(3, "cccccccccc") && sleep(0.001)
+    @cache.write(4, "dddddddddd") && sleep(0.001)
+    @cache.write(5, "eeeeeeeeee") && sleep(0.001)
+    @cache.read(2) && sleep(0.001)
+    @cache.read(4)
+    @cache.prune(@record_size * 3)
+    assert @cache.exist?(5)
+    assert @cache.exist?(4)
+    assert !@cache.exist?(3), "no entry"
+    assert @cache.exist?(2)
+    assert !@cache.exist?(1), "no entry"
+  end
+
+  def test_prune_size_on_write
+    @cache.write(1, "aaaaaaaaaa") && sleep(0.001)
+    @cache.write(2, "bbbbbbbbbb") && sleep(0.001)
+    @cache.write(3, "cccccccccc") && sleep(0.001)
+    @cache.write(4, "dddddddddd") && sleep(0.001)
+    @cache.write(5, "eeeeeeeeee") && sleep(0.001)
+    @cache.write(6, "ffffffffff") && sleep(0.001)
+    @cache.write(7, "gggggggggg") && sleep(0.001)
+    @cache.write(8, "hhhhhhhhhh") && sleep(0.001)
+    @cache.write(9, "iiiiiiiiii") && sleep(0.001)
+    @cache.write(10, "kkkkkkkkkk") && sleep(0.001)
+    @cache.read(2) && sleep(0.001)
+    @cache.read(4) && sleep(0.001)
+    @cache.write(11, "llllllllll")
+    assert @cache.exist?(11)
+    assert @cache.exist?(10)
+    assert @cache.exist?(9)
+    assert @cache.exist?(8)
+    assert @cache.exist?(7)
+    assert !@cache.exist?(6), "no entry"
+    assert !@cache.exist?(5), "no entry"
+    assert @cache.exist?(4)
+    assert !@cache.exist?(3), "no entry"
+    assert @cache.exist?(2)
+    assert !@cache.exist?(1), "no entry"
+  end
+
+  def test_prune_size_on_write_based_on_key_length
+    @cache.write(1, "aaaaaaaaaa") && sleep(0.001)
+    @cache.write(2, "bbbbbbbbbb") && sleep(0.001)
+    @cache.write(3, "cccccccccc") && sleep(0.001)
+    @cache.write(4, "dddddddddd") && sleep(0.001)
+    @cache.write(5, "eeeeeeeeee") && sleep(0.001)
+    @cache.write(6, "ffffffffff") && sleep(0.001)
+    @cache.write(7, "gggggggggg") && sleep(0.001)
+    @cache.write(8, "hhhhhhhhhh") && sleep(0.001)
+    @cache.write(9, "iiiiiiiiii") && sleep(0.001)
+    long_key = "*" * 2 * @record_size
+    @cache.write(long_key, "llllllllll")
+    assert @cache.exist?(long_key)
+    assert @cache.exist?(9)
+    assert @cache.exist?(8)
+    assert @cache.exist?(7)
+    assert @cache.exist?(6)
+    assert !@cache.exist?(5), "no entry"
+    assert !@cache.exist?(4), "no entry"
+    assert !@cache.exist?(3), "no entry"
+    assert !@cache.exist?(2), "no entry"
+    assert !@cache.exist?(1), "no entry"
+  end
+
+  def test_pruning_is_capped_at_a_max_time
+    def @cache.delete_entry(*args)
+      sleep(0.01)
+      super
+    end
+    @cache.write(1, "aaaaaaaaaa") && sleep(0.001)
+    @cache.write(2, "bbbbbbbbbb") && sleep(0.001)
+    @cache.write(3, "cccccccccc") && sleep(0.001)
+    @cache.write(4, "dddddddddd") && sleep(0.001)
+    @cache.write(5, "eeeeeeeeee") && sleep(0.001)
+    @cache.prune(30, 0.001)
+    assert @cache.exist?(5)
+    assert @cache.exist?(4)
+    assert @cache.exist?(3)
+    assert @cache.exist?(2)
+    assert !@cache.exist?(1)
+  end
+
+  def test_write_with_unless_exist
+    assert_equal true, @cache.write(1, "aaaaaaaaaa")
+    assert_equal false, @cache.write(1, "aaaaaaaaaa", unless_exist: true)
+    @cache.write(1, nil)
+    assert_equal false, @cache.write(1, "aaaaaaaaaa", unless_exist: true)
+  end
+end
diff --git a/activesupport/test/cache/stores/null_store_test.rb b/activesupport/test/cache/stores/null_store_test.rb
new file mode 100644
index 0000000000..23c4e64ee4
--- /dev/null
+++ b/activesupport/test/cache/stores/null_store_test.rb
@@ -0,0 +1,57 @@
+require "abstract_unit"
+require "active_support/cache"
+require_relative "../behaviors"
+
+class NullStoreTest < ActiveSupport::TestCase
+  def setup
+    @cache = ActiveSupport::Cache.lookup_store(:null_store)
+  end
+
+  def test_clear
+    @cache.clear
+  end
+
+  def test_cleanup
+    @cache.cleanup
+  end
+
+  def test_write
+    assert_equal true, @cache.write("name", "value")
+  end
+
+  def test_read
+    @cache.write("name", "value")
+    assert_nil @cache.read("name")
+  end
+
+  def test_delete
+    @cache.write("name", "value")
+    assert_equal false, @cache.delete("name")
+  end
+
+  def test_increment
+    @cache.write("name", 1, raw: true)
+    assert_nil @cache.increment("name")
+  end
+
+  def test_decrement
+    @cache.write("name", 1, raw: true)
+    assert_nil @cache.increment("name")
+  end
+
+  def test_delete_matched
+    @cache.write("name", "value")
+    @cache.delete_matched(/name/)
+  end
+
+  def test_local_store_strategy
+    @cache.with_local_cache do
+      @cache.write("name", "value")
+      assert_equal "value", @cache.read("name")
+      @cache.delete("name")
+      assert_nil @cache.read("name")
+      @cache.write("name", "value")
+    end
+    assert_nil @cache.read("name")
+  end
+end
diff --git a/activesupport/test/caching_test.rb b/activesupport/test/caching_test.rb
deleted file mode 100644
index dbec684ce0..0000000000
--- a/activesupport/test/caching_test.rb
+++ /dev/null
@@ -1,1211 +0,0 @@
-require "logger"
-require "abstract_unit"
-require "active_support/cache"
-require "dependencies_test_helpers"
-
-require "pathname"
-
-module ActiveSupport
-  module Cache
-    module Strategy
-      module LocalCache
-        class MiddlewareTest < ActiveSupport::TestCase
-          def test_local_cache_cleared_on_close
-            key = "super awesome key"
-            assert_nil LocalCacheRegistry.cache_for key
-            middleware = Middleware.new("<3", key).new(->(env) {
-              assert LocalCacheRegistry.cache_for(key), "should have a cache"
-              [200, {}, []]
-            })
-            _, _, body = middleware.call({})
-            assert LocalCacheRegistry.cache_for(key), "should still have a cache"
-            body.each {}
-            assert LocalCacheRegistry.cache_for(key), "should still have a cache"
-            body.close
-            assert_nil LocalCacheRegistry.cache_for(key)
-          end
-
-          def test_local_cache_cleared_and_response_should_be_present_on_invalid_parameters_error
-            key = "super awesome key"
-            assert_nil LocalCacheRegistry.cache_for key
-            middleware = Middleware.new("<3", key).new(->(env) {
-              assert LocalCacheRegistry.cache_for(key), "should have a cache"
-              raise Rack::Utils::InvalidParameterError
-            })
-            response = middleware.call({})
-            assert response, "response should exist"
-            assert_nil LocalCacheRegistry.cache_for(key)
-          end
-
-          def test_local_cache_cleared_on_exception
-            key = "super awesome key"
-            assert_nil LocalCacheRegistry.cache_for key
-            middleware = Middleware.new("<3", key).new(->(env) {
-              assert LocalCacheRegistry.cache_for(key), "should have a cache"
-              raise
-            })
-            assert_raises(RuntimeError) { middleware.call({}) }
-            assert_nil LocalCacheRegistry.cache_for(key)
-          end
-
-          def test_local_cache_cleared_on_throw
-            key = "super awesome key"
-            assert_nil LocalCacheRegistry.cache_for key
-            middleware = Middleware.new("<3", key).new(->(env) {
-              assert LocalCacheRegistry.cache_for(key), "should have a cache"
-              throw :warden
-            })
-            assert_throws(:warden) { middleware.call({}) }
-            assert_nil LocalCacheRegistry.cache_for(key)
-          end
-        end
-      end
-    end
-  end
-end
-
-class CacheKeyTest < ActiveSupport::TestCase
-  def test_entry_legacy_optional_ivars
-    legacy = Class.new(ActiveSupport::Cache::Entry) do
-      def initialize(value, options = {})
-        @value = value
-        @expires_in = nil
-        @created_at = nil
-        super
-      end
-    end
-
-    entry = legacy.new "foo"
-    assert_equal "foo", entry.value
-  end
-
-  def test_expand_cache_key
-    assert_equal "1/2/true", ActiveSupport::Cache.expand_cache_key([1, "2", true])
-    assert_equal "name/1/2/true", ActiveSupport::Cache.expand_cache_key([1, "2", true], :name)
-  end
-
-  def test_expand_cache_key_with_rails_cache_id
-    with_env("RAILS_CACHE_ID" => "c99") do
-      assert_equal "c99/foo", ActiveSupport::Cache.expand_cache_key(:foo)
-      assert_equal "c99/foo", ActiveSupport::Cache.expand_cache_key([:foo])
-      assert_equal "c99/foo/bar", ActiveSupport::Cache.expand_cache_key([:foo, :bar])
-      assert_equal "nm/c99/foo", ActiveSupport::Cache.expand_cache_key(:foo, :nm)
-      assert_equal "nm/c99/foo", ActiveSupport::Cache.expand_cache_key([:foo], :nm)
-      assert_equal "nm/c99/foo/bar", ActiveSupport::Cache.expand_cache_key([:foo, :bar], :nm)
-    end
-  end
-
-  def test_expand_cache_key_with_rails_app_version
