gh-157242: Use support.inject_memory_error_cm() in tests (#157811)

Rename support.memory_error_cm() to support.inject_memory_error_cm().

(cherry picked from commit a92e0f9)

Author: vstinner

Lib/test/support/__init__.py

@@ -3472,7 +3472,7 @@ def inject_memory_error(start=0, stop=0):
 
 
 @contextlib.contextmanager
-def memory_error_cm(start=0, stop=0):
+def inject_memory_error_cm(start=0, stop=0):
     """
     Similar to inject_memory_error() but can be used as a context manager.
 

Lib/test/test_bytes.py

@@ -53,7 +53,7 @@ def __index__(self):
 @contextlib.contextmanager
 def inject_memory_error(testcase, start=0):
     with testcase.assertRaises(MemoryError):
-        with support.memory_error_cm(start):
+        with support.inject_memory_error_cm(start):
             yield
 
 

Lib/test/test_capi/test_bytes.py

@@ -455,6 +455,23 @@ def test_resize(self):
                     writer.resize(_testcapi.PY_SSIZE_T_MAX)
                 self.assertEqual(writer.finish(), b'x' * size)
 
+    @support.nomemtest
+    def test_resize_error(self):
+        # Test PyBytesWriter_Resize() error
+        init = b'x' * self.LARGE_BUFFER
+        writer = self.create_writer(len(init))
+        writer.write(0, init)
+        size = len(init) + 100
+        with self.assertRaises(MemoryError):
+            with support.inject_memory_error_cm():
+                writer.resize(size)
+        suffix = b'still working'
+        writer.write_bytes(suffix, -1)
+        self.assertEqual(writer.finish(), init + suffix)
+
+        # Note: PyBytesWriter_Resize() leaves the buffer unchanged (no resize)
+        # if the new size is smaller than the allocated size
+
     def test_grow(self):
         # Test PyBytesWriter_Grow()
         writer = self.create_writer(0)
@@ -513,24 +530,20 @@ def test_grow(self):
                 self.assertEqual(writer.finish(), b'x' * size)
 
     @support.nomemtest
-    def test_resize_error(self):
-        # Test PyBytesWriter_Resize() error
+    def test_grow_error(self):
+        # Test PyBytesWriter_Grow() error
         init = b'x' * self.LARGE_BUFFER
         writer = self.create_writer(len(init))
         writer.write(0, init)
-        size = len(init) + 100
-        try:
-            with self.assertRaises(MemoryError):
-                _testcapi.set_nomemory(0)
-                writer.resize(size)
-        finally:
-            _testcapi.remove_mem_hooks()
+        with self.assertRaises(MemoryError):
+            with support.inject_memory_error_cm():
+                writer.grow(100)
         suffix = b'still working'
         writer.write_bytes(suffix, -1)
         self.bytes_equal(writer.finish(), init + suffix)
 
-        # Note: PyBytesWriter_Resize() leaves the buffer unchanged (no resize)
-        # if the new size is smaller than the allocated size
+        # Note: PyBytesWriter_Grow() leaves the buffer unchanged (no resize)
+        # if grow is negative.
 
     def test_format_i(self):
         # Test PyBytesWriter_Format()

Lib/test/test_class.py

@@ -1030,7 +1030,7 @@ def __init__(self):
             d = a.__dict__
             try:
                 with support.catch_unraisable_exception() as ex:
-                    with support.memory_error_cm(n, n + 1):
+                    with support.inject_memory_error_cm(n, n + 1):
                         del a
                     exc_type = ex.unraisable and ex.unraisable.exc_type
             except MemoryError:

Lib/test/test_interpreters/test_stress.py

@@ -78,15 +78,9 @@ def run():
 
     @support.nomemtest
     def test_create_interpreter_no_memory(self):
-        import _testcapi
-
-        assertion = self.assertRaises(InterpreterError)
-        try:
-            _testcapi.set_nomemory(0, 1)
-            with assertion:
+        with self.assertRaises(InterpreterError):
+            with support.inject_memory_error_cm(0, 1):
                 _interpreters.create()
-        finally:
-            _testcapi.remove_mem_hooks()
 
 
 if __name__ == '__main__':

Lib/test/test_io/test_memoryio.py

@@ -5,7 +5,6 @@
 
 import unittest
 from test import support
-from test.support import import_helper
 
 import gc
 import io
@@ -654,18 +653,14 @@ def __buffer__(self, flags):
 
     def test_memory_error(self):
         # gh-157242: io.BytesIO() must not close the file on MemoryError
-        _testcapi = import_helper.import_module('_testcapi')
 
         # write()
         stream = self.ioclass()
         stream.write(self.buftype('abc'))
+        data = self.buftype('def')
         with self.assertRaises(MemoryError):
-            try:
-                data = self.buftype('def')
-                _testcapi.set_nomemory(0)
+            with support.inject_memory_error_cm():
                 stream.write(data)
-            finally:
-                _testcapi.remove_mem_hooks()
         stream.write(self.buftype('123'))
         self.assertEqual(stream.getvalue(), self.buftype('abc123'))
 
@@ -674,11 +669,8 @@ def test_memory_error(self):
         stream = self.ioclass()
         stream.write(data)
         with self.assertRaises(MemoryError):
-            try:
-                _testcapi.set_nomemory(0)
+            with support.inject_memory_error_cm():
                 stream.truncate(5)
-            finally:
-                _testcapi.remove_mem_hooks()
         self.assertEqual(stream.getvalue(), data)
 
 

Lib/test/test_pyexpat.py

@@ -1029,7 +1029,7 @@ def test_error_path_no_crash(self):
         rc_before = sys.getrefcount(parser)
 
         with self.assertRaises(MemoryError):
-            with support.memory_error_cm(1, 10):
+            with support.inject_memory_error_cm(1, 10):
                 parser.ExternalEntityParserCreate(None)
 
         rc_after = sys.getrefcount(parser)

Lib/test/test_str.py

@@ -614,7 +614,7 @@ def test_replace_oom(self):
         s2 = "&"
         s3 = "&"
         with self.assertRaises(MemoryError):
-            with support.memory_error_cm():
+            with support.inject_memory_error_cm():
                 s1.replace(s2, s3)  # this line used to crash before
 
     def test_repeat_id_preserving(self):