Add tests for faulthandler

Author: sergey-miryanov

Lib/test/test_sys_getattr.py

@@ -1,3 +1,5 @@
+from pathlib import Path
+import tempfile
 import test.support
 from test.support.script_helper import assert_python_failure, assert_python_ok
 import textwrap
@@ -9,10 +11,44 @@
 @test.support.cpython_only
 class PySysGetAttrTest(unittest.TestCase):
 
+    common_faulthandler_code = textwrap.dedent('''
+        from contextlib import redirect_stderr
+        from threading import Thread
+        import time
+        from faulthandler import dump_traceback, enable, dump_traceback_later
 
-    def test_changing_stdout_from_thread(self):
+        class FakeFile:
+            def __init__(self):
+                self.f = open("{0}", "w")
+            def write(self, s):
+                self.f.write(s)
+            def flush(self):
+                time.sleep(0.2)
+            def fileno(self):
+                time.sleep(0.2)
+                return self.f.fileno()
+
+        def thread1():
+            text = FakeFile()
+            with redirect_stderr(text):
+                time.sleep(0.2)
+
+        def main():
+            enable(None, True)
+            t1 = Thread(target=thread1, args=())
+            t1.start()
+            time.sleep(0.1)
+            {1}
+
+        if __name__ == "__main__":
+            main()
+    ''')
+
+
+    def test_print_deleted_stdout(self):
         # print should use strong reference to the stdout.
         code = textwrap.dedent('''
+            # from https://gist.github.com/colesbury/c48f50e95d5d68e24814a56e2664e587
             from contextlib import redirect_stdout
             from io import StringIO
             from threading import Thread
@@ -23,7 +59,6 @@ def __repr__(self):
                     time.sleep(0.2)
                     return "Foo"
 
-
             def thread1():
                 text = StringIO()
                 with redirect_stdout(text):
@@ -43,5 +78,41 @@ def main():
         self.assertEqual(out, b"")
         self.assertEqual(err, b"")
 
+    def test_faulthandler_enable_deleted_stderr(self):
+        # faulthandler should use strong reference to the stderr
+        with tempfile.TemporaryDirectory() as tmpdir:
+            path = Path(tmpdir, "test_faulthandler_enable")
+            test_code = self.common_faulthandler_code.format(
+                path.as_posix(),
+                "enable(None, True)"
+            )
+            rc, out, err = assert_python_ok('-c', test_code)
+            self.assertEqual(out, b"")
+            self.assertEqual(err, b"")
+
+    def test_faulthandler_dump_traceback_deleted_stderr(self):
+        # faulthandler should use strong reference to the stderr
+        with tempfile.TemporaryDirectory() as tmpdir:
+            path = Path(tmpdir, "test_faulthandler_dump_traceback")
+            test_code = self.common_faulthandler_code.format(
+                path.as_posix(),
+                "dump_traceback(None, False)"
+            )
+            rc, out, err = assert_python_ok('-c', test_code)
+            self.assertEqual(out, b"")
+            self.assertEqual(err, b"")
+
+    def test_faulthandler_dump_traceback_later_deleted_stderr(self):
+        # faulthandler should use strong reference to the stderr
+        with tempfile.TemporaryDirectory() as tmpdir:
+            path = Path(tmpdir, "test_faulthandler_dump_traceback_later")
+            test_code = self.common_faulthandler_code.format(
+                path.as_posix(),
+                "dump_traceback_later(0.1, True, None, False)"
+            )
+            rc, out, err = assert_python_ok('-c', test_code)
+            self.assertEqual(out, b"")
+            self.assertEqual(err, b"")
+
 if __name__ == "__main__":
     unittest.main()