Python test.support() Examples

def test_stderr_flush(self):
        # sys.stderr is flushed at process shutdown (issue #13812)
        if self.TYPE == "threads":
            self.skipTest('test not appropriate for {}'.format(self.TYPE))

        testfn = test.support.TESTFN
        self.addCleanup(test.support.unlink, testfn)
        proc = self.Process(target=self._test_stderr_flush, args=(testfn,))
        proc.start()
        proc.join()
        with open(testfn, 'r') as f:
            err = f.read()
            # The whole traceback was printed
            self.assertIn("ZeroDivisionError", err)
            self.assertIn("test_multiprocessing.py", err)
            self.assertIn("1/0 # MARKER", err) 

def test_threads_join(self):
        # Non-daemon threads should be joined at subinterpreter shutdown
        # (issue #18808)
        r, w = os.pipe()
        self.addCleanup(os.close, r)
        self.addCleanup(os.close, w)
        code = r"""if 1:
            import os
            import threading
            import time

            def f():
                # Sleep a bit so that the thread is still running when
                # Py_EndInterpreter is called.
                time.sleep(0.05)
                os.write(%d, b"x")
            threading.Thread(target=f).start()
            """ % (w,)
        ret = test.support.run_in_subinterp(code)
        self.assertEqual(ret, 0)
        # The thread was joined properly.
        self.assertEqual(os.read(r, 1), b"x") 

def test_daemon_threads_fatal_error(self):
        subinterp_code = r"""if 1:
            import os
            import threading
            import time

            def f():
                # Make sure the daemon thread is still running when
                # Py_EndInterpreter is called.
                time.sleep(10)
            threading.Thread(target=f, daemon=True).start()
            """
        script = r"""if 1:
            import _testcapi

            _testcapi.run_in_subinterp(%r)
            """ % (subinterp_code,)
        with test.support.SuppressCrashReport():
            rc, out, err = assert_python_failure("-c", script)
        self.assertIn("Fatal Python error: Py_EndInterpreter: "
                      "not the last thread", err.decode()) 

def test_pdb_issue4201(self):
        test_src = textwrap.dedent("""\
                    def f():
                        pass

                    import pdb
                    pdb.Pdb(nosigint=True).runcall(f)
                    """)
        with test.support.temp_dir() as d:
            script_name = make_script(d, 'script', test_src)
            p = spawn_python(script_name)
            p.stdin.write(b'l\n')
            data = kill_python(p)
            # bdb/pdb applies normcase to its filename before displaying
            self.assertIn(os.path.normcase(script_name.encode('utf-8')), data)
            zip_name, run_name = make_zip_script(d, "test_zip",
                                                script_name, '__main__.py')
            p = spawn_python(zip_name)
            p.stdin.write(b'l\n')
            data = kill_python(p)
            # bdb/pdb applies normcase to its filename before displaying
            self.assertIn(os.path.normcase(run_name.encode('utf-8')), data) 

def _run_object_doctest(obj, module):
    finder = doctest.DocTestFinder(verbose=verbose, recurse=False)
    runner = doctest.DocTestRunner(verbose=verbose)
    # Use the object's fully qualified name if it has one
    # Otherwise, use the module's name
    try:
        name = "%s.%s" % (obj.__module__, obj.__qualname__)
    except AttributeError:
        name = module.__name__
    for example in finder.find(obj, name, module):
        runner.run(example)
    f, t = runner.failures, runner.tries
    if f:
        raise test.support.TestFailed("%d of %d doctests failed" % (f, t))
    if verbose:
        print ('doctest (%s) ... %d tests with zero failures' % (module.__name__, t))
    return f, t 

def test_issue22668(self):
        a = array.array('H', [256, 256, 256, 256])
        x = memoryview(a)
        m = x.cast('B')
        b = m.cast('H')
        c = b[0:2]
        d = memoryview(b)

        del b

        self.assertEqual(c[0], 256)
        self.assertEqual(d[0], 256)
        self.assertEqual(c.format, "H")
        self.assertEqual(d.format, "H")

        _ = m.cast('I')
        self.assertEqual(c[0], 256)
        self.assertEqual(d[0], 256)
        self.assertEqual(c.format, "H")
        self.assertEqual(d.format, "H")


# Variations on source objects for the buffer: bytes-like objects, then arrays
# with itemsize > 1.
# NOTE: support for multi-dimensional objects is unimplemented. 

