+# This file is part of NIT ( http://www.nitlanguage.org ).
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Verification if it's possible to define a contract in different context (abstract class, interface and class) and it's possible to inherit it.
+
+class MyClass
+ fun foo(x: Int, y: Float)is abstract, expects(x != 10)
+end
+
+abstract class AbstractClass
+ fun bar(x: Int, y: Float)is abstract, expects(x >= 1), ensures(y == 10.0)
+end
+
+interface Interface
+ fun baz(x: Int, y: Float)is abstract, ensures(y <= 10.0, y == 42.0)
+end
+
+
+class MySubClass
+ super MyClass
+ super Interface
+ super AbstractClass
+
+ redef fun foo(x: Int, y: Float)
+ do
+ if x == 10 then print "Error"
+ end
+
+ redef fun baz(x: Int, y: Float)
+ do
+
+ end
+
+ redef fun bar(x: Int, y: Float)
+ do
+ if x < 1 then print "Error"
+ end
+end
+
+
+var first = new MySubClass
+first.foo(11,2.0) # Ok
+first.bar(1,10.0) # Ok
+first.baz(9,42.0) # Fail y > 10 (y = 42.0)