-    with_env("RAILS_APP_VERSION" => "rails3") do
-      assert_equal "rails3/foo", ActiveSupport::Cache.expand_cache_key(:foo)
-    end
-  end
-
-  def test_expand_cache_key_rails_cache_id_should_win_over_rails_app_version
-    with_env("RAILS_CACHE_ID" => "c99", "RAILS_APP_VERSION" => "rails3") do
-      assert_equal "c99/foo", ActiveSupport::Cache.expand_cache_key(:foo)
-    end
-  end
-
-  def test_expand_cache_key_respond_to_cache_key
-    key = "foo"
-    def key.cache_key
-      :foo_key
-    end
-    assert_equal "foo_key", ActiveSupport::Cache.expand_cache_key(key)
-  end
-
-  def test_expand_cache_key_array_with_something_that_responds_to_cache_key
-    key = "foo"
-    def key.cache_key
-      :foo_key
-    end
-    assert_equal "foo_key", ActiveSupport::Cache.expand_cache_key([key])
-  end
-
-  def test_expand_cache_key_of_nil
-    assert_equal "", ActiveSupport::Cache.expand_cache_key(nil)
-  end
-
-  def test_expand_cache_key_of_false
-    assert_equal "false", ActiveSupport::Cache.expand_cache_key(false)
-  end
-
-  def test_expand_cache_key_of_true
-    assert_equal "true", ActiveSupport::Cache.expand_cache_key(true)
-  end
-
-  def test_expand_cache_key_of_array_like_object
-    assert_equal "foo/bar/baz", ActiveSupport::Cache.expand_cache_key(%w{foo bar baz}.to_enum)
-  end
-
-  private
-
-    def with_env(kv)
-      old_values = {}
-      kv.each { |key, value| old_values[key], ENV[key] = ENV[key], value }
-      yield
-    ensure
-      old_values.each { |key, value| ENV[key] = value }
-    end
-end
-
-class CacheStoreSettingTest < ActiveSupport::TestCase
-  def test_memory_store_gets_created_if_no_arguments_passed_to_lookup_store_method
-    store = ActiveSupport::Cache.lookup_store
-    assert_kind_of(ActiveSupport::Cache::MemoryStore, store)
-  end
-
-  def test_memory_store
-    store = ActiveSupport::Cache.lookup_store :memory_store
-    assert_kind_of(ActiveSupport::Cache::MemoryStore, store)
-  end
-
-  def test_file_fragment_cache_store
-    store = ActiveSupport::Cache.lookup_store :file_store, "/path/to/cache/directory"
-    assert_kind_of(ActiveSupport::Cache::FileStore, store)
-    assert_equal "/path/to/cache/directory", store.cache_path
-  end
-
-  def test_mem_cache_fragment_cache_store
-    assert_called_with(Dalli::Client, :new, [%w[localhost], {}]) do
-      store = ActiveSupport::Cache.lookup_store :mem_cache_store, "localhost"
-      assert_kind_of(ActiveSupport::Cache::MemCacheStore, store)
-    end
-  end
-
-  def test_mem_cache_fragment_cache_store_with_given_mem_cache
-    mem_cache = Dalli::Client.new
-    assert_not_called(Dalli::Client, :new) do
-      store = ActiveSupport::Cache.lookup_store :mem_cache_store, mem_cache
-      assert_kind_of(ActiveSupport::Cache::MemCacheStore, store)
-    end
-  end
-
-  def test_mem_cache_fragment_cache_store_with_not_dalli_client
-    assert_not_called(Dalli::Client, :new) do
-      memcache = Object.new
-      assert_raises(ArgumentError) do
-        ActiveSupport::Cache.lookup_store :mem_cache_store, memcache
-      end
-    end
-  end
-
-  def test_mem_cache_fragment_cache_store_with_multiple_servers
-    assert_called_with(Dalli::Client, :new, [%w[localhost 192.168.1.1], {}]) do
-      store = ActiveSupport::Cache.lookup_store :mem_cache_store, "localhost", "192.168.1.1"
-      assert_kind_of(ActiveSupport::Cache::MemCacheStore, store)
-    end
-  end
-
-  def test_mem_cache_fragment_cache_store_with_options
-    assert_called_with(Dalli::Client, :new, [%w[localhost 192.168.1.1], { timeout: 10 }]) do
-      store = ActiveSupport::Cache.lookup_store :mem_cache_store, "localhost", "192.168.1.1", namespace: "foo", timeout: 10
-      assert_kind_of(ActiveSupport::Cache::MemCacheStore, store)
-      assert_equal "foo", store.options[:namespace]
-    end
-  end
-
-  def test_object_assigned_fragment_cache_store
-    store = ActiveSupport::Cache.lookup_store ActiveSupport::Cache::FileStore.new("/path/to/cache/directory")
-    assert_kind_of(ActiveSupport::Cache::FileStore, store)
-    assert_equal "/path/to/cache/directory", store.cache_path
-  end
-end
-
-class CacheStoreNamespaceTest < ActiveSupport::TestCase
-  def test_static_namespace
-    cache = ActiveSupport::Cache.lookup_store(:memory_store, namespace: "tester")
-    cache.write("foo", "bar")
-    assert_equal "bar", cache.read("foo")
-    assert_equal "bar", cache.instance_variable_get(:@data)["tester:foo"].value
-  end
-
-  def test_proc_namespace
-    test_val = "tester"
-    proc = lambda { test_val }
-    cache = ActiveSupport::Cache.lookup_store(:memory_store, namespace: proc)
-    cache.write("foo", "bar")
-    assert_equal "bar", cache.read("foo")
-    assert_equal "bar", cache.instance_variable_get(:@data)["tester:foo"].value
-  end
-
-  def test_delete_matched_key_start
-    cache = ActiveSupport::Cache.lookup_store(:memory_store, namespace: "tester")
-    cache.write("foo", "bar")
-    cache.write("fu", "baz")
-    cache.delete_matched(/^fo/)
-    assert !cache.exist?("foo")
-    assert cache.exist?("fu")
-  end
-
-  def test_delete_matched_key
-    cache = ActiveSupport::Cache.lookup_store(:memory_store, namespace: "foo")
-    cache.write("foo", "bar")
-    cache.write("fu", "baz")
-    cache.delete_matched(/OO/i)
-    assert !cache.exist?("foo")
-    assert cache.exist?("fu")
-  end
-end
-
-# Tests the base functionality that should be identical across all cache stores.
-module CacheStoreBehavior
-  def test_should_read_and_write_strings
-    assert @cache.write("foo", "bar")
-    assert_equal "bar", @cache.read("foo")
-  end
-
-  def test_should_overwrite
-    @cache.write("foo", "bar")
-    @cache.write("foo", "baz")
-    assert_equal "baz", @cache.read("foo")
-  end
-
-  def test_fetch_without_cache_miss
-    @cache.write("foo", "bar")
-    assert_not_called(@cache, :write) do
-      assert_equal "bar", @cache.fetch("foo") { "baz" }
-    end
-  end
-
-  def test_fetch_with_cache_miss
-    assert_called_with(@cache, :write, ["foo", "baz", @cache.options]) do
-      assert_equal "baz", @cache.fetch("foo") { "baz" }
-    end
-  end
-
-  def test_fetch_with_cache_miss_passes_key_to_block
-    cache_miss = false
-    assert_equal 3, @cache.fetch("foo") { |key| cache_miss = true; key.length }
-    assert cache_miss
-
-    cache_miss = false
-    assert_equal 3, @cache.fetch("foo") { |key| cache_miss = true; key.length }
-    assert !cache_miss
-  end
-
-  def test_fetch_with_forced_cache_miss
-    @cache.write("foo", "bar")
-    assert_not_called(@cache, :read) do
-      assert_called_with(@cache, :write, ["foo", "bar", @cache.options.merge(force: true)]) do
-        @cache.fetch("foo", force: true) { "bar" }
-      end
-    end
-  end
-
-  def test_fetch_with_cached_nil
-    @cache.write("foo", nil)
-    assert_not_called(@cache, :write) do
-      assert_nil @cache.fetch("foo") { "baz" }
-    end
-  end
-
-  def test_fetch_with_forced_cache_miss_with_block
-    @cache.write("foo", "bar")
-    assert_equal "foo_bar", @cache.fetch("foo", force: true) { "foo_bar" }
-  end
-
-  def test_fetch_with_forced_cache_miss_without_block
-    @cache.write("foo", "bar")
-    assert_raises(ArgumentError) do
-      @cache.fetch("foo", force: true)
-    end
-
-    assert_equal "bar", @cache.read("foo")
-  end
-
-  def test_should_read_and_write_hash
-    assert @cache.write("foo", a: "b")
-    assert_equal({ a: "b" }, @cache.read("foo"))
-  end
-
-  def test_should_read_and_write_integer
-    assert @cache.write("foo", 1)
-    assert_equal 1, @cache.read("foo")
-  end
-
-  def test_should_read_and_write_nil
-    assert @cache.write("foo", nil)
-    assert_nil @cache.read("foo")
-  end
-
-  def test_should_read_and_write_false
-    assert @cache.write("foo", false)
-    assert_equal false, @cache.read("foo")
-  end
-
-  def test_read_multi
-    @cache.write("foo", "bar")
-    @cache.write("fu", "baz")
-    @cache.write("fud", "biz")
-    assert_equal({ "foo" => "bar", "fu" => "baz" }, @cache.read_multi("foo", "fu"))
-  end
-
-  def test_read_multi_with_expires
-    time = Time.now
-    @cache.write("foo", "bar", expires_in: 10)
-    @cache.write("fu", "baz")
-    @cache.write("fud", "biz")
-    Time.stub(:now, time + 11) do
-      assert_equal({ "fu" => "baz" }, @cache.read_multi("foo", "fu"))
-    end
-  end
-
-  def test_fetch_multi
-    @cache.write("foo", "bar")
-    @cache.write("fud", "biz")
-
-    values = @cache.fetch_multi("foo", "fu", "fud") { |value| value * 2 }
-
-    assert_equal({ "foo" => "bar", "fu" => "fufu", "fud" => "biz" }, values)
-    assert_equal("fufu", @cache.read("fu"))
-  end
-
-  def test_multi_with_objects
-    cache_struct = Struct.new(:cache_key, :title)
