2 files changed, 33 insertions, 7 deletions
diff --git a/activerecord/test/cases/type/decimal_test.rb b/activerecord/test/cases/type/decimal_test.rb
new file mode 100644
index 0000000000..951cd879dd
--- /dev/null
+++ b/activerecord/test/cases/type/decimal_test.rb
@@ -0,0 +1,33 @@
+require "cases/helper"
+
+module ActiveRecord
+  module Type
+    class DecimalTest < ActiveRecord::TestCase
+      def test_type_cast_decimal
+        type = Decimal.new
+        assert_equal BigDecimal.new("0"), type.type_cast_from_user(BigDecimal.new("0"))
+        assert_equal BigDecimal.new("123"), type.type_cast_from_user(123.0)
+        assert_equal BigDecimal.new("1"), type.type_cast_from_user(:"1")
+      end
+
+      def test_type_cast_decimal_from_rational_with_precision
+        type = Decimal.new(precision: 2)
+        assert_equal BigDecimal("0.33"), type.type_cast_from_user(Rational(1, 3))
+      end
+
+      def test_type_cast_decimal_from_rational_without_precision_defaults_to_18_36
+        type = Decimal.new
+        assert_equal BigDecimal("0.333333333333333333E0"), type.type_cast_from_user(Rational(1, 3))
+      end
+
+      def test_type_cast_decimal_from_object_responding_to_d
+        value = Object.new
+        def value.to_d
+          BigDecimal.new("1")
+        end
+        type = Decimal.new
+        assert_equal BigDecimal("1"), type.type_cast_from_user(value)
+      end
+    end
+  end
+end
diff --git a/activerecord/test/cases/types_test.rb b/activerecord/test/cases/types_test.rb
index 47cf775cb6..5c54812f30 100644
--- a/activerecord/test/cases/types_test.rb
+++ b/activerecord/test/cases/types_test.rb
@@ -95,13 +95,6 @@ module ActiveRecord
         assert_not type.changed?(nil, nil, nil)
       end
 
-      def test_type_cast_decimal
-        type = Type::Decimal.new
-        assert_equal BigDecimal.new("0"), type.type_cast_from_user(BigDecimal.new("0"))
-        assert_equal BigDecimal.new("123"), type.type_cast_from_user(123.0)
-        assert_equal BigDecimal.new("1"), type.type_cast_from_user(:"1")
-      end
-
       def test_type_cast_binary
         type = Type::Binary.new
         assert_equal nil, type.type_cast_from_user(nil)