Resolve test_exceptions nicer

python · erlend-aasland · Mar 4, 2024 · Mar 4, 2024 · Mar 4, 2024 · Mar 4, 2024
commit e877ffb04d45e6ddd77f75dcdaa2f17bda46ddbf
@@ -19,8 +19,10 @@
 from test import support
 
 try:
+    import _testcapi
     from _testcapi import INT_MAX
 except ImportError:
+    _testcapi = None
     INT_MAX = 2**31 - 1
 
 
@@ -344,8 +346,8 @@ def __init__(self_):
         class InvalidException:
             pass
 
+        @unittest.skipIf(_testcapi is None, "requires _testcapi")
         def test_capi1():
-            _testcapi = import_module("_testcapi")
             try:
                 _testcapi.raise_exception(BadException, 1)
             except TypeError as err:
@@ -355,8 +357,8 @@ def test_capi1():
             else:
                 self.fail("Expected exception")
 
+        @unittest.skipIf(_testcapi is None, "requires _testcapi")
         def test_capi2():
-            _testcapi = import_module("_testcapi")
             try:
                 _testcapi.raise_exception(BadException, 0)
             except RuntimeError as err:
@@ -369,8 +371,8 @@ def test_capi2():
             else:
                 self.fail("Expected exception")
 
+        @unittest.skipIf(_testcapi is None, "requires _testcapi")
         def test_capi3():
-            _testcapi = import_module("_testcapi")
             self.assertRaises(SystemError, _testcapi.raise_exception,
                               InvalidException, 1)
 
@@ -1435,8 +1437,8 @@ def gen():
         self.assertIn(b'Done.', out)
 
     @cpython_only
+    @unittest.skipIf(_testcapi is None, "requires _testcapi")
     def test_recursion_normalizing_infinite_exception(self):
-        import_module("_testcapi")
         # Issue #30697. Test that a RecursionError is raised when
         # maximum recursion depth has been exceeded when creating
         # an exception
@@ -1504,8 +1506,8 @@ def recurse_in_body_and_except():
     # Python built with Py_TRACE_REFS fail with a fatal error in
     # _PyRefchain_Trace() on memory allocation error.
     @unittest.skipIf(support.Py_TRACE_REFS, 'cannot test Py_TRACE_REFS build')
+    @unittest.skipIf(_testcapi is None, "requires _testcapi")
     def test_recursion_normalizing_with_no_memory(self):
-        import_module("_testcapi")
         # Issue #30697. Test that in the abort that occurs when there is no
         # memory left and the size of the Python frames stack is greater than
         # the size of the list of preallocated MemoryError instances, the
@@ -1527,14 +1529,15 @@ def recurse(cnt):
             self.assertIn(b'MemoryError', err)
 
     @cpython_only
+    @unittest.skipIf(_testcapi is None, "requires _testcapi")
     def test_MemoryError(self):
         # PyErr_NoMemory always raises the same exception instance.
         # Check that the traceback is not doubled.
-        _testcapi = import_module("_testcapi")
         import traceback
+        from _testcapi import raise_memoryerror
         def raiseMemError():
             try:
-                _testcapi.raise_memoryerror()
+                raise_memoryerror()
             except MemoryError as e:
                 tb = e.__traceback__
             else:
@@ -1546,8 +1549,8 @@ def raiseMemError():
         self.assertEqual(tb1, tb2)
 
     @cpython_only
+    @unittest.skipIf(_testcapi is None, "requires _testcapi")
     def test_exception_with_doc(self):
-        _testcapi = import_module("_testcapi")
         doc2 = "This is a test docstring."
         doc4 = "This is another test docstring."
 
@@ -1586,18 +1589,19 @@ class C(object):
         self.assertEqual(error5.__doc__, "")
 
     @cpython_only
+    @unittest.skipIf(_testcapi is None, "requires _testcapi")
     def test_memory_error_cleanup(self):
         # Issue #5437: preallocated MemoryError instances should not keep
         # traceback objects alive.
-        _testcapi = import_module("_testcapi")
+        from _testcapi import raise_memoryerror
         class C:
             pass
         wr = None
         def inner():
             nonlocal wr
             c = C()
             wr = weakref.ref(c)
-            _testcapi.raise_memoryerror()
+            raise_memoryerror()
         # We cannot use assertRaises since it manually deletes the traceback
         try:
             inner()
@@ -1676,8 +1680,8 @@ def test_unhandled(self):
     # Python built with Py_TRACE_REFS fail with a fatal error in
     # _PyRefchain_Trace() on memory allocation error.
     @unittest.skipIf(support.Py_TRACE_REFS, 'cannot test Py_TRACE_REFS build')
+    @unittest.skipIf(_testcapi is None, "requires _testcapi")
     def test_memory_error_in_PyErr_PrintEx(self):
-        import_module("_testcapi")
         code = """if 1:
             import _testcapi
             class C(): pass
@@ -1795,8 +1799,8 @@ class TestException(MemoryError):
 
             gc_collect()
 
+    @unittest.skipIf(_testcapi is None, "requires _testcapi")
     def test_memory_error_in_subinterp(self):
-        import_module("_testcapi")
         # gh-109894: subinterpreters shouldn't count on last resort memory error
         # when MemoryError is raised through PyErr_NoMemory() call,
         # and should preallocate memory errors as does the main interpreter.