-    foo = cache_struct.new("foo", "FOO!")
-    bar = cache_struct.new("bar")
-
-    @cache.write("bar", "BAM!")
-
-    values = @cache.fetch_multi(foo, bar) { |object| object.title }
-
-    assert_equal({ foo => "FOO!", bar => "BAM!" }, values)
-  end
-
-  def test_fetch_multi_without_block
-    assert_raises(ArgumentError) do
-      @cache.fetch_multi("foo")
-    end
-  end
-
-  def test_read_and_write_compressed_small_data
-    @cache.write("foo", "bar", compress: true)
-    assert_equal "bar", @cache.read("foo")
-  end
-
-  def test_read_and_write_compressed_large_data
-    @cache.write("foo", "bar", compress: true, compress_threshold: 2)
-    assert_equal "bar", @cache.read("foo")
-  end
-
-  def test_read_and_write_compressed_nil
-    @cache.write("foo", nil, compress: true)
-    assert_nil @cache.read("foo")
-  end
-
-  def test_cache_key
-    obj = Object.new
-    def obj.cache_key
-      :foo
-    end
-    @cache.write(obj, "bar")
-    assert_equal "bar", @cache.read("foo")
-  end
-
-  def test_param_as_cache_key
-    obj = Object.new
-    def obj.to_param
-      "foo"
-    end
-    @cache.write(obj, "bar")
-    assert_equal "bar", @cache.read("foo")
-  end
-
-  def test_array_as_cache_key
-    @cache.write([:fu, "foo"], "bar")
-    assert_equal "bar", @cache.read("fu/foo")
-  end
-
-  def test_hash_as_cache_key
-    @cache.write({ foo: 1, fu: 2 }, "bar")
-    assert_equal "bar", @cache.read("foo=1/fu=2")
-  end
-
-  def test_keys_are_case_sensitive
-    @cache.write("foo", "bar")
-    assert_nil @cache.read("FOO")
-  end
-
-  def test_exist
-    @cache.write("foo", "bar")
-    assert_equal true, @cache.exist?("foo")
-    assert_equal false, @cache.exist?("bar")
-  end
-
-  def test_nil_exist
-    @cache.write("foo", nil)
-    assert @cache.exist?("foo")
-  end
-
-  def test_delete
-    @cache.write("foo", "bar")
-    assert @cache.exist?("foo")
-    assert @cache.delete("foo")
-    assert !@cache.exist?("foo")
-  end
-
-  def test_original_store_objects_should_not_be_immutable
-    bar = "bar"
-    @cache.write("foo", bar)
-    assert_nothing_raised { bar.gsub!(/.*/, "baz") }
-  end
-
-  def test_expires_in
-    time = Time.local(2008, 4, 24)
-
-    Time.stub(:now, time) do
-      @cache.write("foo", "bar")
-      assert_equal "bar", @cache.read("foo")
-    end
-
-    Time.stub(:now, time + 30) do
-      assert_equal "bar", @cache.read("foo")
-    end
-
-    Time.stub(:now, time + 61) do
-      assert_nil @cache.read("foo")
-    end
-  end
-
-  def test_race_condition_protection_skipped_if_not_defined
-    @cache.write("foo", "bar")
-    time = @cache.send(:read_entry, @cache.send(:normalize_key, "foo", {}), {}).expires_at
-
-    Time.stub(:now, Time.at(time)) do
-      result = @cache.fetch("foo") do
-        assert_nil @cache.read("foo")
-        "baz"
-      end
-      assert_equal "baz", result
-    end
-  end
-
-  def test_race_condition_protection_is_limited
-    time = Time.now
-    @cache.write("foo", "bar", expires_in: 60)
-    Time.stub(:now, time + 71) do
-      result = @cache.fetch("foo", race_condition_ttl: 10) do
-        assert_nil @cache.read("foo")
-        "baz"
-      end
-      assert_equal "baz", result
-    end
-  end
-
-  def test_race_condition_protection_is_safe
-    time = Time.now
-    @cache.write("foo", "bar", expires_in: 60)
-    Time.stub(:now, time + 61) do
-      begin
-        @cache.fetch("foo", race_condition_ttl: 10) do
-          assert_equal "bar", @cache.read("foo")
-          raise ArgumentError.new
-        end
-      rescue ArgumentError
-      end
-      assert_equal "bar", @cache.read("foo")
-    end
-    Time.stub(:now, time + 91) do
-      assert_nil @cache.read("foo")
-    end
-  end
-
-  def test_race_condition_protection
-    time = Time.now
-    @cache.write("foo", "bar", expires_in: 60)
-    Time.stub(:now, time + 61) do
-      result = @cache.fetch("foo", race_condition_ttl: 10) do
-        assert_equal "bar", @cache.read("foo")
-        "baz"
-      end
-      assert_equal "baz", result
-    end
-  end
-
-  def test_crazy_key_characters
-    crazy_key = "#/:*(<+=> )&$%@?;'\"\'`~-"
-    assert @cache.write(crazy_key, "1", raw: true)
-    assert_equal "1", @cache.read(crazy_key)
-    assert_equal "1", @cache.fetch(crazy_key)
-    assert @cache.delete(crazy_key)
-    assert_equal "2", @cache.fetch(crazy_key, raw: true) { "2" }
-    assert_equal 3, @cache.increment(crazy_key)
-    assert_equal 2, @cache.decrement(crazy_key)
-  end
-
-  def test_really_long_keys
-    key = ""
-    900.times { key << "x" }
-    assert @cache.write(key, "bar")
-    assert_equal "bar", @cache.read(key)
-    assert_equal "bar", @cache.fetch(key)
-    assert_nil @cache.read("#{key}x")
-    assert_equal({ key => "bar" }, @cache.read_multi(key))
-    assert @cache.delete(key)
-  end
-
-  def test_cache_hit_instrumentation
-    key = "test_key"
-    @events = []
-    ActiveSupport::Notifications.subscribe "cache_read.active_support" do |*args|
-      @events << ActiveSupport::Notifications::Event.new(*args)
-    end
-    assert @cache.write(key, "1", raw: true)
-    assert @cache.fetch(key) {}
-    assert_equal 1, @events.length
-    assert_equal "cache_read.active_support", @events[0].name
-    assert_equal :fetch, @events[0].payload[:super_operation]
-    assert @events[0].payload[:hit]
-  ensure
-    ActiveSupport::Notifications.unsubscribe "cache_read.active_support"
-  end
-
-  def test_cache_miss_instrumentation
-    @events = []
-    ActiveSupport::Notifications.subscribe(/^cache_(.*)\.active_support$/) do |*args|
-      @events << ActiveSupport::Notifications::Event.new(*args)
-    end
-    assert_not @cache.fetch("bad_key") {}
-    assert_equal 3, @events.length
-    assert_equal "cache_read.active_support", @events[0].name
-    assert_equal "cache_generate.active_support", @events[1].name
-    assert_equal "cache_write.active_support", @events[2].name
-    assert_equal :fetch, @events[0].payload[:super_operation]
-    assert_not @events[0].payload[:hit]
-  ensure
-    ActiveSupport::Notifications.unsubscribe "cache_read.active_support"
-  end
-end
-
-# https://rails.lighthouseapp.com/projects/8994/tickets/6225-memcachestore-cant-deal-with-umlauts-and-special-characters
-# The error is caused by character encodings that can't be compared with ASCII-8BIT regular expressions and by special
-# characters like the umlaut in UTF-8.
-module EncodedKeyCacheBehavior
-  Encoding.list.each do |encoding|
-    define_method "test_#{encoding.name.underscore}_encoded_values" do
-      key = "foo".force_encoding(encoding)
-      assert @cache.write(key, "1", raw: true)
-      assert_equal "1", @cache.read(key)
-      assert_equal "1", @cache.fetch(key)
-      assert @cache.delete(key)
-      assert_equal "2", @cache.fetch(key, raw: true) { "2" }
-      assert_equal 3, @cache.increment(key)
-      assert_equal 2, @cache.decrement(key)
-    end
-  end
-
-  def test_common_utf8_values
-    key = "\xC3\xBCmlaut".force_encoding(Encoding::UTF_8)
-    assert @cache.write(key, "1", raw: true)
-    assert_equal "1", @cache.read(key)
-    assert_equal "1", @cache.fetch(key)
-    assert @cache.delete(key)
-    assert_equal "2", @cache.fetch(key, raw: true) { "2" }
-    assert_equal 3, @cache.increment(key)
-    assert_equal 2, @cache.decrement(key)
-  end
-
-  def test_retains_encoding
-    key = "\xC3\xBCmlaut".force_encoding(Encoding::UTF_8)
-    assert @cache.write(key, "1", raw: true)
-    assert_equal Encoding::UTF_8, key.encoding
-  end
-end
-
-module CacheDeleteMatchedBehavior
-  def test_delete_matched
-    @cache.write("foo", "bar")
-    @cache.write("fu", "baz")
-    @cache.write("foo/bar", "baz")
-    @cache.write("fu/baz", "bar")
-    @cache.delete_matched(/oo/)
-    assert !@cache.exist?("foo")
-    assert @cache.exist?("fu")
-    assert !@cache.exist?("foo/bar")
-    assert @cache.exist?("fu/baz")
-  end
-end
-
-module CacheIncrementDecrementBehavior
-  def test_increment
-    @cache.write("foo", 1, raw: true)
-    assert_equal 1, @cache.read("foo").to_i
-    assert_equal 2, @cache.increment("foo")
-    assert_equal 2, @cache.read("foo").to_i
-    assert_equal 3, @cache.increment("foo")
-    assert_equal 3, @cache.read("foo").to_i
-    assert_nil @cache.increment("bar")
-  end
-
-  def test_decrement
-    @cache.write("foo", 3, raw: true)
-    assert_equal 3, @cache.read("foo").to_i
-    assert_equal 2, @cache.decrement("foo")
-    assert_equal 2, @cache.read("foo").to_i
-    assert_equal 1, @cache.decrement("foo")
-    assert_equal 1, @cache.read("foo").to_i
-    assert_nil @cache.decrement("bar")
-  end
-end
-
-module LocalCacheBehavior
-  def test_local_writes_are_persistent_on_the_remote_cache
