[2.7] bpo-30283: Backport test_regrtest from master to 2.7 (#1513)

* bpo-30283: regrtest: add --testdir option

* bpo-30283: Backport _testcapi.raise_signal()

Function used by test_regrtest to simulate an interrupted unit test.

* bpo-30283: Backport test_regrtest from master
diff --git a/Lib/test/test_regrtest.py b/Lib/test/test_regrtest.py
new file mode 100644
index 0000000..9f68d6b
--- /dev/null
+++ b/Lib/test/test_regrtest.py
@@ -0,0 +1,425 @@
+"""
+Tests of regrtest.py.
+
+Note: test_regrtest cannot be run twice in parallel.
+"""
+from __future__ import print_function
+
+import collections
+import os.path
+import platform
+import re
+import subprocess
+import sys
+import sysconfig
+import tempfile
+import textwrap
+import unittest
+from test import support
+
+
+Py_DEBUG = hasattr(sys, 'getobjects')
+ROOT_DIR = os.path.join(os.path.dirname(__file__), '..', '..')
+ROOT_DIR = os.path.abspath(os.path.normpath(ROOT_DIR))
+
+TEST_INTERRUPTED = textwrap.dedent("""
+    from signal import SIGINT
+    try:
+        from _testcapi import raise_signal
+        raise_signal(SIGINT)
+    except ImportError:
+        import os
+        os.kill(os.getpid(), SIGINT)
+    """)
+
+
+SubprocssRun = collections.namedtuple('SubprocssRun', 'returncode stdout, stderr')
+
+
+class BaseTestCase(unittest.TestCase):
+    TEST_UNIQUE_ID = 1
+    TESTNAME_PREFIX = 'test_regrtest_'
+    TESTNAME_REGEX = r'test_[a-zA-Z0-9_]+'
+
+    def setUp(self):
+        self.testdir = os.path.realpath(os.path.dirname(__file__))
+
+        self.tmptestdir = tempfile.mkdtemp()
+        self.addCleanup(support.rmtree, self.tmptestdir)
+
+    def create_test(self, name=None, code=''):
+        if not name:
+            name = 'noop%s' % BaseTestCase.TEST_UNIQUE_ID
+            BaseTestCase.TEST_UNIQUE_ID += 1
+
+        # test_regrtest cannot be run twice in parallel because
+        # of setUp() and create_test()
+        name = self.TESTNAME_PREFIX + name
+        path = os.path.join(self.tmptestdir, name + '.py')
+
+        self.addCleanup(support.unlink, path)
+        # Use 'x' mode to ensure that we do not override existing tests
+        try:
+            fd = os.open(path, os.O_WRONLY | os.O_CREAT | os.O_EXCL)
+        except PermissionError as exc:
+            if not sysconfig.is_python_build():
+                self.skipTest("cannot write %s: %s" % (path, exc))
+            raise
+        else:
+            with os.fdopen(fd, 'w') as fp:
+                fp.write(code)
+        return name
+
+    def regex_search(self, regex, output):
+        match = re.search(regex, output, re.MULTILINE)
+        if not match:
+            self.fail("%r not found in %r" % (regex, output))
+        return match
+
+    def check_line(self, output, regex):
+        regex = re.compile(r'^' + regex, re.MULTILINE)
+        self.assertRegexpMatches(output, regex)
+
+    def parse_executed_tests(self, output):
+        regex = (r'^\[ *[0-9]+(?:/ *[0-9]+)*\] (%s)'
+                 % self.TESTNAME_REGEX)
+        parser = re.finditer(regex, output, re.MULTILINE)
+        return list(match.group(1) for match in parser)
+
+    def check_executed_tests(self, output, tests, skipped=(), failed=(),
+                             omitted=(), randomize=False, interrupted=False):
+        if isinstance(tests, str):
