[2.7] bpo-30523, bpo-30764, bpo-30776: Sync regrtest from master (#2444)

* bpo-30523: regrtest --list-cases --match (#2401)

* regrtest --list-cases now supports --match and --match-file options.
  Example: ./python -m test --list-cases -m FileTests test_os
* --list-cases now also sets support.verbose to False to prevent
  messages to stdout when loading test modules.
* Add support._match_test() private function.
(cherry picked from commit ace56d5)

(cherry picked from commit 36946c0)

* bpo-30764: regrtest: add --fail-env-changed option (#2402)

* bpo-30764: regrtest: change exit code on failure

* Exit code 2 if failed tests ("bad")
* Exit code 3 if interrupted

* bpo-30764: regrtest: add --fail-env-changed option

If the option is set, mark a test as failed if it alters the
environment, for example if it creates a file without removing it.

(cherry picked from commit 63f54c6)
(cherry picked from commit 1f33857)

* bpo-30776: reduce regrtest -R false positives (#2422)

* Change the regrtest --huntrleaks checker to decide if a test file
  leaks or not. Require that each run leaks at least 1 reference.
* Warmup runs are now completely ignored: ignored in the checker test
  and not used anymore to compute the sum.
* Add an unit test for a reference leak.

Example of reference differences previously considered a failure
(leak) and now considered as success (success, no leak):

    [3, 0, 0]
    [0, 1, 0]
    [8, -8, 1]
(cherry picked from commit 48b5c42)

(cherry picked from commit e0f8b43)

Author: vstinner

Lib/test/regrtest.py

@@ -67,6 +67,8 @@
                    don't execute them
 --list-cases    -- only write the name of test cases that will be run,
                    don't execute them
+--fail-env-changed  -- if a test file alters the environment, mark the test
+                       as failed
 
 
 Additional Option Details:
@@ -327,7 +329,7 @@ def main(tests=None, testdir=None, verbose=0, quiet=False,
              'runleaks', 'huntrleaks=', 'memlimit=', 'randseed=',
              'multiprocess=', 'slaveargs=', 'forever', 'header', 'pgo',
              'failfast', 'match=', 'testdir=', 'list-tests', 'list-cases',
-             'coverage', 'matchfile='])
+             'coverage', 'matchfile=', 'fail-env-changed'])
     except getopt.error, msg:
         usage(2, msg)
 
@@ -339,6 +341,7 @@ def main(tests=None, testdir=None, verbose=0, quiet=False,
     slaveargs = None
     list_tests = False
     list_cases_opt = False
+    fail_env_changed = False
     for o, a in opts:
         if o in ('-h', '--help'):
             usage(0)
@@ -439,6 +442,8 @@ def main(tests=None, testdir=None, verbose=0, quiet=False,
             list_tests = True
         elif o == '--list-cases':
             list_cases_opt = True
+        elif o == '--fail-env-changed':
+            fail_env_changed = True
         else:
             print >>sys.stderr, ("No handler for option {}.  Please "
                 "report this as a bug at http://bugs.python.org.").format(o)
@@ -558,7 +563,7 @@ def main(tests=None, testdir=None, verbose=0, quiet=False,
         sys.exit(0)
 
     if list_cases_opt:
-        list_cases(testdir, selected)
+        list_cases(testdir, selected, match_tests)
         sys.exit(0)
 
     if trace:
@@ -908,11 +913,19 @@ def local_runtest():
         result = "FAILURE"
     elif interrupted:
         result = "INTERRUPTED"
+    elif environment_changed and fail_env_changed:
+        result = "ENV CHANGED"
     else:
         result = "SUCCESS"
     print("Tests result: %s" % result)
 
-    sys.exit(len(bad) > 0 or interrupted)
+    if bad:
+        sys.exit(2)
+    if interrupted:
+        sys.exit(130)
+    if fail_env_changed and environment_changed:
+        sys.exit(3)
+    sys.exit(0)
 
 
 STDTESTS = [
@@ -1310,7 +1323,18 @@ def run_the_test():
         if i >= nwarmup:
             deltas.append(rc_after - rc_before)
     print >> sys.stderr
-    if any(deltas):
+
+    # bpo-30776: Try to ignore false positives:
+    #
+    #   [3, 0, 0]
+    #   [0, 1, 0]
+    #   [8, -8, 1]
+    #
+    # Expected leaks:
+    #
+    #   [5, 5, 6]
+    #   [10, 1, 1]
+    if all(delta >= 1 for delta in deltas):
         msg = '%s leaked %s references, sum=%s' % (test, deltas, sum(deltas))
         print >> sys.stderr, msg
         with open(fname, "a") as refrep:
@@ -1501,9 +1525,13 @@ def _list_cases(suite):
         if isinstance(test, unittest.TestSuite):
             _list_cases(test)
         elif isinstance(test, unittest.TestCase):
-            print(test.id())
+            if test_support._match_test(test):
+                print(test.id())
+
+def list_cases(testdir, selected, match_tests):
+    test_support.verbose = False
+    test_support.match_tests = match_tests
 
-def list_cases(testdir, selected):
     skipped = []
     for test in selected:
         abstest = get_abs_module(testdir, test)

Lib/test/support/__init__.py

@@ -1542,6 +1542,23 @@ def _run_suite(suite):
         raise TestFailed(err)
 