-    retval = @cache.with_local_cache do
-      @cache.write("foo", "bar")
-    end
-    assert retval
-    assert_equal "bar", @cache.read("foo")
-  end
-
-  def test_clear_also_clears_local_cache
-    @cache.with_local_cache do
-      @cache.write("foo", "bar")
-      @cache.clear
-      assert_nil @cache.read("foo")
-    end
-
-    assert_nil @cache.read("foo")
-  end
-
-  def test_local_cache_of_write
-    @cache.with_local_cache do
-      @cache.write("foo", "bar")
-      @peek.delete("foo")
-      assert_equal "bar", @cache.read("foo")
-    end
-  end
-
-  def test_local_cache_of_read
-    @cache.write("foo", "bar")
-    @cache.with_local_cache do
-      assert_equal "bar", @cache.read("foo")
-    end
-  end
-
-  def test_local_cache_of_read_nil
-    @cache.with_local_cache do
-      assert_nil @cache.read("foo")
-      @cache.send(:bypass_local_cache) { @cache.write "foo", "bar" }
-      assert_nil @cache.read("foo")
-    end
-  end
-
-  def test_local_cache_fetch
-    @cache.with_local_cache do
-      @cache.send(:local_cache).write "foo", "bar"
-      assert_equal "bar", @cache.send(:local_cache).fetch("foo")
-    end
-  end
-
-  def test_local_cache_of_write_nil
-    @cache.with_local_cache do
-      assert @cache.write("foo", nil)
-      assert_nil @cache.read("foo")
-      @peek.write("foo", "bar")
-      assert_nil @cache.read("foo")
-    end
-  end
-
-  def test_local_cache_of_write_with_unless_exist
-    @cache.with_local_cache do
-      @cache.write("foo", "bar")
-      @cache.write("foo", "baz", unless_exist: true)
-      assert_equal @peek.read("foo"), @cache.read("foo")
-    end
-  end
-
-  def test_local_cache_of_delete
-    @cache.with_local_cache do
-      @cache.write("foo", "bar")
-      @cache.delete("foo")
-      assert_nil @cache.read("foo")
-    end
-  end
-
-  def test_local_cache_of_exist
-    @cache.with_local_cache do
-      @cache.write("foo", "bar")
-      @peek.delete("foo")
-      assert @cache.exist?("foo")
-    end
-  end
-
-  def test_local_cache_of_increment
-    @cache.with_local_cache do
-      @cache.write("foo", 1, raw: true)
-      @peek.write("foo", 2, raw: true)
-      @cache.increment("foo")
-      assert_equal 3, @cache.read("foo")
-    end
-  end
-
-  def test_local_cache_of_decrement
-    @cache.with_local_cache do
-      @cache.write("foo", 1, raw: true)
-      @peek.write("foo", 3, raw: true)
-      @cache.decrement("foo")
-      assert_equal 2, @cache.read("foo")
-    end
-  end
-
-  def test_middleware
-    app = lambda { |env|
-      result = @cache.write("foo", "bar")
-      assert_equal "bar", @cache.read("foo") # make sure 'foo' was written
-      assert result
-      [200, {}, []]
-    }
-    app = @cache.middleware.new(app)
-    app.call({})
-  end
-end
-
-module AutoloadingCacheBehavior
-  include DependenciesTestHelpers
-  def test_simple_autoloading
-    with_autoloading_fixtures do
-      @cache.write("foo", EM.new)
-    end
-
-    remove_constants(:EM)
-    ActiveSupport::Dependencies.clear
-
-    with_autoloading_fixtures do
-      assert_kind_of EM, @cache.read("foo")
-    end
-
-    remove_constants(:EM)
-    ActiveSupport::Dependencies.clear
-  end
-
-  def test_two_classes_autoloading
-    with_autoloading_fixtures do
-      @cache.write("foo", [EM.new, ClassFolder.new])
-    end
-
-    remove_constants(:EM, :ClassFolder)
-    ActiveSupport::Dependencies.clear
-
-    with_autoloading_fixtures do
-      loaded = @cache.read("foo")
-      assert_kind_of Array, loaded
-      assert_equal 2, loaded.size
-      assert_kind_of EM, loaded[0]
-      assert_kind_of ClassFolder, loaded[1]
-    end
-
-    remove_constants(:EM, :ClassFolder)
-    ActiveSupport::Dependencies.clear
-  end
-end
-
-class FileStoreTest < ActiveSupport::TestCase
-  def setup
-    Dir.mkdir(cache_dir) unless File.exist?(cache_dir)
-    @cache = ActiveSupport::Cache.lookup_store(:file_store, cache_dir, expires_in: 60)
-    @peek = ActiveSupport::Cache.lookup_store(:file_store, cache_dir, expires_in: 60)
-    @cache_with_pathname = ActiveSupport::Cache.lookup_store(:file_store, Pathname.new(cache_dir), expires_in: 60)
-
-    @buffer = StringIO.new
-    @cache.logger = ActiveSupport::Logger.new(@buffer)
-  end
-
-  def teardown
-    FileUtils.rm_r(cache_dir)
-  rescue Errno::ENOENT
-  end
-
-  def cache_dir
-    File.join(Dir.pwd, "tmp_cache")
-  end
-
-  include CacheStoreBehavior
-  include LocalCacheBehavior
-  include CacheDeleteMatchedBehavior
-  include CacheIncrementDecrementBehavior
-  include AutoloadingCacheBehavior
-
-  def test_clear
-    gitkeep = File.join(cache_dir, ".gitkeep")
-    keep = File.join(cache_dir, ".keep")
-    FileUtils.touch([gitkeep, keep])
-    @cache.clear
-    assert File.exist?(gitkeep)
-    assert File.exist?(keep)
-  end
-
-  def test_clear_without_cache_dir
-    FileUtils.rm_r(cache_dir)
-    @cache.clear
-  end
-
-  def test_long_uri_encoded_keys
-    @cache.write("%" * 870, 1)
-    assert_equal 1, @cache.read("%" * 870)
-  end
-
-  def test_key_transformation
-    key = @cache.send(:normalize_key, "views/index?id=1", {})
-    assert_equal "views/index?id=1", @cache.send(:file_path_key, key)
-  end
-
-  def test_key_transformation_with_pathname
-    FileUtils.touch(File.join(cache_dir, "foo"))
-    key = @cache_with_pathname.send(:normalize_key, "views/index?id=1", {})
-    assert_equal "views/index?id=1", @cache_with_pathname.send(:file_path_key, key)
-  end
-
-  # Test that generated cache keys are short enough to have Tempfile stuff added to them and
-  # remain valid
-  def test_filename_max_size
-    key = "#{'A' * ActiveSupport::Cache::FileStore::FILENAME_MAX_SIZE}"
-    path = @cache.send(:normalize_key, key, {})
-    Dir::Tmpname.create(path) do |tmpname, n, opts|
-      assert File.basename(tmpname + ".lock").length <= 255, "Temp filename too long: #{File.basename(tmpname + '.lock').length}"
-    end
-  end
-
-  # Because file systems have a maximum filename size, filenames > max size should be split in to directories
-  # If filename is 'AAAAB', where max size is 4, the returned path should be AAAA/B
-  def test_key_transformation_max_filename_size
-    key = "#{'A' * ActiveSupport::Cache::FileStore::FILENAME_MAX_SIZE}B"
-    path = @cache.send(:normalize_key, key, {})
-    assert path.split("/").all? { |dir_name| dir_name.size <= ActiveSupport::Cache::FileStore::FILENAME_MAX_SIZE }
-    assert_equal "B", File.basename(path)
-  end
-
-  # If nothing has been stored in the cache, there is a chance the cache directory does not yet exist
-  # Ensure delete_matched gracefully handles this case
-  def test_delete_matched_when_cache_directory_does_not_exist
-    assert_nothing_raised do
-      ActiveSupport::Cache::FileStore.new("/test/cache/directory").delete_matched(/does_not_exist/)
-    end
-  end
-
-  def test_delete_does_not_delete_empty_parent_dir
-    sub_cache_dir = File.join(cache_dir, "subdir/")
-    sub_cache_store = ActiveSupport::Cache::FileStore.new(sub_cache_dir)
-    assert_nothing_raised do
-      assert sub_cache_store.write("foo", "bar")
-      assert sub_cache_store.delete("foo")
-    end
-    assert File.exist?(cache_dir), "Parent of top level cache dir was deleted!"
-    assert File.exist?(sub_cache_dir), "Top level cache dir was deleted!"
-    assert Dir.entries(sub_cache_dir).reject { |f| ActiveSupport::Cache::FileStore::EXCLUDED_DIRS.include?(f) }.empty?
-  end
-
-  def test_log_exception_when_cache_read_fails
-    File.stub(:exist?, -> { raise StandardError.new("failed") }) do
-      @cache.send(:read_entry, "winston", {})
-      assert @buffer.string.present?
-    end
-  end
-
-  def test_cleanup_removes_all_expired_entries
-    time = Time.now
-    @cache.write("foo", "bar", expires_in: 10)
-    @cache.write("baz", "qux")
-    @cache.write("quux", "corge", expires_in: 20)
-    Time.stub(:now, time + 15) do
-      @cache.cleanup
-      assert_not @cache.exist?("foo")
-      assert @cache.exist?("baz")
-      assert @cache.exist?("quux")
-    end
-  end
-
-  def test_write_with_unless_exist
-    assert_equal true, @cache.write(1, "aaaaaaaaaa")
-    assert_equal false, @cache.write(1, "aaaaaaaaaa", unless_exist: true)
-    @cache.write(1, nil)
-    assert_equal false, @cache.write(1, "aaaaaaaaaa", unless_exist: true)
-  end
-end
-
-class MemoryStoreTest < ActiveSupport::TestCase
-  def setup
-    @record_size = ActiveSupport::Cache.lookup_store(:memory_store).send(:cached_size, 1, ActiveSupport::Cache::Entry.new("aaaaaaaaaa"))
-    @cache = ActiveSupport::Cache.lookup_store(:memory_store, expires_in: 60, size: @record_size * 10 + 1)
-  end
-
-  include CacheStoreBehavior
-  include CacheDeleteMatchedBehavior
-  include CacheIncrementDecrementBehavior
-
