Patch #1759: Backport of PEP 3129 class decorators

with some help from Georg

3 files changed, 47 insertions, 1 deletions

diff --git a/Lib/test/test_ast.py b/Lib/test/test_ast.py
index 14fc01026f..03dd5b5193 100644
--- a/Lib/test/test_ast.py
+++ b/Lib/test/test_ast.py
@@ -156,7 +156,7 @@ def run_tests():
 #### EVERYTHING BELOW IS GENERATED #####
 exec_results = [
 ('Module', [('FunctionDef', (1, 0), 'f', ('arguments', [], None, None, []), [('Pass', (1, 9))], [])]),
-('Module', [('ClassDef', (1, 0), 'C', [], [('Pass', (1, 8))])]),
+('Module', [('ClassDef', (1, 0), 'C', [], [('Pass', (1, 8))], [])]),
 ('Module', [('FunctionDef', (1, 0), 'f', ('arguments', [], None, None, []), [('Return', (1, 8), ('Num', (1, 15), 1))], [])]),
 ('Module', [('Delete', (1, 0), [('Name', (1, 4), 'v', ('Del',))])]),
 ('Module', [('Assign', (1, 0), [('Name', (1, 0), 'v', ('Store',))], ('Num', (1, 4), 1))]),
diff --git a/Lib/test/test_decorators.py b/Lib/test/test_decorators.py
index 56aa5e1323..cf2bc3000c 100644
--- a/Lib/test/test_decorators.py
+++ b/Lib/test/test_decorators.py
@@ -266,8 +266,44 @@ class TestDecorators(unittest.TestCase):
         self.assertEqual(bar(), 42)
         self.assertEqual(actions, expected_actions)
 
+class TestClassDecorators(unittest.TestCase):
+
+    def test_simple(self):
+        def plain(x):
+            x.extra = 'Hello'
+            return x
+        @plain
+        class C(object): pass
+        self.assertEqual(C.extra, 'Hello')
+
+    def test_double(self):
+        def ten(x):
+            x.extra = 10
+            return x
+        def add_five(x):
+            x.extra += 5
+            return x
+
+        @add_five
+        @ten
+        class C(object): pass
+        self.assertEqual(C.extra, 15)
+
+    def test_order(self):
+        def applied_first(x):
+            x.extra = 'first'
+            return x
+        def applied_second(x):
+            x.extra = 'second'
+            return x
+        @applied_second
+        @applied_first
+        class C(object): pass
+        self.assertEqual(C.extra, 'second')
+
 def test_main():
     test_support.run_unittest(TestDecorators)
+    test_support.run_unittest(TestClassDecorators)
 
 if __name__=="__main__":
     test_main()
diff --git a/Lib/test/test_grammar.py b/Lib/test/test_grammar.py
index d4bcfda017..e2bb3eb9e6 100644
--- a/Lib/test/test_grammar.py
+++ b/Lib/test/test_grammar.py
@@ -779,6 +779,16 @@ hello world
             def meth1(self): pass
             def meth2(self, arg): pass
             def meth3(self, a1, a2): pass
+        # decorator: '@' dotted_name [ '(' [arglist] ')' ] NEWLINE
+        # decorators: decorator+
+        # decorated: decorators (classdef | funcdef)
+        def class_decorator(x):
+            x.decorated = True
+            return x
+        @class_decorator
+        class G:
+            pass
+        self.assertEqual(G.decorated, True)
 
     def testListcomps(self):
         # list comprehension tests