+            tests = [tests]
+        if isinstance(skipped, str):
+            skipped = [skipped]
+        if isinstance(failed, str):
+            failed = [failed]
+        if isinstance(omitted, str):
+            omitted = [omitted]
+        ntest = len(tests)
+        nskipped = len(skipped)
+        nfailed = len(failed)
+        nomitted = len(omitted)
+
+        executed = self.parse_executed_tests(output)
+        if randomize:
+            self.assertEqual(set(executed), set(tests), output)
+        else:
+            self.assertEqual(executed, tests, (executed, tests, output))
+
+        def plural(count):
+            return 's' if count != 1 else ''
+
+        def list_regex(line_format, tests):
+            count = len(tests)
+            names = ' '.join(sorted(tests))
+            regex = line_format % (count, plural(count))
+            regex = r'%s:\n    %s$' % (regex, names)
+            return regex
+
+        if skipped:
+            regex = list_regex('%s test%s skipped', skipped)
+            self.check_line(output, regex)
+
+        if failed:
+            regex = list_regex('%s test%s failed', failed)
+            self.check_line(output, regex)
+
+        if omitted:
+            regex = list_regex('%s test%s omitted', omitted)
+            self.check_line(output, regex)
+
+        good = ntest - nskipped - nfailed - nomitted
+        if good:
+            regex = r'%s test%s OK\.$' % (good, plural(good))
+            if not skipped and not failed and good > 1:
+                regex = 'All %s' % regex
+            self.check_line(output, regex)
+
+        if interrupted:
+            self.check_line(output, 'Test suite interrupted by signal SIGINT.')
+
+    def parse_random_seed(self, output):
+        match = self.regex_search(r'Using random seed ([0-9]+)', output)
+        randseed = int(match.group(1))
+        self.assertTrue(0 <= randseed <= 10000000, randseed)
+        return randseed
+
+    def run_command(self, args, input=None, exitcode=0, **kw):
+        if not input:
+            input = ''
+        if 'stderr' not in kw:
+            kw['stderr'] = subprocess.PIPE
+        proc = subprocess.Popen(args,
+                                universal_newlines=True,
+                                stdout=subprocess.PIPE,
+                                **kw)
+        stdout, stderr = proc.communicate(input=input)
+        if proc.returncode != exitcode:
+            msg = ("Command %s failed with exit code %s\n"
+                   "\n"
+                   "stdout:\n"
+                   "---\n"
+                   "%s\n"
+                   "---\n"
+                   % (str(args), proc.returncode, stdout))
+            if proc.stderr:
+                msg += ("\n"
+                        "stderr:\n"
+                        "---\n"
+                        "%s"
+                        "---\n"
+                        % stderr)
+            self.fail(msg)
+        return SubprocssRun(proc.returncode, stdout, stderr)
+
+    def run_python(self, args, **kw):
+        args = [sys.executable] + list(args)
+        proc = self.run_command(args, **kw)
+        return proc.stdout
+
+
+class ProgramsTestCase(BaseTestCase):
+    """
+    Test various ways to run the Python test suite. Use options close
+    to options used on the buildbot.