-  def test_prune_size
-    @cache.write(1, "aaaaaaaaaa") && sleep(0.001)
-    @cache.write(2, "bbbbbbbbbb") && sleep(0.001)
-    @cache.write(3, "cccccccccc") && sleep(0.001)
-    @cache.write(4, "dddddddddd") && sleep(0.001)
-    @cache.write(5, "eeeeeeeeee") && sleep(0.001)
-    @cache.read(2) && sleep(0.001)
-    @cache.read(4)
-    @cache.prune(@record_size * 3)
-    assert @cache.exist?(5)
-    assert @cache.exist?(4)
-    assert !@cache.exist?(3), "no entry"
-    assert @cache.exist?(2)
-    assert !@cache.exist?(1), "no entry"
-  end
-
-  def test_prune_size_on_write
-    @cache.write(1, "aaaaaaaaaa") && sleep(0.001)
-    @cache.write(2, "bbbbbbbbbb") && sleep(0.001)
-    @cache.write(3, "cccccccccc") && sleep(0.001)
-    @cache.write(4, "dddddddddd") && sleep(0.001)
-    @cache.write(5, "eeeeeeeeee") && sleep(0.001)
-    @cache.write(6, "ffffffffff") && sleep(0.001)
-    @cache.write(7, "gggggggggg") && sleep(0.001)
-    @cache.write(8, "hhhhhhhhhh") && sleep(0.001)
-    @cache.write(9, "iiiiiiiiii") && sleep(0.001)
-    @cache.write(10, "kkkkkkkkkk") && sleep(0.001)
-    @cache.read(2) && sleep(0.001)
-    @cache.read(4) && sleep(0.001)
-    @cache.write(11, "llllllllll")
-    assert @cache.exist?(11)
-    assert @cache.exist?(10)
-    assert @cache.exist?(9)
-    assert @cache.exist?(8)
-    assert @cache.exist?(7)
-    assert !@cache.exist?(6), "no entry"
-    assert !@cache.exist?(5), "no entry"
-    assert @cache.exist?(4)
-    assert !@cache.exist?(3), "no entry"
-    assert @cache.exist?(2)
-    assert !@cache.exist?(1), "no entry"
-  end
-
-  def test_prune_size_on_write_based_on_key_length
-    @cache.write(1, "aaaaaaaaaa") && sleep(0.001)
-    @cache.write(2, "bbbbbbbbbb") && sleep(0.001)
-    @cache.write(3, "cccccccccc") && sleep(0.001)
-    @cache.write(4, "dddddddddd") && sleep(0.001)
-    @cache.write(5, "eeeeeeeeee") && sleep(0.001)
-    @cache.write(6, "ffffffffff") && sleep(0.001)
-    @cache.write(7, "gggggggggg") && sleep(0.001)
-    @cache.write(8, "hhhhhhhhhh") && sleep(0.001)
-    @cache.write(9, "iiiiiiiiii") && sleep(0.001)
-    long_key = "*" * 2 * @record_size
-    @cache.write(long_key, "llllllllll")
-    assert @cache.exist?(long_key)
-    assert @cache.exist?(9)
-    assert @cache.exist?(8)
-    assert @cache.exist?(7)
-    assert @cache.exist?(6)
-    assert !@cache.exist?(5), "no entry"
-    assert !@cache.exist?(4), "no entry"
-    assert !@cache.exist?(3), "no entry"
-    assert !@cache.exist?(2), "no entry"
-    assert !@cache.exist?(1), "no entry"
-  end
-
-  def test_pruning_is_capped_at_a_max_time
-    def @cache.delete_entry(*args)
-      sleep(0.01)
-      super
-    end
-    @cache.write(1, "aaaaaaaaaa") && sleep(0.001)
-    @cache.write(2, "bbbbbbbbbb") && sleep(0.001)
-    @cache.write(3, "cccccccccc") && sleep(0.001)
-    @cache.write(4, "dddddddddd") && sleep(0.001)
-    @cache.write(5, "eeeeeeeeee") && sleep(0.001)
-    @cache.prune(30, 0.001)
-    assert @cache.exist?(5)
-    assert @cache.exist?(4)
-    assert @cache.exist?(3)
-    assert @cache.exist?(2)
-    assert !@cache.exist?(1)
-  end
-
-  def test_write_with_unless_exist
-    assert_equal true, @cache.write(1, "aaaaaaaaaa")
-    assert_equal false, @cache.write(1, "aaaaaaaaaa", unless_exist: true)
-    @cache.write(1, nil)
-    assert_equal false, @cache.write(1, "aaaaaaaaaa", unless_exist: true)
-  end
-end
-
-class MemCacheStoreTest < ActiveSupport::TestCase
-  require "dalli"
-
-  begin
-    ss = Dalli::Client.new("localhost:11211").stats
-    raise Dalli::DalliError unless ss["localhost:11211"]
-
-    MEMCACHE_UP = true
-  rescue Dalli::DalliError
-    $stderr.puts "Skipping memcached tests. Start memcached and try again."
-    MEMCACHE_UP = false
-  end
-
-  def setup
-    skip "memcache server is not up" unless MEMCACHE_UP
-
-    @cache = ActiveSupport::Cache.lookup_store(:mem_cache_store, expires_in: 60)
-    @peek = ActiveSupport::Cache.lookup_store(:mem_cache_store)
-    @data = @cache.instance_variable_get(:@data)
-    @cache.clear
-    @cache.silence!
-    @cache.logger = ActiveSupport::Logger.new("/dev/null")
-  end
-
-  include CacheStoreBehavior
-  include LocalCacheBehavior
-  include CacheIncrementDecrementBehavior
-  include EncodedKeyCacheBehavior
-  include AutoloadingCacheBehavior
-
-  def test_raw_values
-    cache = ActiveSupport::Cache.lookup_store(:mem_cache_store, raw: true)
-    cache.clear
-    cache.write("foo", 2)
-    assert_equal "2", cache.read("foo")
-  end
-
-  def test_raw_values_with_marshal
-    cache = ActiveSupport::Cache.lookup_store(:mem_cache_store, raw: true)
-    cache.clear
-    cache.write("foo", Marshal.dump([]))
-    assert_equal [], cache.read("foo")
-  end
-
-  def test_local_cache_raw_values
-    cache = ActiveSupport::Cache.lookup_store(:mem_cache_store, raw: true)
-    cache.clear
-    cache.with_local_cache do
-      cache.write("foo", 2)
-      assert_equal "2", cache.read("foo")
-    end
-  end
-
-  def test_local_cache_raw_values_with_marshal
-    cache = ActiveSupport::Cache.lookup_store(:mem_cache_store, raw: true)
-    cache.clear
-    cache.with_local_cache do
-      cache.write("foo", Marshal.dump([]))
-      assert_equal [], cache.read("foo")
-    end
-  end
-
-  def test_read_should_return_a_different_object_id_each_time_it_is_called
-    @cache.write("foo", "bar")
-    value = @cache.read("foo")
-    assert_not_equal value.object_id, @cache.read("foo").object_id
-    value << "bingo"
-    assert_not_equal value, @cache.read("foo")
-  end
-end
-
-class NullStoreTest < ActiveSupport::TestCase
-  def setup
-    @cache = ActiveSupport::Cache.lookup_store(:null_store)
-  end
-
-  def test_clear
-    @cache.clear
-  end
-
-  def test_cleanup
-    @cache.cleanup
-  end
-
-  def test_write
-    assert_equal true, @cache.write("name", "value")
-  end
-
-  def test_read
-    @cache.write("name", "value")
-    assert_nil @cache.read("name")
-  end
-
-  def test_delete
-    @cache.write("name", "value")
-    assert_equal false, @cache.delete("name")
-  end
-
-  def test_increment
-    @cache.write("name", 1, raw: true)
-    assert_nil @cache.increment("name")
-  end
-
-  def test_decrement
-    @cache.write("name", 1, raw: true)
-    assert_nil @cache.increment("name")
-  end
-
-  def test_delete_matched
-    @cache.write("name", "value")
-    @cache.delete_matched(/name/)
-  end
-
-  def test_local_store_strategy
-    @cache.with_local_cache do
-      @cache.write("name", "value")
-      assert_equal "value", @cache.read("name")
-      @cache.delete("name")
-      assert_nil @cache.read("name")
-      @cache.write("name", "value")
-    end
-    assert_nil @cache.read("name")
-  end
-end
-
-class CacheStoreLoggerTest < ActiveSupport::TestCase
-  def setup
-    @cache = ActiveSupport::Cache.lookup_store(:memory_store)
-
-    @buffer = StringIO.new
-    @cache.logger = ActiveSupport::Logger.new(@buffer)
-  end
-
-  def test_logging
-    @cache.fetch("foo") { "bar" }
-    assert @buffer.string.present?
-  end
-
-  def test_log_with_string_namespace
-    @cache.fetch("foo", namespace: "string_namespace") { "bar" }
-    assert_match %r{string_namespace:foo}, @buffer.string
-  end
-
-  def test_log_with_proc_namespace
-    proc = Proc.new do
-      "proc_namespace"
-    end
-    @cache.fetch("foo", namespace: proc) { "bar" }
-    assert_match %r{proc_namespace:foo}, @buffer.string
-  end
-
-  def test_mute_logging
-    @cache.mute { @cache.fetch("foo") { "bar" } }
-    assert @buffer.string.blank?
-  end
-end
-
-class CacheEntryTest < ActiveSupport::TestCase
-  def test_expired
-    entry = ActiveSupport::Cache::Entry.new("value")
-    assert !entry.expired?, "entry not expired"
-    entry = ActiveSupport::Cache::Entry.new("value", expires_in: 60)
-    assert !entry.expired?, "entry not expired"
-    Time.stub(:now, Time.now + 61) do
-      assert entry.expired?, "entry is expired"
-    end
-  end
-
-  def test_compress_values
-    value = "value" * 100
-    entry = ActiveSupport::Cache::Entry.new(value, compress: true, compress_threshold: 1)
-    assert_equal value, entry.value
-    assert(value.bytesize > entry.size, "value is compressed")
-  end
-
-  def test_non_compress_values
-    value = "value" * 100
-    entry = ActiveSupport::Cache::Entry.new(value)
-    assert_equal value, entry.value
-    assert_equal value.bytesize, entry.size
-  end
-end
diff --git a/activesupport/test/core_ext/class/attribute_test.rb b/activesupport/test/core_ext/class/attribute_test.rb
index 5a9ec78cc1..f16043c612 100644
--- a/activesupport/test/core_ext/class/attribute_test.rb
+++ b/activesupport/test/core_ext/class/attribute_test.rb
@@ -3,7 +3,11 @@ require "active_support/core_ext/class/attribute"
 
