cpython/Lib/test/test_support.py

import contextlib
import errno
import importlib
import io
import os
import shutil
import socket
import stat
import sys
import tempfile
import time
import unittest
from test import support

TESTFN = support.TESTFN


class TestSupport(unittest.TestCase):

    def test_import_module(self):
        support.import_module("ftplib")
        self.assertRaises(unittest.SkipTest, support.import_module, "foo")

    def test_import_fresh_module(self):
        support.import_fresh_module("ftplib")

    def test_get_attribute(self):
        self.assertEqual(support.get_attribute(self, "test_get_attribute"),
                        self.test_get_attribute)
        self.assertRaises(unittest.SkipTest, support.get_attribute, self, "foo")

    @unittest.skip("failing buildbots")
    def test_get_original_stdout(self):
        self.assertEqual(support.get_original_stdout(), sys.stdout)

    def test_unload(self):
        import sched
        self.assertIn("sched", sys.modules)
        support.unload("sched")
        self.assertNotIn("sched", sys.modules)

    def test_unlink(self):
        with open(TESTFN, "w") as f:
            pass
        support.unlink(TESTFN)
        self.assertFalse(os.path.exists(TESTFN))
        support.unlink(TESTFN)

    def test_rmtree(self):
        dirpath = support.TESTFN + 'd'
        subdirpath = os.path.join(dirpath, 'subdir')
        os.mkdir(dirpath)
        os.mkdir(subdirpath)
        support.rmtree(dirpath)
        self.assertFalse(os.path.exists(dirpath))
        with support.swap_attr(support, 'verbose', 0):
            support.rmtree(dirpath)

        os.mkdir(dirpath)
        os.mkdir(subdirpath)
        os.chmod(dirpath, stat.S_IRUSR|stat.S_IXUSR)
        with support.swap_attr(support, 'verbose', 0):
            support.rmtree(dirpath)
        self.assertFalse(os.path.exists(dirpath))

        os.mkdir(dirpath)
        os.mkdir(subdirpath)
        os.chmod(dirpath, 0)
        with support.swap_attr(support, 'verbose', 0):
            support.rmtree(dirpath)
        self.assertFalse(os.path.exists(dirpath))

    def test_forget(self):
        mod_filename = TESTFN + '.py'
        with open(mod_filename, 'w') as f:
            print('foo = 1', file=f)
        sys.path.insert(0, os.curdir)
        importlib.invalidate_caches()
        try:
            mod = __import__(TESTFN)
            self.assertIn(TESTFN, sys.modules)

            support.forget(TESTFN)
            self.assertNotIn(TESTFN, sys.modules)
        finally:
            del sys.path[0]
            support.unlink(mod_filename)
            support.rmtree('__pycache__')

    def test_HOST(self):
        s = socket.socket()
        s.bind((support.HOST, 0))
        s.close()

    def test_find_unused_port(self):
        port = support.find_unused_port()
        s = socket.socket()
        s.bind((support.HOST, port))
        s.close()

    def test_bind_port(self):
        s = socket.socket()
        support.bind_port(s)
        s.listen()
        s.close()

    # Tests for temp_dir()

    def test_temp_dir(self):
        """Test that temp_dir() creates and destroys its directory."""
        parent_dir = tempfile.mkdtemp()
        parent_dir = os.path.realpath(parent_dir)

        try:
            path = os.path.join(parent_dir, 'temp')
            self.assertFalse(os.path.isdir(path))
            with support.temp_dir(path) as temp_path:
                self.assertEqual(temp_path, path)
                self.assertTrue(os.path.isdir(path))
            self.assertFalse(os.path.isdir(path))
        finally:
            support.rmtree(parent_dir)

    def test_temp_dir__path_none(self):
        """Test passing no path."""
        with support.temp_dir() as temp_path:
            self.assertTrue(os.path.isdir(temp_path))
        self.assertFalse(os.path.isdir(temp_path))

    def test_temp_dir__existing_dir__quiet_default(self):
        """Test passing a directory that already exists."""
        def call_temp_dir(path):
            with support.temp_dir(path) as temp_path:
                raise Exception("should not get here")

        path = tempfile.mkdtemp()
        path = os.path.realpath(path)
        try:
            self.assertTrue(os.path.isdir(path))
            self.assertRaises(FileExistsError, call_temp_dir, path)
            # Make sure temp_dir did not delete the original directory.
            self.assertTrue(os.path.isdir(path))
        finally:
            shutil.rmtree(path)

    def test_temp_dir__existing_dir__quiet_true(self):
        """Test passing a directory that already exists with quiet=True."""
        path = tempfile.mkdtemp()
        path = os.path.realpath(path)

        try:
            with support.check_warnings() as recorder:
                with support.temp_dir(path, quiet=True) as temp_path:
                    self.assertEqual(path, temp_path)
                warnings = [str(w.message) for w in recorder.warnings]
            # Make sure temp_dir did not delete the original directory.
            self.assertTrue(os.path.isdir(path))
        finally:
            shutil.rmtree(path)

        self.assertEqual(len(warnings), 1, warnings)
        warn = warnings[0]
        self.assertTrue(warn.startswith(f'tests may fail, unable to create '
                                        f'temporary directory {path!r}: '),
                        warn)