def test_ctypes_cast(self):
        # Issue 15944: Allow all source formats when casting to bytes.
        ctypes = test.support.import_module("ctypes")
        p6 = bytes(ctypes.c_double(0.6))

        d = ctypes.c_double()
        m = memoryview(d).cast("B")
        m[:2] = p6[:2]
        m[2:] = p6[2:]
        self.assertEqual(d.value, 0.6)

        for format in "Bbc":
            with self.subTest(format):
                d = ctypes.c_double()
                m = memoryview(d).cast(format)
                m[:2] = memoryview(p6).cast(format)[:2]
                m[2:] = memoryview(p6).cast(format)[2:]
                self.assertEqual(d.value, 0.6) 

def test_recursionlimit_fatalerror(self):
        # A fatal error occurs if a second recursion limit is hit when recovering
        # from a first one.
        code = textwrap.dedent("""
            import sys

            def f():
                try:
                    f()
                except RecursionError:
                    f()

            sys.setrecursionlimit(%d)
            f()""")
        with test.support.SuppressCrashReport():
            for i in (50, 1000):
                sub = subprocess.Popen([sys.executable, '-c', code % i],
                    stderr=subprocess.PIPE)
                err = sub.communicate()[1]
                self.assertTrue(sub.returncode, sub.returncode)
                self.assertIn(
                    b"Fatal Python error: Cannot recover from stack overflow",
                    err) 

def test_pythontypes(self):
        # check all types defined in Python/
        size = test.support.calcobjsize
        vsize = test.support.calcvobjsize
        check = self.check_sizeof
        # _ast.AST
        import _ast
        check(_ast.AST(), size('P'))
        try:
            raise TypeError
        except TypeError:
            tb = sys.exc_info()[2]
            # traceback
            if tb is not None:
                check(tb, size('2P2i'))
        # symtable entry
        # XXX
        # sys.flags
        check(sys.flags, vsize('') + self.P * len(sys.flags)) 

def check_enough_semaphores():
    """Check that the system supports enough semaphores to run the test."""
    # minimum number of semaphores available according to POSIX
    nsems_min = 256
    try:
        nsems = os.sysconf("SC_SEM_NSEMS_MAX")
    except (AttributeError, ValueError):
        # sysconf not available or setting not available
        return
    if nsems == -1 or nsems >= nsems_min:
        return
    raise unittest.SkipTest("The OS doesn't support enough semaphores "
                            "to run the test (required: %d)." % nsems_min)


#
# Creates a wrapper for a function which records the time it takes to finish
# 

def test_no_import_lock_contention(self):
        with test.support.temp_cwd():
            module_name = 'imported_by_an_imported_module'
            with open(module_name + '.py', 'w') as f:
                f.write("""if 1:
                    import multiprocessing

                    q = multiprocessing.Queue()
                    q.put('knock knock')
                    q.get(timeout=3)
                    q.close()
                    del q
                """)

            with test.support.DirsOnSysPath(os.getcwd()):
                try:
                    __import__(module_name)
                except pyqueue.Empty:
                    self.fail("Probable regression on import lock contention;"
                              " see Issue #22853") 

def test_traceback(self):
        # We want ensure that the traceback from the child process is
        # contained in the traceback raised in the main process.
        if self.TYPE == 'processes':
            with self.Pool(1) as p:
                try:
                    p.apply(self._test_traceback)
                except Exception as e:
                    exc = e
                else:
                    raise AssertionError('expected RuntimeError')
            self.assertIs(type(exc), RuntimeError)
            self.assertEqual(exc.args, (123,))
            cause = exc.__cause__
            self.assertIs(type(cause), multiprocessing.pool.RemoteTraceback)
            self.assertIn('raise RuntimeError(123) # some comment', cause.tb)

            with test.support.captured_stderr() as f1:
                try:
                    raise exc
                except RuntimeError:
                    sys.excepthook(*sys.exc_info())
            self.assertIn('raise RuntimeError(123) # some comment',
                          f1.getvalue()) 

def _listener(cls, conn, families):
        for fam in families:
            l = cls.connection.Listener(family=fam)
            conn.send(l.address)
            new_conn = l.accept()
            conn.send(new_conn)
            new_conn.close()
            l.close()

        l = socket.socket()
        l.bind((test.support.HOST, 0))
        l.listen()
        conn.send(l.getsockname())
        new_conn, addr = l.accept()
        conn.send(new_conn)
        new_conn.close()
        l.close()

        conn.recv() 

