Fix coercion for array type: do not coerce array value if type is the…

… same as specified

lib/shallow_attributes/type/array.rb

@@ -28,7 +28,8 @@ def coerce(values, options = {})
           raise ShallowAttributes::Type::InvalidValueError, %(Invalid value "#{values}" for type "Array")
         end
         values.map! do |value|
-          ShallowAttributes::Type.coerce(item_klass(options[:of]), value)
+          klass_const = item_klass(options[:of])
+          value.is_a?(klass_const) ? value : ShallowAttributes::Type.coerce(klass_const, value)
         end
       end
 

test/array_type_test.rb

@@ -27,7 +27,16 @@
       end
     end
 
-    describe 'when value is Array' do
+    describe 'when value is Array of specified types' do
+      let(:arbitrary_class) { Class.new }
+      let(:arbitrary_value) { arbitrary_class.new }
+
+      it 'returns array of non-coerced values' do
+        type.coerce([arbitrary_value], of: arbitrary_class).must_equal [arbitrary_value]
+      end
+    end
+
+    describe 'when value is Array of non-specified types' do
       it 'returns array of specific type' do
         type.coerce([], of: Integer).must_equal []
         type.coerce(['1', '2'], of: Integer).must_equal [1, 2]