 class ClassAttributeTest < ActiveSupport::TestCase
   def setup
-    @klass = Class.new { class_attribute :setting }
+    @klass = Class.new do
+      class_attribute :setting
+      class_attribute :timeout, default: 5
+    end
+
     @sub = Class.new(@klass)
   end
 
@@ -12,6 +16,10 @@ class ClassAttributeTest < ActiveSupport::TestCase
     assert_nil @sub.setting
   end
 
+  test "custom default" do
+    assert_equal 5, @klass.timeout
+  end
+
   test "inheritable" do
     @klass.setting = 1
     assert_equal 1, @sub.setting
diff --git a/activesupport/test/core_ext/date_time_ext_test.rb b/activesupport/test/core_ext/date_time_ext_test.rb
index be7c14e9b4..276fa2bfd3 100644
--- a/activesupport/test/core_ext/date_time_ext_test.rb
+++ b/activesupport/test/core_ext/date_time_ext_test.rb
@@ -28,6 +28,28 @@ class DateTimeExtCalculationsTest < ActiveSupport::TestCase
     end
   end
 
+  def test_next_occur
+    datetime = DateTime.new(2016, 9, 24, 0, 0) # saturday
+    assert_equal datetime.next_occurring(:monday), datetime.since(2.days)
+    assert_equal datetime.next_occurring(:tuesday), datetime.since(3.days)
+    assert_equal datetime.next_occurring(:wednesday), datetime.since(4.days)
+    assert_equal datetime.next_occurring(:thursday), datetime.since(5.days)
+    assert_equal datetime.next_occurring(:friday), datetime.since(6.days)
+    assert_equal datetime.next_occurring(:saturday), datetime.since(1.week)
+    assert_equal datetime.next_occurring(:sunday), datetime.since(1.day)
+  end
+
+  def test_prev_occur
+    datetime = DateTime.new(2016, 9, 24, 0, 0) # saturday
+    assert_equal datetime.prev_occurring(:monday), datetime.ago(5.days)
+    assert_equal datetime.prev_occurring(:tuesday), datetime.ago(4.days)
+    assert_equal datetime.prev_occurring(:wednesday), datetime.ago(3.days)
+    assert_equal datetime.prev_occurring(:thursday), datetime.ago(2.days)
+    assert_equal datetime.prev_occurring(:friday), datetime.ago(1.day)
+    assert_equal datetime.prev_occurring(:saturday), datetime.ago(1.week)
+    assert_equal datetime.prev_occurring(:sunday), datetime.ago(6.days)
+  end
+
   def test_readable_inspect
     datetime = DateTime.new(2005, 2, 21, 14, 30, 0)
     assert_equal "Mon, 21 Feb 2005 14:30:00 +0000", datetime.readable_inspect
diff --git a/activesupport/test/core_ext/duration_test.rb b/activesupport/test/core_ext/duration_test.rb
index 1648a9b270..3108f24f21 100644
--- a/activesupport/test/core_ext/duration_test.rb
+++ b/activesupport/test/core_ext/duration_test.rb
@@ -337,6 +337,13 @@ class DurationTest < ActiveSupport::TestCase
     assert_equal "no implicit conversion of String into ActiveSupport::Duration::Scalar", exception.message
   end
 