def test_threads_join(self):
        # Non-daemon threads should be joined at subinterpreter shutdown
        # (issue #18808)
        r, w = os.pipe()
        self.addCleanup(os.close, r)
        self.addCleanup(os.close, w)
        code = r"""if 1:
            import os
            import threading
            import time

            def f():
                # Sleep a bit so that the thread is still running when
                # Py_EndInterpreter is called.
                time.sleep(0.05)
                os.write(%d, b"x")
            threading.Thread(target=f).start()
            """ % (w,)
        ret = test.support.run_in_subinterp(code)
        self.assertEqual(ret, 0)
        # The thread was joined properly.
        self.assertEqual(os.read(r, 1), b"x") 

def test_daemon_threads_fatal_error(self):
        subinterp_code = r"""if 1:
            import os
            import threading
            import time

            def f():
                # Make sure the daemon thread is still running when
                # Py_EndInterpreter is called.
                time.sleep(10)
            threading.Thread(target=f, daemon=True).start()
            """
        script = r"""if 1:
            import _testcapi

            _testcapi.run_in_subinterp(%r)
            """ % (subinterp_code,)
        with test.support.SuppressCrashReport():
            rc, out, err = assert_python_failure("-c", script)
        self.assertIn("Fatal Python error: Py_EndInterpreter: "
                      "not the last thread", err.decode()) 

def test_stderr_flush(self):
        # sys.stderr is flushed at process shutdown (issue #13812)
        if self.TYPE == "threads":
            self.skipTest('test not appropriate for {}'.format(self.TYPE))

        testfn = test.support.TESTFN
        self.addCleanup(test.support.unlink, testfn)
        proc = self.Process(target=self._test_stderr_flush, args=(testfn,))
        proc.start()
        proc.join()
        with open(testfn, 'r') as f:
            err = f.read()
            # The whole traceback was printed
            self.assertIn("ZeroDivisionError", err)
            self.assertIn("test_multiprocessing.py", err)
            self.assertIn("1/0 # MARKER", err) 

def _run_object_doctest(obj, module):
    finder = doctest.DocTestFinder(verbose=verbose, recurse=False)
    runner = doctest.DocTestRunner(verbose=verbose)
    # Use the object's fully qualified name if it has one
    # Otherwise, use the module's name
    try:
        name = "%s.%s" % (obj.__module__, obj.__name__)
    except AttributeError:
        name = module.__name__
    for example in finder.find(obj, name, module):
        runner.run(example)
    f, t = runner.failures, runner.tries
    if f:
        raise test.support.TestFailed("%d of %d doctests failed" % (f, t))
    if verbose:
        print ('doctest (%s) ... %d tests with zero failures' % (module.__name__, t))
    return f, t 

def test_recursionlimit_fatalerror(self):
        # A fatal error occurs if a second recursion limit is hit when recovering
        # from a first one.
        code = textwrap.dedent("""
            import sys

            def f():
                try:
                    f()
                except RuntimeError:
                    f()

            sys.setrecursionlimit(%d)
            f()""")
        with test.support.SuppressCrashReport():
            for i in (50, 1000):
                sub = subprocess.Popen([sys.executable, '-c', code % i],
                    stderr=subprocess.PIPE)
                err = sub.communicate()[1]
                self.assertTrue(sub.returncode, sub.returncode)
                self.assertIn(
                    b"Fatal Python error: Cannot recover from stack overflow",
                    err) 

def test_pythontypes(self):
        # check all types defined in Python/
        size = test.support.calcobjsize
        vsize = test.support.calcvobjsize
        check = self.check_sizeof
        # _ast.AST
        import _ast
        check(_ast.AST(), size('P'))
        try:
            raise TypeError
        except TypeError:
            tb = sys.exc_info()[2]
            # traceback
            if tb is not None:
                check(tb, size('2P2i'))
        # symtable entry
        # XXX
        # sys.flags
        check(sys.flags, vsize('') + self.P * len(sys.flags)) 

def test_fd_transfer(self):
        if self.TYPE != 'processes':
            self.skipTest("only makes sense with processes")
        conn, child_conn = self.Pipe(duplex=True)

        p = self.Process(target=self._writefd, args=(child_conn, b"foo"))
        p.daemon = True
        p.start()
        self.addCleanup(test.support.unlink, test.support.TESTFN)
        with open(test.support.TESTFN, "wb") as f:
            fd = f.fileno()
            if msvcrt:
                fd = msvcrt.get_osfhandle(fd)
            reduction.send_handle(conn, fd, p.pid)
        p.join()
        with open(test.support.TESTFN, "rb") as f:
            self.assertEqual(f.read(), b"foo") 