+    """
+
+    NTEST = 4
+
+    def setUp(self):
+        super(ProgramsTestCase, self).setUp()
+
+        # Create NTEST tests doing nothing
+        self.tests = [self.create_test() for index in range(self.NTEST)]
+
+        self.python_args = ['-Wd', '-E', '-bb']
+        self.regrtest_args = ['-uall', '-rwW',
+                              '--testdir=%s' % self.tmptestdir]
+
+    def check_output(self, output):
+        self.parse_random_seed(output)
+        self.check_executed_tests(output, self.tests, randomize=True)
+
+    def run_tests(self, args):
+        output = self.run_python(args)
+        self.check_output(output)
+
+    def test_script_regrtest(self):
+        # Lib/test/regrtest.py
+        script = os.path.join(self.testdir, 'regrtest.py')
+
+        args = self.python_args + [script] + self.regrtest_args + self.tests
+        self.run_tests(args)
+
+    def test_module_test(self):
+        # -m test
+        args = self.python_args + ['-m', 'test'] + self.regrtest_args + self.tests
+        self.run_tests(args)
+
+    def test_module_regrtest(self):
+        # -m test.regrtest
+        args = self.python_args + ['-m', 'test.regrtest'] + self.regrtest_args + self.tests
+        self.run_tests(args)
+
+    def test_module_autotest(self):
+        # -m test.autotest
+        args = self.python_args + ['-m', 'test.autotest'] + self.regrtest_args + self.tests
+        self.run_tests(args)
+
+    def test_module_from_test_autotest(self):
+        # from test import autotest
+        code = 'from test import autotest'
+        args = self.python_args + ['-c', code] + self.regrtest_args + self.tests
+        self.run_tests(args)
+
+    def test_script_autotest(self):
+        # Lib/test/autotest.py
+        script = os.path.join(self.testdir, 'autotest.py')
+        args = self.python_args + [script] + self.regrtest_args + self.tests
+        self.run_tests(args)
+
+    def run_batch(self, *args):
+        proc = self.run_command(args)
+        self.check_output(proc.stdout)
+
+    @unittest.skipUnless(sysconfig.is_python_build(),
+                         'test.bat script is not installed')
+    @unittest.skipUnless(sys.platform == 'win32', 'Windows only')
+    def test_tools_buildbot_test(self):
+        # Tools\buildbot\test.bat
+        script = os.path.join(ROOT_DIR, 'Tools', 'buildbot', 'test.bat')
+        test_args = ['--testdir=%s' % self.tmptestdir]
+        if platform.architecture()[0] == '64bit':
+            test_args.append('-x64')   # 64-bit build
+        if not Py_DEBUG:
+            test_args.append('+d')     # Release build, use python.exe
+
+        args = [script] + test_args + self.tests
+        self.run_batch(*args)
+
+    @unittest.skipUnless(sys.platform == 'win32', 'Windows only')
+    def test_pcbuild_rt(self):
+        # PCbuild\rt.bat
+        script = os.path.join(ROOT_DIR, r'PCbuild\rt.bat')
+        rt_args = ["-q"]             # Quick, don't run tests twice
+        if platform.architecture()[0] == '64bit':
+            rt_args.append('-x64')   # 64-bit build
+        if Py_DEBUG:
+            rt_args.append('-d')     # Debug build, use python_d.exe
+        args = [script] + rt_args + self.regrtest_args + self.tests
+        self.run_batch(*args)
+
+
+class ArgsTestCase(BaseTestCase):
+    """
+    Test arguments of the Python test suite.
+    """
+
+    def run_tests(self, *testargs, **kw):
+        cmdargs = ('-m', 'test', '--testdir=%s' % self.tmptestdir) + testargs
+        return self.run_python(cmdargs, **kw)
+
+    def test_failing_test(self):
+        # test a failing test
+        code = textwrap.dedent("""
+            import unittest
+            from test import support
+
+            class FailingTest(unittest.TestCase):
+                def test_failing(self):
+                    self.fail("bug")
+
+            def test_main():
+                support.run_unittest(FailingTest)
+        """)
+        test_ok = self.create_test('ok')
+        test_failing = self.create_test('failing', code=code)
+        tests = [test_ok, test_failing]
+
+        output = self.run_tests(*tests, exitcode=1)
+        self.check_executed_tests(output, tests, failed=test_failing)
+
+    def test_resources(self):
+        # test -u command line option
+        tests = {}
+        for resource in ('audio', 'network'):
+            code = 'from test import support\nsupport.requires(%r)' % resource
+            tests[resource] = self.create_test(resource, code)
