lookup MRO node: add unittest to test against attr addition in the MRO chain

Author: cosminbasca

graalpython/com.oracle.graal.python.test/src/tests/test_mro.py

@@ -0,0 +1,118 @@
+# Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+# DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+#
+# The Universal Permissive License (UPL), Version 1.0
+#
+# Subject to the condition set forth below, permission is hereby granted to any
+# person obtaining a copy of this software, associated documentation and/or
+# data (collectively the "Software"), free of charge and under any and all
+# copyright rights in the Software, and any and all patent rights owned or
+# freely licensable by each licensor hereunder covering either (i) the
+# unmodified Software as contributed to or provided by such licensor, or (ii)
+# the Larger Works (as defined below), to deal in both
+#
+# (a) the Software, and
+#
+# (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
+# one is included with the Software each a "Larger Work" to which the Software
+# is contributed by such licensors),
+#
+# without restriction, including without limitation the rights to copy, create
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+# use, sell, offer for sale, import, export, have made, and have sold the
+# Software and the Larger Work(s), and to sublicense the foregoing rights on
+# either these or other terms.
+#
+# This license is subject to the following condition:
+#
+# The above copyright notice and either this complete permission notice or at a
+# minimum a reference to the UPL must be included in all copies or substantial
+# portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+
+def test_class_attr_change():
+    class A(object):
+        counter = 0
+
+    for i in range(10):
+        A.counter += 1
+
+    assert A.counter == 10
+
+
+def test_class_attr_deleted():
+    class A(object):
+        counter = 0
+
+    class B(A):
+        counter = 1
+
+    for i in range(10):
+        B.counter += 1
+
+    assert B.counter == 11
+    assert A.counter == 0
+    del B.counter
+    assert B.counter == 0
+
+    for i in range(10):
+        A.counter += 1
+    assert A.counter == 10
+
+
+def test_class_attr_added():
+    class A(object):
+        counter = 0
+
+    class B(A):
+        pass
+
+    for i in range(10):
+        B.counter += 1
+
+    assert B.counter == 10
+    assert A.counter == 0
+    B.counter = 1
+    assert B.counter == 1
+
+    for i in range(10):
+        A.counter += 1
+    assert A.counter == 10
+
+
+def test_class_attr_add_del():
+    class A:
+        foo = 1
+
+    class B(A):
+        foo = 2
+
+    class C(B):
+        foo = 3
+
+    C.foo += 1
+    C.foo += 1
+    C.foo += 1
+    C.foo += 1
+    C.foo += 1
+    C.foo += 1
+    C.foo += 1
+
+    assert C.foo == 10
+    del C.foo
+    assert C.foo == 2
+    del B.foo
+    assert C.foo == 1
+    B.foo = 5
+    assert C.foo == 5
+    C.foo = 10
+    assert C.foo == 10
+