Merge pull request rails#53658 from fatkodima/reset-cpk-when-configuring-pk

Properly reset composite primary key configuration when setting a primary key

Author: kamipo

activerecord/lib/active_record/attribute_methods/primary_key.rb

@@ -129,12 +129,13 @@ def get_primary_key(base_name) # :nodoc:
           #   Project.primary_key # => "foo_id"
           def primary_key=(value)
             @primary_key = if value.is_a?(Array)
-              @composite_primary_key = true
               include CompositePrimaryKey
               @primary_key = value.map { |v| -v.to_s }.freeze
             elsif value
               -value.to_s
             end
+
+            @composite_primary_key = value.is_a?(Array)
             @attributes_builder = nil
           end
 

activerecord/test/cases/primary_keys_test.rb

@@ -256,6 +256,17 @@ def test_assign_id_raises_error_if_primary_key_doesnt_exist
     assert_raises(ActiveModel::MissingAttributeError) { dashboard.id = "1" }
   end
 
+  def test_reconfiguring_primary_key_resets_composite_primary_key
+    klass = Class.new(ActiveRecord::Base) do
+      self.table_name = "cpk_books"
+    end
+
+    assert_predicate klass, :composite_primary_key?
+
+    klass.primary_key = :id
+    assert_not_predicate klass, :composite_primary_key?
+  end
+
   def composite_primary_key_is_false_for_a_non_cpk_model
     assert_not_predicate Dashboard, :composite_primary_key?
   end