    # Tests for change_cwd()

    def test_change_cwd(self):
        original_cwd = os.getcwd()

        with support.temp_dir() as temp_path:
            with support.change_cwd(temp_path) as new_cwd:
                self.assertEqual(new_cwd, temp_path)
                self.assertEqual(os.getcwd(), new_cwd)

        self.assertEqual(os.getcwd(), original_cwd)

    def test_change_cwd__non_existent_dir(self):
        """Test passing a non-existent directory."""
        original_cwd = os.getcwd()

        def call_change_cwd(path):
            with support.change_cwd(path) as new_cwd:
                raise Exception("should not get here")

        with support.temp_dir() as parent_dir:
            non_existent_dir = os.path.join(parent_dir, 'does_not_exist')
            self.assertRaises(FileNotFoundError, call_change_cwd,
                              non_existent_dir)

        self.assertEqual(os.getcwd(), original_cwd)

    def test_change_cwd__non_existent_dir__quiet_true(self):
        """Test passing a non-existent directory with quiet=True."""
        original_cwd = os.getcwd()

        with support.temp_dir() as parent_dir:
            bad_dir = os.path.join(parent_dir, 'does_not_exist')
            with support.check_warnings() as recorder:
                with support.change_cwd(bad_dir, quiet=True) as new_cwd:
                    self.assertEqual(new_cwd, original_cwd)
                    self.assertEqual(os.getcwd(), new_cwd)
                warnings = [str(w.message) for w in recorder.warnings]

        self.assertEqual(len(warnings), 1, warnings)
        warn = warnings[0]
        self.assertTrue(warn.startswith(f'tests may fail, unable to change '
                                        f'the current working directory '
                                        f'to {bad_dir!r}: '),
                        warn)

    # Tests for change_cwd()

    def test_change_cwd__chdir_warning(self):
        """Check the warning message when os.chdir() fails."""
        path = TESTFN + '_does_not_exist'
        with support.check_warnings() as recorder:
            with support.change_cwd(path=path, quiet=True):
                pass
            messages = [str(w.message) for w in recorder.warnings]

        self.assertEqual(len(messages), 1, messages)
        msg = messages[0]
        self.assertTrue(msg.startswith(f'tests may fail, unable to change '
                                       f'the current working directory '
                                       f'to {path!r}: '),
                        msg)

    # Tests for temp_cwd()

    def test_temp_cwd(self):
        here = os.getcwd()
        with support.temp_cwd(name=TESTFN):
            self.assertEqual(os.path.basename(os.getcwd()), TESTFN)
        self.assertFalse(os.path.exists(TESTFN))
        self.assertTrue(os.path.basename(os.getcwd()), here)


    def test_temp_cwd__name_none(self):
        """Test passing None to temp_cwd()."""
        original_cwd = os.getcwd()
        with support.temp_cwd(name=None) as new_cwd:
            self.assertNotEqual(new_cwd, original_cwd)
            self.assertTrue(os.path.isdir(new_cwd))
            self.assertEqual(os.getcwd(), new_cwd)
        self.assertEqual(os.getcwd(), original_cwd)

    def test_sortdict(self):
        self.assertEqual(support.sortdict({3:3, 2:2, 1:1}), "{1: 1, 2: 2, 3: 3}")

    def test_make_bad_fd(self):
        fd = support.make_bad_fd()
        with self.assertRaises(OSError) as cm:
            os.write(fd, b"foo")
        self.assertEqual(cm.exception.errno, errno.EBADF)

    def test_check_syntax_error(self):
        support.check_syntax_error(self, "def class", lineno=1, offset=9)
        with self.assertRaises(AssertionError):
            support.check_syntax_error(self, "x=1")

    def test_CleanImport(self):
        import importlib
        with support.CleanImport("asyncore"):
            importlib.import_module("asyncore")

    def test_DirsOnSysPath(self):
        with support.DirsOnSysPath('foo', 'bar'):
            self.assertIn("foo", sys.path)
            self.assertIn("bar", sys.path)
        self.assertNotIn("foo", sys.path)
        self.assertNotIn("bar", sys.path)

    def test_captured_stdout(self):
        with support.captured_stdout() as stdout:
            print("hello")
        self.assertEqual(stdout.getvalue(), "hello\n")

    def test_captured_stderr(self):
        with support.captured_stderr() as stderr:
            print("hello", file=sys.stderr)
        self.assertEqual(stderr.getvalue(), "hello\n")

    def test_captured_stdin(self):
        with support.captured_stdin() as stdin:
            stdin.write('hello\n')
            stdin.seek(0)
            # call test code that consumes from sys.stdin
            captured = input()
        self.assertEqual(captured, "hello")