+        test_names = sorted(tests.values())
+
+        # -u all: 2 resources enabled
+        output = self.run_tests('-u', 'all', *test_names)
+        self.check_executed_tests(output, test_names)
+
+        # -u audio: 1 resource enabled
+        output = self.run_tests('-uaudio', *test_names)
+        self.check_executed_tests(output, test_names,
+                                  skipped=tests['network'])
+
+        # no option: 0 resources enabled
+        output = self.run_tests(*test_names)
+        self.check_executed_tests(output, test_names,
+                                  skipped=test_names)
+
+    def test_random(self):
+        # test -r and --randseed command line option
+        code = textwrap.dedent("""
+            import random
+            print("TESTRANDOM: %s" % random.randint(1, 1000))
+        """)
+        test = self.create_test('random', code)
+
+        # first run to get the output with the random seed
+        output = self.run_tests('-r', '-v', test)
+        randseed = self.parse_random_seed(output)
+        match = self.regex_search(r'TESTRANDOM: ([0-9]+)', output)
+        test_random = int(match.group(1))
+
+        # try to reproduce with the random seed
+        output = self.run_tests('-r', '-v', '--randseed=%s' % randseed, test)
+        randseed2 = self.parse_random_seed(output)
+        self.assertEqual(randseed2, randseed)
+
+        match = self.regex_search(r'TESTRANDOM: ([0-9]+)', output)
+        test_random2 = int(match.group(1))
+        self.assertEqual(test_random2, test_random)
+
+    def test_fromfile(self):
+        # test --fromfile
+        tests = [self.create_test() for index in range(5)]
+
+        # Write the list of files using a format similar to regrtest output:
+        # [1/2] test_1
+        # [2/2] test_2
+        filename = support.TESTFN
+        self.addCleanup(support.unlink, filename)
+
+        # test format 'test_opcodes'
+        with open(filename, "w") as fp:
+            for name in tests:
+                print(name, file=fp)
+
+        output = self.run_tests('--fromfile', filename)
+        self.check_executed_tests(output, tests)
+
+    def test_interrupted(self):
+        code = TEST_INTERRUPTED
+        test = self.create_test('sigint', code=code)
+        output = self.run_tests(test, exitcode=1)
+        self.check_executed_tests(output, test, omitted=test,
+                                  interrupted=True)
+
+    def test_slow(self):
+        # test --slow
+        tests = [self.create_test() for index in range(3)]
+        output = self.run_tests("--slow", *tests)
+        self.check_executed_tests(output, tests)
+        regex = ('10 slowest tests:\n'
+                 '(?:%s: .*\n){%s}'
+                 % (self.TESTNAME_REGEX, len(tests)))
+        self.check_line(output, regex)
+
+    def test_forever(self):
+        # test --forever
+        code = textwrap.dedent("""
+            import __builtin__
+            import unittest
+            from test import support
+
+            class ForeverTester(unittest.TestCase):
+                def test_run(self):
+                    # Store the state in the __builtin__ module, because the test
+                    # module is reload at each run
+                    if 'RUN' in __builtin__.__dict__:
+                        __builtin__.__dict__['RUN'] += 1
+                        if __builtin__.__dict__['RUN'] >= 3:
+                            self.fail("fail at the 3rd runs")
+                    else:
+                        __builtin__.__dict__['RUN'] = 1
+
+            def test_main():
+                support.run_unittest(ForeverTester)
+        """)
+        test = self.create_test('forever', code=code)
+        output = self.run_tests('--forever', test, exitcode=1)
+        self.check_executed_tests(output, [test]*3, failed=test)
+
+    def test_crashed(self):
+        # Any code which causes a crash
+        code = 'import ctypes; ctypes.string_at(0)'
+        crash_test = self.create_test(name="crash", code=code)
+        ok_test = self.create_test(name="ok")
+
+        tests = [crash_test, ok_test]
+        output = self.run_tests("-j2", *tests, exitcode=1)
+        self.check_executed_tests(output, tests, failed=crash_test,
+                                  randomize=True)
+
+
+def test_main():
+    support.run_unittest(ProgramsTestCase, ArgsTestCase)
+
+
+if __name__ == "__main__":
+    test_main()