+  def test_scalar_plus_parts
+    scalar = ActiveSupport::Duration::Scalar.new(10)
+
+    assert_equal({ days: 1, seconds: 10 }, (scalar + 1.day).parts)
+    assert_equal({ days: -1, seconds: 10 }, (scalar + -1.day).parts)
+  end
+
   def test_scalar_minus
     scalar = ActiveSupport::Duration::Scalar.new(10)
 
@@ -349,6 +356,9 @@ class DurationTest < ActiveSupport::TestCase
     assert_equal 5, scalar - 5.seconds
     assert_instance_of ActiveSupport::Duration, scalar - 5.seconds
 
+    assert_equal({ days: -1, seconds: 10 }, (scalar - 1.day).parts)
+    assert_equal({ days: 1, seconds: 10 }, (scalar - -1.day).parts)
+
     exception = assert_raises(TypeError) do
       scalar - "foo"
     end
@@ -356,6 +366,13 @@ class DurationTest < ActiveSupport::TestCase
     assert_equal "no implicit conversion of String into ActiveSupport::Duration::Scalar", exception.message
   end
 
+  def test_scalar_minus_parts
+    scalar = ActiveSupport::Duration::Scalar.new(10)
+
+    assert_equal({ days: -1, seconds: 10 }, (scalar - 1.day).parts)
+    assert_equal({ days: 1, seconds: 10 }, (scalar - -1.day).parts)
+  end
+
   def test_scalar_multiply
     scalar = ActiveSupport::Duration::Scalar.new(5)
 
@@ -375,6 +392,14 @@ class DurationTest < ActiveSupport::TestCase
     assert_equal "no implicit conversion of String into ActiveSupport::Duration::Scalar", exception.message
   end
 
+  def test_scalar_multiply_parts
+    scalar = ActiveSupport::Duration::Scalar.new(1)
+    assert_equal({ days: 2 }, (scalar * 2.days).parts)
+    assert_equal(172800, (scalar * 2.days).value)
+    assert_equal({ days: -2 }, (scalar * -2.days).parts)
+    assert_equal(-172800, (scalar * -2.days).value)
+  end
+
   def test_scalar_divide
     scalar = ActiveSupport::Duration::Scalar.new(10)
 
@@ -394,6 +419,15 @@ class DurationTest < ActiveSupport::TestCase
     assert_equal "no implicit conversion of String into ActiveSupport::Duration::Scalar", exception.message
   end
 
+  def test_scalar_divide_parts
+    scalar = ActiveSupport::Duration::Scalar.new(10)
+
+    assert_equal({ days: 2 }, (scalar / 5.days).parts)
+    assert_equal(172800, (scalar / 5.days).value)
+    assert_equal({ days: -2 }, (scalar / -5.days).parts)
+    assert_equal(-172800, (scalar / -5.days).value)
+  end
+
   def test_twelve_months_equals_one_year
     assert_equal 12.months, 1.year
   end
diff --git a/activesupport/test/core_ext/module/attribute_accessor_test.rb b/activesupport/test/core_ext/module/attribute_accessor_test.rb
index 464a000d59..9b185e9381 100644
--- a/activesupport/test/core_ext/module/attribute_accessor_test.rb
+++ b/activesupport/test/core_ext/module/attribute_accessor_test.rb
@@ -12,7 +12,14 @@ class ModuleAttributeAccessorTest < ActiveSupport::TestCase
       cattr_accessor(:defa) { "default_accessor_value" }
       cattr_reader(:defr) { "default_reader_value" }
       cattr_writer(:defw) { "default_writer_value" }
+      cattr_accessor(:deff) { false }
       cattr_accessor(:quux) { :quux }
+
+      cattr_accessor :def_accessor, default: "default_accessor_value"
+      cattr_reader :def_reader, default: "default_reader_value"
+      cattr_writer :def_writer, default: "default_writer_value"
+      cattr_accessor :def_false, default: false
+      cattr_accessor(:def_priority, default: false) { :no_priority }
     end
     @class = Class.new
     @class.instance_eval { include m }
@@ -24,6 +31,21 @@ class ModuleAttributeAccessorTest < ActiveSupport::TestCase
     assert_nil @object.foo
   end
 
+  def test_mattr_default_keyword_arguments
+    assert_equal "default_accessor_value", @module.def_accessor
+    assert_equal "default_reader_value", @module.def_reader
+    assert_equal "default_writer_value", @module.class_variable_get(:@@def_writer)
+  end
+
+  def test_mattr_can_default_to_false
+    assert_equal false, @module.def_false
+    assert_equal false, @module.deff
+  end
+
+  def test_mattr_default_priority
+    assert_equal false, @module.def_priority
+  end
+
   def test_should_set_mattr_value
     @module.foo = :test
     assert_equal :test, @object.foo
@@ -91,9 +113,23 @@ class ModuleAttributeAccessorTest < ActiveSupport::TestCase
     assert_equal "default_writer_value", @module.class_variable_get("@@defw")
   end
 
-  def test_should_not_invoke_default_value_block_multiple_times
+  def test_method_invocation_should_not_invoke_the_default_block
     count = 0
+
     @module.cattr_accessor(:defcount) { count += 1 }
+
     assert_equal 1, count
+    assert_no_difference "count" do
+      @module.defcount
+    end
+  end
+
+  def test_declaring_multiple_attributes_at_once_invokes_the_block_multiple_times
+    count = 0
+
+    @module.cattr_accessor(:defn1, :defn2) { count += 1 }
+
+    assert_equal 1, @module.defn1
+    assert_equal 2, @module.defn2
   end
 end
diff --git a/activesupport/test/current_attributes_test.rb b/activesupport/test/current_attributes_test.rb
new file mode 100644
index 0000000000..67ef6ef619
--- /dev/null
+++ b/activesupport/test/current_attributes_test.rb
@@ -0,0 +1,96 @@
+require "abstract_unit"
+
+class CurrentAttributesTest < ActiveSupport::TestCase
+  Person = Struct.new(:name, :time_zone)
+
+  class Current < ActiveSupport::CurrentAttributes
+    attribute :world, :account, :person, :request
+    delegate :time_zone, to: :person
+
+    resets { Time.zone = "UTC" }
+
+    def account=(account)
+      super
+      self.person = "#{account}'s person"
+    end
+
+    def person=(person)
+      super
+      Time.zone = person.try(:time_zone)
+    end
+
+    def request
+      "#{super} something"
+    end
+
+    def intro
+      "#{person.name}, in #{time_zone}"
+    end
+  end
+
+  setup { Current.reset }
+
+  test "read and write attribute" do
+    Current.world = "world/1"
+    assert_equal "world/1", Current.world
+  end
+
+  test "read overwritten attribute method" do
+    Current.request = "request/1"
+    assert_equal "request/1 something", Current.request
+  end
+
+  test "set attribute via overwritten method" do
+    Current.account = "account/1"
+    assert_equal "account/1", Current.account
+    assert_equal "account/1's person", Current.person
+  end
+
+  test "set auxiliary class via overwritten method" do
+    Current.person = Person.new("David", "Central Time (US & Canada)")
+    assert_equal "Central Time (US & Canada)", Time.zone.name
+  end
+
+  test "resets auxiliary class via callback" do
+    Current.person = Person.new("David", "Central Time (US & Canada)")
+    assert_equal "Central Time (US & Canada)", Time.zone.name
+
+    Current.reset
+    assert_equal "UTC", Time.zone.name
+  end
+
+  test "set attribute only via scope" do
+    Current.world = "world/1"
+
+    Current.set(world: "world/2") do
+      assert_equal "world/2", Current.world
+    end
+
+    assert_equal "world/1", Current.world
+  end
+
+  test "set multiple attributes" do
+    Current.world = "world/1"
+    Current.account = "account/1"
+
+    Current.set(world: "world/2", account: "account/2") do
+      assert_equal "world/2", Current.world
+      assert_equal "account/2", Current.account
+    end
+
+    assert_equal "world/1", Current.world
+    assert_equal "account/1", Current.account
+  end
+
+  test "delegation" do
+    Current.person = Person.new("David", "Central Time (US & Canada)")
+    assert_equal "Central Time (US & Canada)", Current.time_zone
+    assert_equal "Central Time (US & Canada)", Current.instance.time_zone
+  end
+
+  test "all methods forward to the instance" do
+    Current.person = Person.new("David", "Central Time (US & Canada)")
+    assert_equal "David, in Central Time (US & Canada)", Current.intro
+    assert_equal "David, in Central Time (US & Canada)", Current.instance.intro
+  end
+end
diff --git a/activesupport/test/dependencies_test.rb b/activesupport/test/dependencies_test.rb
index e38d4e83e5..1ea36418ff 100644
--- a/activesupport/test/dependencies_test.rb
+++ b/activesupport/test/dependencies_test.rb
@@ -104,7 +104,7 @@ class DependenciesTest < ActiveSupport::TestCase
     with_loading "dependencies" do
       old_warnings, ActiveSupport::Dependencies.warnings_on_first_load = ActiveSupport::Dependencies.warnings_on_first_load, true
       filename = "check_warnings"
-      expanded = File.expand_path("#{File.dirname(__FILE__)}/dependencies/#{filename}")
+      expanded = File.expand_path("dependencies/#{filename}", __dir__)
       $check_warnings_load_count = 0
 
       assert_not ActiveSupport::Dependencies.loaded.include?(expanded)
@@ -293,7 +293,7 @@ class DependenciesTest < ActiveSupport::TestCase
   end
 
   def test_doesnt_break_normal_require
-    path = File.expand_path("../autoloading_fixtures/load_path", __FILE__)
+    path = File.expand_path("autoloading_fixtures/load_path", __dir__)
     original_path = $:.dup
     $:.push(path)
     with_autoloading_fixtures do
@@ -312,7 +312,7 @@ class DependenciesTest < ActiveSupport::TestCase
   end
 
   def test_doesnt_break_normal_require_nested
-    path = File.expand_path("../autoloading_fixtures/load_path", __FILE__)
+    path = File.expand_path("autoloading_fixtures/load_path", __dir__)
     original_path = $:.dup
     $:.push(path)
 
