Merge pull request rails#43296 from the-spectator/filter_default_value

Fixes rails#43279 by filtering unchanged attributes when default function is available for insert

Author: byroot

activerecord/CHANGELOG.md

@@ -1,3 +1,7 @@
+*   Filter unchanged attributes with default function from insert query when `partial_inserts` is disabled.
+
+    *Akshay Birajdar*, *Jacopo Beschi*
+
 *   Add support for FILTER clause (SQL:2003) to Arel.
 
     Currently supported by PostgreSQL 9.4+ and SQLite 3.30+.

activerecord/lib/active_record/attribute_methods/dirty.rb

@@ -229,7 +229,13 @@ def attribute_names_for_partial_updates
         end
 
         def attribute_names_for_partial_inserts
-          partial_inserts? ? changed_attribute_names_to_save : attribute_names
+          if partial_inserts?
+            changed_attribute_names_to_save
+          else
+            attribute_names.reject do |attr_name|
+              !attribute_changed?(attr_name) && column_for_attribute(attr_name).default_function
+            end
+          end
         end
     end
   end

activerecord/test/cases/dirty_test.rb

@@ -941,6 +941,37 @@ def check_around
     assert_not_predicate person, :changed?
   end
 
+  unless current_adapter?(:SQLite3Adapter)
+    test "partial insert off with unchanged default function attribute" do
+      with_partial_writes Aircraft, false do
+        aircraft = Aircraft.new(name: "Boeing")
+        assert_equal "Boeing", aircraft.name
+
+        aircraft.save!
+        aircraft.reload
+
+        assert_equal "Boeing", aircraft.name
+        assert_equal Time.now.utc.strftime("%Y-%m-%d %H:%M:%S"), aircraft.manufactured_at.strftime("%Y-%m-%d %H:%M:%S")
+      end
+    end
+
+    test "partial insert off with changed default function attribute" do
+      with_partial_writes Aircraft, false do
+        manufactured_at = 1.years.ago
+        aircraft = Aircraft.new(name: "Boeing2", manufactured_at: manufactured_at)
+
+        assert_equal "Boeing2", aircraft.name
+        assert_equal manufactured_at.to_i, aircraft.manufactured_at.to_i
+
+        aircraft.save!
+        aircraft.reload
+
+        assert_equal "Boeing2", aircraft.name
+        assert_equal manufactured_at.utc.strftime("%Y-%m-%d %H:%M:%S"), aircraft.manufactured_at.strftime("%Y-%m-%d %H:%M:%S")
+      end
+    end
+  end
+
   private
     def with_partial_writes(klass, on = true)
       old_inserts = klass.partial_inserts?

activerecord/test/schema/schema.rb

@@ -38,6 +38,7 @@
     t.string :name
     t.integer :wheels_count, default: 0, null: false
     t.datetime :wheels_owned_at
+    t.timestamp :manufactured_at, default: -> { "CURRENT_TIMESTAMP" }
   end
 
   create_table :articles, force: true do |t|