bpo-12022: Change error type for bad objects in "with" and "async with" (GH-26809)

A TypeError is now raised instead of an AttributeError in
"with" and "async with" statements for objects which do not
support the context manager or asynchronous context manager
protocols correspondingly.

3 files changed, 8 insertions, 8 deletions

diff --git a/Lib/test/test_contextlib.py b/Lib/test/test_contextlib.py
index 453ef6c..dbc3f5f 100644
--- a/Lib/test/test_contextlib.py
+++ b/Lib/test/test_contextlib.py
@@ -491,7 +491,7 @@ class TestContextDecorator(unittest.TestCase):
             def __exit__(self, *exc):
                 pass
 
-        with self.assertRaises(AttributeError):
+        with self.assertRaisesRegex(TypeError, 'the context manager'):
             with mycontext():
                 pass
 
@@ -503,7 +503,7 @@ class TestContextDecorator(unittest.TestCase):
             def __uxit__(self, *exc):
                 pass
 
-        with self.assertRaises(AttributeError):
+        with self.assertRaisesRegex(TypeError, 'the context manager.*__exit__'):
             with mycontext():
                 pass
 
diff --git a/Lib/test/test_coroutines.py b/Lib/test/test_coroutines.py
index a6a199e..9b83244 100644
--- a/Lib/test/test_coroutines.py
+++ b/Lib/test/test_coroutines.py
@@ -1212,7 +1212,7 @@ class CoroutineTest(unittest.TestCase):
             async with CM():
                 body_executed = True
 
-        with self.assertRaisesRegex(AttributeError, '__aexit__'):
+        with self.assertRaisesRegex(TypeError, 'asynchronous context manager.*__aexit__'):
             run_async(foo())
         self.assertIs(body_executed, False)
 
@@ -1228,7 +1228,7 @@ class CoroutineTest(unittest.TestCase):
             async with CM():
                 body_executed = True
 
-        with self.assertRaisesRegex(AttributeError, '__aenter__'):
+        with self.assertRaisesRegex(TypeError, 'asynchronous context manager'):
             run_async(foo())
         self.assertIs(body_executed, False)
 
@@ -1243,7 +1243,7 @@ class CoroutineTest(unittest.TestCase):
             async with CM():
                 body_executed = True
 
-        with self.assertRaisesRegex(AttributeError, '__aenter__'):
+        with self.assertRaisesRegex(TypeError, 'asynchronous context manager'):
             run_async(foo())
         self.assertIs(body_executed, False)
 
diff --git a/Lib/test/test_with.py b/Lib/test/test_with.py
index f21bf65..07522bd 100644
--- a/Lib/test/test_with.py
+++ b/Lib/test/test_with.py
@@ -117,7 +117,7 @@ class FailureTestCase(unittest.TestCase):
         def fooLacksEnter():
             foo = LacksEnter()
             with foo: pass
-        self.assertRaisesRegex(AttributeError, '__enter__', fooLacksEnter)
+        self.assertRaisesRegex(TypeError, 'the context manager', fooLacksEnter)
 
     def testEnterAttributeError2(self):
         class LacksEnterAndExit(object):
@@ -126,7 +126,7 @@ class FailureTestCase(unittest.TestCase):
         def fooLacksEnterAndExit():
             foo = LacksEnterAndExit()
             with foo: pass
-        self.assertRaisesRegex(AttributeError, '__enter__', fooLacksEnterAndExit)
+        self.assertRaisesRegex(TypeError, 'the context manager', fooLacksEnterAndExit)
 
     def testExitAttributeError(self):
         class LacksExit(object):
@@ -136,7 +136,7 @@ class FailureTestCase(unittest.TestCase):
         def fooLacksExit():
             foo = LacksExit()
             with foo: pass
-        self.assertRaisesRegex(AttributeError, '__exit__', fooLacksExit)
+        self.assertRaisesRegex(TypeError, 'the context manager.*__exit__', fooLacksExit)
 
     def assertRaisesSyntaxError(self, codestr):
         def shouldRaiseSyntaxError(s):