@@ -332,7 +332,7 @@ class DependenciesTest < ActiveSupport::TestCase
   end
 
   def test_require_returns_true_when_file_not_yet_required
-    path = File.expand_path("../autoloading_fixtures/load_path", __FILE__)
+    path = File.expand_path("autoloading_fixtures/load_path", __dir__)
     original_path = $:.dup
     $:.push(path)
 
@@ -345,7 +345,7 @@ class DependenciesTest < ActiveSupport::TestCase
   end
 
   def test_require_returns_true_when_file_not_yet_required_even_when_no_new_constants_added
-    path = File.expand_path("../autoloading_fixtures/load_path", __FILE__)
+    path = File.expand_path("autoloading_fixtures/load_path", __dir__)
     original_path = $:.dup
     $:.push(path)
 
@@ -359,7 +359,7 @@ class DependenciesTest < ActiveSupport::TestCase
   end
 
   def test_require_returns_false_when_file_already_required
-    path = File.expand_path("../autoloading_fixtures/load_path", __FILE__)
+    path = File.expand_path("autoloading_fixtures/load_path", __dir__)
     original_path = $:.dup
     $:.push(path)
 
@@ -379,7 +379,7 @@ class DependenciesTest < ActiveSupport::TestCase
   end
 
   def test_load_returns_true_when_file_found
-    path = File.expand_path("../autoloading_fixtures/load_path", __FILE__)
+    path = File.expand_path("autoloading_fixtures/load_path", __dir__)
     original_path = $:.dup
     $:.push(path)
 
@@ -438,7 +438,7 @@ class DependenciesTest < ActiveSupport::TestCase
 
   def test_loadable_constants_for_path_should_handle_relative_paths
     fake_root = "dependencies"
-    relative_root = File.dirname(__FILE__) + "/dependencies"
+    relative_root = File.expand_path("dependencies", __dir__)
     ["", "/"].each do |suffix|
       with_loading fake_root + suffix do
         assert_equal ["A::B"], ActiveSupport::Dependencies.loadable_constants_for_path(relative_root + "/a/b")
@@ -463,7 +463,7 @@ class DependenciesTest < ActiveSupport::TestCase
   end
 
   def test_loadable_constants_with_load_path_without_trailing_slash
-    path = File.dirname(__FILE__) + "/autoloading_fixtures/class_folder/inline_class.rb"
+    path = File.expand_path("autoloading_fixtures/class_folder/inline_class.rb", __dir__)
     with_loading "autoloading_fixtures/class/" do
       assert_equal [], ActiveSupport::Dependencies.loadable_constants_for_path(path)
     end
@@ -991,7 +991,7 @@ class DependenciesTest < ActiveSupport::TestCase
   def test_remove_constant_does_not_trigger_loading_autoloads
     constant = "ShouldNotBeAutoloaded"
     Object.class_eval do
-      autoload constant, File.expand_path("../autoloading_fixtures/should_not_be_required", __FILE__)
+      autoload constant, File.expand_path("autoloading_fixtures/should_not_be_required", __dir__)
     end
 
     assert_nil ActiveSupport::Dependencies.remove_constant(constant), "Kernel#autoload has been triggered by remove_constant"
diff --git a/activesupport/test/dependencies_test_helpers.rb b/activesupport/test/dependencies_test_helpers.rb
index 9bc63ed89e..451195a143 100644
--- a/activesupport/test/dependencies_test_helpers.rb
+++ b/activesupport/test/dependencies_test_helpers.rb
@@ -1,7 +1,7 @@
 module DependenciesTestHelpers
   def with_loading(*from)
     old_mechanism, ActiveSupport::Dependencies.mechanism = ActiveSupport::Dependencies.mechanism, :load
-    this_dir = File.dirname(__FILE__)
+    this_dir = __dir__
     parent_dir = File.dirname(this_dir)
     path_copy = $LOAD_PATH.dup
     $LOAD_PATH.unshift(parent_dir) unless $LOAD_PATH.include?(parent_dir)
diff --git a/activesupport/test/inflector_test.rb b/activesupport/test/inflector_test.rb
index 14bc10513b..ef956eda90 100644
--- a/activesupport/test/inflector_test.rb
+++ b/activesupport/test/inflector_test.rb
@@ -420,6 +420,8 @@ class InflectorTest < ActiveSupport::TestCase
       inflect.singular(/es$/, "")
 
       inflect.irregular("el", "los")
+
+      inflect.uncountable("agua")
     end
 
     assert_equal("hijos", "hijo".pluralize(:es))
@@ -432,12 +434,17 @@ class InflectorTest < ActiveSupport::TestCase
     assert_equal("los", "el".pluralize(:es))
     assert_equal("els", "el".pluralize)
 
+    assert_equal("agua", "agua".pluralize(:es))
+    assert_equal("aguas", "agua".pluralize)
+
     ActiveSupport::Inflector.inflections(:es) { |inflect| inflect.clear }
 
     assert ActiveSupport::Inflector.inflections(:es).plurals.empty?
     assert ActiveSupport::Inflector.inflections(:es).singulars.empty?
+    assert ActiveSupport::Inflector.inflections(:es).uncountables.empty?
     assert !ActiveSupport::Inflector.inflections.plurals.empty?
     assert !ActiveSupport::Inflector.inflections.singulars.empty?
+    assert !ActiveSupport::Inflector.inflections.uncountables.empty?
   end
 
   def test_clear_all
diff --git a/activesupport/test/number_helper_test.rb b/activesupport/test/number_helper_test.rb
index dc0c34d4e2..4caf1428ea 100644
--- a/activesupport/test/number_helper_test.rb
+++ b/activesupport/test/number_helper_test.rb
@@ -321,12 +321,18 @@ module ActiveSupport
           gangster = { hundred: "hundred bucks", million: "thousand quids" }
           assert_equal "1 hundred bucks", number_helper.number_to_human(100, units: gangster)
           assert_equal "25 hundred bucks", number_helper.number_to_human(2500, units: gangster)
+          assert_equal "1000 hundred bucks", number_helper.number_to_human(100_000, units: gangster)
+          assert_equal "1 thousand quids", number_helper.number_to_human(999_999, units: gangster)
+          assert_equal "1 thousand quids", number_helper.number_to_human(1_000_000, units: gangster)
           assert_equal "25 thousand quids", number_helper.number_to_human(25000000, units: gangster)
           assert_equal "12300 thousand quids", number_helper.number_to_human(12345000000, units: gangster)
 
           #Spaces are stripped from the resulting string
           assert_equal "4", number_helper.number_to_human(4, units: { unit: "", ten: "tens " })
           assert_equal "4.5  tens", number_helper.number_to_human(45, units: { unit: "", ten: " tens   " })
+
+          #Uses only the provided units and does not try to use larger ones
+          assert_equal "1000 kilometers", number_helper.number_to_human(1_000_000, units: { unit: "meter", thousand: "kilometers" })
         end
       end
 
diff --git a/activesupport/test/test_case_test.rb b/activesupport/test/test_case_test.rb
index af7fc44d66..40dfbe2542 100644
--- a/activesupport/test/test_case_test.rb
+++ b/activesupport/test/test_case_test.rb
@@ -237,9 +237,6 @@ class AssertDifferenceTest < ActiveSupport::TestCase
   end
 end
 
-class AlsoDoingNothingTest < ActiveSupport::TestCase
-end
-
 # Setup and teardown callbacks.
 class SetupAndTeardownTest < ActiveSupport::TestCase
   setup :reset_callback_record, :foo
diff --git a/activesupport/test/testing/file_fixtures_test.rb b/activesupport/test/testing/file_fixtures_test.rb
index faa81b5e75..9f28252c31 100644
--- a/activesupport/test/testing/file_fixtures_test.rb
+++ b/activesupport/test/testing/file_fixtures_test.rb
@@ -3,7 +3,7 @@ require "abstract_unit"
 require "pathname"
 
 class FileFixturesTest < ActiveSupport::TestCase
-  self.file_fixture_path = File.expand_path("../../file_fixtures", __FILE__)
+  self.file_fixture_path = File.expand_path("../file_fixtures", __dir__)
 
   test "#file_fixture returns Pathname to file fixture" do
     path = file_fixture("sample.txt")
@@ -20,7 +20,7 @@ class FileFixturesTest < ActiveSupport::TestCase
 end
 
 class FileFixturesPathnameDirectoryTest < ActiveSupport::TestCase
-  self.file_fixture_path = Pathname.new(File.expand_path("../../file_fixtures", __FILE__))
+  self.file_fixture_path = Pathname.new(File.expand_path("../file_fixtures", __dir__))
 
   test "#file_fixture_path returns Pathname to file fixture" do
     path = file_fixture("sample.txt")
diff --git a/activesupport/test/xml_mini/jdom_engine_test.rb b/activesupport/test/xml_mini/jdom_engine_test.rb
index e783cea67c..fc35ac113b 100644
--- a/activesupport/test/xml_mini/jdom_engine_test.rb
+++ b/activesupport/test/xml_mini/jdom_engine_test.rb
@@ -2,7 +2,7 @@ require_relative "xml_mini_engine_test"
 
 XMLMiniEngineTest.run_with_platform("java") do
   class JDOMEngineTest < XMLMiniEngineTest
-    FILES_DIR = File.dirname(__FILE__) + "/../fixtures/xml"
+    FILES_DIR = File.expand_path("../fixtures/xml", __dir__)
 
     def test_not_allowed_to_expand_entities_to_files
       attack_xml = <<-EOT