def tearDown(self):
        test.support.threading_cleanup(*self._threads)
        test.support.reap_children() 

def setUp(self):
        self.maxDiff = None
        self.prog_name = 'bogus_program_xxxx'
        self.temp_path_dir = os.path.abspath(os.getcwd())
        self.env = test.support.EnvironmentVarGuard()
        self.addCleanup(self.env.__exit__)
        for cv in ('CFLAGS', 'LDFLAGS', 'CPPFLAGS',
                            'BASECFLAGS', 'BLDSHARED', 'LDSHARED', 'CC',
                            'CXX', 'PY_CFLAGS', 'PY_LDFLAGS', 'PY_CPPFLAGS',
                            'PY_CORE_CFLAGS'):
            if cv in self.env:
                self.env.unset(cv) 

def test_various_ops_large_stack(self):
        if verbose:
            print('with 1MB thread stack size...')
        try:
            threading.stack_size(0x100000)
        except _thread.error:
            raise unittest.SkipTest(
                'platform does not support changing thread stack size')
        self.test_various_ops()
        threading.stack_size(0) 

def test_various_ops_small_stack(self):
        if verbose:
            print('with 256kB thread stack size...')
        try:
            threading.stack_size(262144)
        except _thread.error:
            raise unittest.SkipTest(
                'platform does not support changing thread stack size')
        self.test_various_ops()
        threading.stack_size(0)

    # run with a large thread stack size (1MB) 

def test_main():
    if sys.platform == 'darwin':
        test.support.run_unittest(Test_OSXSupport) 

def test_various_ops_large_stack(self):
        if verbose:
            print('with 1MB thread stack size...')
        try:
            threading.stack_size(0x100000)
        except _thread.error:
            raise unittest.SkipTest(
                'platform does not support changing thread stack size')
        self.test_various_ops()
        threading.stack_size(0) 

def test_main():
    test.support.run_unittest(ZipSupportTests)
    test.support.reap_children() 

def test_compare(self):
        # memoryviews can compare for equality with other objects
        # having the buffer interface.
        for tp in self._types:
            m = self._view(tp(self._source))
            for tp_comp in self._types:
                self.assertTrue(m == tp_comp(b"abcdef"))
                self.assertFalse(m != tp_comp(b"abcdef"))
                self.assertFalse(m == tp_comp(b"abcde"))
                self.assertTrue(m != tp_comp(b"abcde"))
                self.assertFalse(m == tp_comp(b"abcde1"))
                self.assertTrue(m != tp_comp(b"abcde1"))
            self.assertTrue(m == m)
            self.assertTrue(m == m[:])
            self.assertTrue(m[0:6] == m[:])
            self.assertFalse(m[0:5] == m)

            # Comparison with objects which don't support the buffer API
            self.assertFalse(m == "abcdef")
            self.assertTrue(m != "abcdef")
            self.assertFalse("abcdef" == m)
            self.assertTrue("abcdef" != m)

            # Unordered comparisons
            for c in (m, b"abcdef"):
                self.assertRaises(TypeError, lambda: m < c)
                self.assertRaises(TypeError, lambda: c <= m)
                self.assertRaises(TypeError, lambda: m >= c)
                self.assertRaises(TypeError, lambda: c > m) 

def test_weakref(self):
        # Check memoryviews are weakrefable
        for tp in self._types:
            b = tp(self._source)
            m = self._view(b)
            L = []
            def callback(wr, b=b):
                L.append(b)
            wr = weakref.ref(m, callback)
            self.assertIs(wr(), m)
            del m
            test.support.gc_collect()
            self.assertIs(wr(), None)
            self.assertIs(L[0], b) 

def test__find_executable(self):
        if self.env['PATH']:
            self.env['PATH'] = self.env['PATH'] + ':'
        self.env['PATH'] = self.env['PATH'] + os.path.abspath(self.temp_path_dir)
        test.support.unlink(self.prog_name)
        self.assertIsNone(_osx_support._find_executable(self.prog_name))
        self.addCleanup(test.support.unlink, self.prog_name)
        with open(self.prog_name, 'w') as f:
            f.write("#!/bin/sh\n/bin/echo OK\n")
        os.chmod(self.prog_name, stat.S_IRWXU)
        self.assertEqual(self.prog_name,
                            _osx_support._find_executable(self.prog_name))