    def test_gc_collect(self):
        support.gc_collect()

    def test_python_is_optimized(self):
        self.assertIsInstance(support.python_is_optimized(), bool)

    def test_swap_attr(self):
        class Obj:
            pass
        obj = Obj()
        obj.x = 1
        with support.swap_attr(obj, "x", 5) as x:
            self.assertEqual(obj.x, 5)
            self.assertEqual(x, 1)
        self.assertEqual(obj.x, 1)
        with support.swap_attr(obj, "y", 5) as y:
            self.assertEqual(obj.y, 5)
            self.assertIsNone(y)
        self.assertFalse(hasattr(obj, 'y'))
        with support.swap_attr(obj, "y", 5):
            del obj.y
        self.assertFalse(hasattr(obj, 'y'))

    def test_swap_item(self):
        D = {"x":1}
        with support.swap_item(D, "x", 5) as x:
            self.assertEqual(D["x"], 5)
            self.assertEqual(x, 1)
        self.assertEqual(D["x"], 1)
        with support.swap_item(D, "y", 5) as y:
            self.assertEqual(D["y"], 5)
            self.assertIsNone(y)
        self.assertNotIn("y", D)
        with support.swap_item(D, "y", 5):
            del D["y"]
        self.assertNotIn("y", D)

    class RefClass:
        attribute1 = None
        attribute2 = None
        _hidden_attribute1 = None
        __magic_1__ = None

    class OtherClass:
        attribute2 = None
        attribute3 = None
        __magic_1__ = None
        __magic_2__ = None

    def test_detect_api_mismatch(self):
        missing_items = support.detect_api_mismatch(self.RefClass,
                                                    self.OtherClass)
        self.assertEqual({'attribute1'}, missing_items)

        missing_items = support.detect_api_mismatch(self.OtherClass,
                                                    self.RefClass)
        self.assertEqual({'attribute3', '__magic_2__'}, missing_items)

    def test_detect_api_mismatch__ignore(self):
        ignore = ['attribute1', 'attribute3', '__magic_2__', 'not_in_either']

        missing_items = support.detect_api_mismatch(
                self.RefClass, self.OtherClass, ignore=ignore)
        self.assertEqual(set(), missing_items)

        missing_items = support.detect_api_mismatch(
                self.OtherClass, self.RefClass, ignore=ignore)
        self.assertEqual(set(), missing_items)

    def test_check__all__(self):
        extra = {'tempdir'}
        blacklist = {'template'}
        support.check__all__(self,
                             tempfile,
                             extra=extra,
                             blacklist=blacklist)

        extra = {'TextTestResult', 'installHandler'}
        blacklist = {'load_tests', "TestProgram", "BaseTestSuite"}

        support.check__all__(self,
                             unittest,
                             ("unittest.result", "unittest.case",
                              "unittest.suite", "unittest.loader",
                              "unittest.main", "unittest.runner",
                              "unittest.signals"),
                             extra=extra,
                             blacklist=blacklist)

        self.assertRaises(AssertionError, support.check__all__, self, unittest)

    @unittest.skipUnless(hasattr(os, 'waitpid') and hasattr(os, 'WNOHANG'),
                         'need os.waitpid() and os.WNOHANG')
    def test_reap_children(self):
        # Make sure that there is no other pending child process
        support.reap_children()

        # Create a child process
        pid = os.fork()
        if pid == 0:
            # child process: do nothing, just exit
            os._exit(0)

        t0 = time.monotonic()
        deadline = time.monotonic() + 60.0

        was_altered = support.environment_altered
        try:
            support.environment_altered = False
            stderr = io.StringIO()

            while True:
                if time.monotonic() > deadline:
                    self.fail("timeout")

                with contextlib.redirect_stderr(stderr):
                    support.reap_children()

                # Use environment_altered to check if reap_children() found
                # the child process
                if support.environment_altered:
                    break

                # loop until the child process completed
                time.sleep(0.100)

            msg = "Warning -- reap_children() reaped child process %s" % pid
            self.assertIn(msg, stderr.getvalue())
            self.assertTrue(support.environment_altered)
        finally:
            support.environment_altered = was_altered

        # Just in case, check again that there is no other
        # pending child process
        support.reap_children()

    # XXX -follows a list of untested API
    # make_legacy_pyc
    # is_resource_enabled
    # requires
    # fcmp
    # umaks
    # findfile
    # check_warnings
    # EnvironmentVarGuard
    # TransientResource
    # transient_internet
    # run_with_locale
    # set_memlimit
    # bigmemtest
    # precisionbigmemtest
    # bigaddrspacetest
    # requires_resource
    # run_doctest
    # threading_cleanup
    # reap_threads
    # strip_python_stderr
    # args_from_interpreter_flags
    # can_symlink
    # skip_unless_symlink
    # SuppressCrashReport


def test_main():
    tests = [TestSupport]
    support.run_unittest(*tests)

if __name__ == '__main__':
    test_main()