Don't modify the columns hash to set defaults from the attributes API

Nothing is directly using the columns for the default values anymore.
This step helps us get closer not not mutating the columns hash.

3 files changed, 39 insertions, 14 deletions

diff --git a/activerecord/lib/active_record/attributes.rb b/activerecord/lib/active_record/attributes.rb
index 890a1314d9..3288108a6a 100644
--- a/activerecord/lib/active_record/attributes.rb
+++ b/activerecord/lib/active_record/attributes.rb
@@ -6,7 +6,9 @@ module ActiveRecord
 
     included do
       class_attribute :user_provided_columns, instance_accessor: false # :internal:
+      class_attribute :user_provided_defaults, instance_accessor: false # :internal:
       self.user_provided_columns = {}
+      self.user_provided_defaults = {}
     end
 
     module ClassMethods # :nodoc:
@@ -77,7 +79,11 @@ module ActiveRecord
         name = name.to_s
         clear_caches_calculated_from_columns
         # Assign a new hash to ensure that subclasses do not share a hash
-        self.user_provided_columns = user_provided_columns.merge(name => connection.new_column(name, options[:default], cast_type))
+        self.user_provided_columns = user_provided_columns.merge(name => cast_type)
+
+        if options.key?(:default)
+          self.user_provided_defaults = user_provided_defaults.merge(name => options[:default])
+        end
       end
 
       # Returns an array of column objects for the table associated with this class.
@@ -99,11 +105,18 @@ module ActiveRecord
 
       def add_user_provided_columns(schema_columns)
         existing_columns = schema_columns.map do |column|
-          user_provided_columns[column.name] || column
+          new_type = user_provided_columns[column.name]
+          if new_type
+            column.with_type(new_type)
+          else
+            column
+          end
         end
 
         existing_column_names = existing_columns.map(&:name)
-        new_columns = user_provided_columns.except(*existing_column_names).values
+        new_columns = user_provided_columns.except(*existing_column_names).map do |(name, type)|
+          connection.new_column(name, nil, type)
+        end
 
         existing_columns + new_columns
       end
@@ -117,6 +130,10 @@ module ActiveRecord
         @content_columns = nil
         @default_attributes = nil
       end
+
+      def raw_default_values
+        super.merge(user_provided_defaults)
+      end
     end
   end
 end
diff --git a/activerecord/lib/active_record/model_schema.rb b/activerecord/lib/active_record/model_schema.rb
index 31ff08a89d..a444aac23c 100644
--- a/activerecord/lib/active_record/model_schema.rb
+++ b/activerecord/lib/active_record/model_schema.rb
@@ -252,7 +252,7 @@ module ActiveRecord
 
       def _default_attributes # :nodoc:
         @default_attributes ||= attributes_builder.build_from_database(
-          columns_hash.transform_values(&:default))
+          raw_default_values)
       end
 
       # Returns an array of column names as strings.
@@ -331,6 +331,10 @@ module ActiveRecord
           base.table_name
         end
       end
+
+      def raw_default_values
+        columns_hash.transform_values(&:default)
+      end
     end
   end
 end
diff --git a/activerecord/test/cases/attributes_test.rb b/activerecord/test/cases/attributes_test.rb
index 79ef0502cb..dbe1eb48db 100644
--- a/activerecord/test/cases/attributes_test.rb
+++ b/activerecord/test/cases/attributes_test.rb
@@ -20,7 +20,7 @@ end
 
 module ActiveRecord
   class CustomPropertiesTest < ActiveRecord::TestCase
-    def test_overloading_types
+    test "overloading types" do
       data = OverloadedType.new
 
       data.overloaded_float = "1.1"
@@ -30,7 +30,7 @@ module ActiveRecord
       assert_equal 1.1, data.unoverloaded_float
     end
 
-    def test_overloaded_properties_save
+    test "overloaded properties save" do
       data = OverloadedType.new
 
       data.overloaded_float = "2.2"
@@ -43,18 +43,18 @@ module ActiveRecord
       assert_kind_of Float, UnoverloadedType.last.overloaded_float
     end
 
-    def test_properties_assigned_in_constructor
+    test "properties assigned in constructor" do
       data = OverloadedType.new(overloaded_float: '3.3')
 
       assert_equal 3, data.overloaded_float
     end
 
-    def test_overloaded_properties_with_limit
+    test "overloaded properties with limit" do
       assert_equal 50, OverloadedType.columns_hash['overloaded_string_with_limit'].limit
       assert_equal 255, UnoverloadedType.columns_hash['overloaded_string_with_limit'].limit
     end
 
-    def test_nonexistent_attribute
+    test "nonexistent attribute" do
       data = OverloadedType.new(non_existent_decimal: 1)
 
       assert_equal BigDecimal.new(1), data.non_existent_decimal
@@ -63,7 +63,7 @@ module ActiveRecord
       end
     end
 
-    def test_changing_defaults
+    test "changing defaults" do
       data = OverloadedType.new
       unoverloaded_data = UnoverloadedType.new
 
@@ -71,24 +71,28 @@ module ActiveRecord
       assert_equal 'the original default', unoverloaded_data.string_with_default
     end
 
-    def test_children_inherit_custom_properties
+    test "defaults are not touched on the columns" do
+      assert_equal 'the original default', OverloadedType.columns_hash['string_with_default'].default
+    end
+
+    test "children inherit custom properties" do
       data = ChildOfOverloadedType.new(overloaded_float: '4.4')
 
       assert_equal 4, data.overloaded_float
     end
 
-    def test_children_can_override_parents
+    test "children can override parents" do
       data = GrandchildOfOverloadedType.new(overloaded_float: '4.4')
 
       assert_equal 4.4, data.overloaded_float
     end
 
-    def test_overloading_properties_does_not_change_column_order
+    test "overloading properties does not change column order" do
       column_names = OverloadedType.column_names
       assert_equal %w(id overloaded_float unoverloaded_float overloaded_string_with_limit string_with_default non_existent_decimal), column_names
     end
 
-    def test_caches_are_cleared
+    test "caches are cleared" do
       klass = Class.new(OverloadedType)
 
       assert_equal 6, klass.columns.length