Make `_before_type_cast` actually be before type cast

- The following is now true for all types, all the time
  - `model.attribute_before_type_cast == given_value`
  - `model.attribute == model.save_and_reload.attribute`
  - `model.attribute == model.dup.attribute`
  - `model.attribute == YAML.load(YAML.dump(model)).attribute`
- Removes the remaining types implementing `type_cast_for_write`
- Simplifies the implementation of time zone aware attributes
- Brings tz aware attributes closer to being implemented as an attribute
  decorator
- Adds additional point of control for custom types

6 files changed, 12 insertions, 6 deletions

diff --git a/activerecord/test/cases/adapters/postgresql/composite_test.rb b/activerecord/test/cases/adapters/postgresql/composite_test.rb
index a925263098..0b48fe9af8 100644
--- a/activerecord/test/cases/adapters/postgresql/composite_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/composite_test.rb
@@ -90,7 +90,11 @@ class PostgresqlCompositeWithCustomOIDTest < ActiveRecord::TestCase
       end
     end
 
-    def type_cast_for_write(value)
+    def type_cast_from_user(value)
+      value
+    end
+
+    def type_cast_for_database(value)
       return if value.nil?
       "(#{value.city},#{value.street})"
     end
diff --git a/activerecord/test/cases/adapters/postgresql/hstore_test.rb b/activerecord/test/cases/adapters/postgresql/hstore_test.rb
index a6482786c7..0b8c9fc052 100644
--- a/activerecord/test/cases/adapters/postgresql/hstore_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/hstore_test.rb
@@ -106,6 +106,7 @@ class PostgresqlHstoreTest < ActiveRecord::TestCase
 
     def test_cast_value_on_write
       x = Hstore.new tags: {"bool" => true, "number" => 5}
+      assert_equal({"bool" => true, "number" => 5}, x.tags_before_type_cast)
       assert_equal({"bool" => "true", "number" => "5"}, x.tags)
       x.save
       assert_equal({"bool" => "true", "number" => "5"}, x.reload.tags)
diff --git a/activerecord/test/cases/adapters/postgresql/json_test.rb b/activerecord/test/cases/adapters/postgresql/json_test.rb
index 61d4e2b8ae..eab6049956 100644
--- a/activerecord/test/cases/adapters/postgresql/json_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/json_test.rb
@@ -68,6 +68,7 @@ class PostgresqlJSONTest < ActiveRecord::TestCase
 
   def test_cast_value_on_write
     x = JsonDataType.new payload: {"string" => "foo", :symbol => :bar}
+    assert_equal({"string" => "foo", :symbol => :bar}, x.payload_before_type_cast)
     assert_equal({"string" => "foo", "symbol" => "bar"}, x.payload)
     x.save
     assert_equal({"string" => "foo", "symbol" => "bar"}, x.reload.payload)
diff --git a/activerecord/test/cases/attribute_decorators_test.rb b/activerecord/test/cases/attribute_decorators_test.rb
index f17cc02f53..416eb650f6 100644
--- a/activerecord/test/cases/attribute_decorators_test.rb
+++ b/activerecord/test/cases/attribute_decorators_test.rb
@@ -15,6 +15,8 @@ module ActiveRecord
       def type_cast(value)
         "#{super} #{@decoration}"
       end
+
+      alias type_cast_from_user type_cast
     end
 
     setup do
diff --git a/activerecord/test/cases/dirty_test.rb b/activerecord/test/cases/dirty_test.rb
index 2beac84fb1..87f24e32b2 100644
--- a/activerecord/test/cases/dirty_test.rb
+++ b/activerecord/test/cases/dirty_test.rb
@@ -616,17 +616,15 @@ class DirtyTest < ActiveRecord::TestCase
     end
   end
 
-  test "defaults with type that implements `type_cast_for_write`" do
+  test "defaults with type that implements `type_cast_for_database`" do
     type = Class.new(ActiveRecord::Type::Value) do
       def type_cast(value)
         value.to_i
       end
 
-      def type_cast_for_write(value)
+      def type_cast_for_database(value)
         value.to_s
       end
-
-      alias type_cast_for_database type_cast_for_write
     end
 
     model_class = Class.new(ActiveRecord::Base) do
diff --git a/activerecord/test/cases/reflection_test.rb b/activerecord/test/cases/reflection_test.rb
index 793e193329..70d52634f7 100644
--- a/activerecord/test/cases/reflection_test.rb
+++ b/activerecord/test/cases/reflection_test.rb
@@ -96,7 +96,7 @@ class ReflectionTest < ActiveRecord::TestCase
     object = Object.new
 
     assert_equal object, column.type_cast(object)
-    assert_equal object, column.type_cast_for_write(object)
+    assert_equal object, column.type_cast_from_user(object)
     assert_equal object, column.type_cast_for_database(object)
   end