 
+def _match_test(test):
+    global match_tests
+
+    if match_tests is None:
+        return True
+    test_id = test.id()
+
+    for match_test in match_tests:
+        if fnmatch.fnmatchcase(test_id, match_test):
+            return True
+
+        for name in test_id.split("."):
+            if fnmatch.fnmatchcase(name, match_test):
+                return True
+    return False
+
+
 def run_unittest(*classes):
     """Run tests from unittest.TestCase-derived classes."""
     valid_types = (unittest.TestSuite, unittest.TestCase)
@@ -1556,20 +1573,7 @@ def run_unittest(*classes):
             suite.addTest(cls)
         else:
             suite.addTest(unittest.makeSuite(cls))
-    def case_pred(test):
-        if match_tests is None:
-            return True
-        test_id = test.id()
-
-        for match_test in match_tests:
-            if fnmatch.fnmatchcase(test_id, match_test):
-                return True
-
-            for name in test_id.split("."):
-                if fnmatch.fnmatchcase(name, match_test):
-                    return True
-        return False
-    _filter_suite(suite, case_pred)
+    _filter_suite(suite, _match_test)
     _run_suite(suite)
 
 #=======================================================================

Lib/test/test_regrtest.py

@@ -91,19 +91,19 @@ def parse_executed_tests(self, output):
         return list(match.group(1) for match in parser)
 
     def check_executed_tests(self, output, tests, skipped=(), failed=(),
-                             omitted=(), randomize=False, interrupted=False):
+                             env_changed=(), omitted=(),
+                             randomize=False, interrupted=False,
+                             fail_env_changed=False):
         if isinstance(tests, str):
             tests = [tests]
         if isinstance(skipped, str):
             skipped = [skipped]
         if isinstance(failed, str):
             failed = [failed]
+        if isinstance(env_changed, str):
+            env_changed = [env_changed]
         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:
@@ -129,11 +129,17 @@ def list_regex(line_format, tests):
             regex = list_regex('%s test%s failed', failed)
             self.check_line(output, regex)
 
+        if env_changed:
+            regex = list_regex('%s test%s altered the execution environment',
+                               env_changed)
+            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
+        good = (len(tests) - len(skipped) - len(failed)
+                - len(omitted) - len(env_changed))
         if good:
             regex = r'%s test%s OK\.$' % (good, plural(good))
             if not skipped and not failed and good > 1:
@@ -143,10 +149,12 @@ def list_regex(line_format, tests):
         if interrupted:
             self.check_line(output, 'Test suite interrupted by signal SIGINT.')
 
-        if nfailed:
+        if failed:
             result = 'FAILURE'
         elif interrupted:
             result = 'INTERRUPTED'
+        elif fail_env_changed and env_changed:
+            result = 'ENV CHANGED'
         else:
             result = 'SUCCESS'
         self.check_line(output, 'Tests result: %s' % result)
@@ -325,7 +333,7 @@ def test_main():
         test_failing = self.create_test('failing', code=code)
         tests = [test_ok, test_failing]
 
-        output = self.run_tests(*tests, exitcode=1)
+        output = self.run_tests(*tests, exitcode=2)
         self.check_executed_tests(output, tests, failed=test_failing)
 
     def test_resources(self):
@@ -394,7 +402,7 @@ def test_fromfile(self):
     def test_interrupted(self):
         code = TEST_INTERRUPTED
         test = self.create_test('sigint', code=code)
-        output = self.run_tests(test, exitcode=1)
+        output = self.run_tests(test, exitcode=130)
         self.check_executed_tests(output, test, omitted=test,
                                   interrupted=True)
 
@@ -423,7 +431,7 @@ def test_slow_interrupted(self):
                 args = ("--slowest", "-j2", test)
             else:
                 args = ("--slowest", test)
-            output = self.run_tests(*args, exitcode=1)
+            output = self.run_tests(*args, exitcode=130)
             self.check_executed_tests(output, test,
                                       omitted=test, interrupted=True)
 
@@ -461,24 +469,88 @@ def test_main():
                 support.run_unittest(ForeverTester)
         """)
         test = self.create_test('forever', code=code)
-        output = self.run_tests('--forever', test, exitcode=1)
+        output = self.run_tests('--forever', test, exitcode=2)
         self.check_executed_tests(output, [test]*3, failed=test)
 
+    def check_leak(self, code, what):
+        test = self.create_test('huntrleaks', code=code)
+
+        filename = 'reflog.txt'
+        self.addCleanup(support.unlink, filename)
+        output = self.run_tests('--huntrleaks', '3:3:', test,
+                                exitcode=2,
+                                stderr=subprocess.STDOUT)
+        self.check_executed_tests(output, [test], failed=test)
+
+        line = 'beginning 6 repetitions\n123456\n......\n'
+        self.check_line(output, re.escape(line))
+
+        line2 = '%s leaked [1, 1, 1] %s, sum=3\n' % (test, what)
+        self.assertIn(line2, output)
+
+        with open(filename) as fp:
+            reflog = fp.read()
+            self.assertIn(line2, reflog)
+
+    @unittest.skipUnless(Py_DEBUG, 'need a debug build')
+    def test_huntrleaks(self):
+        # test --huntrleaks
+        code = textwrap.dedent("""
+            import unittest
+            from test import support
+
+            GLOBAL_LIST = []
+
+            class RefLeakTest(unittest.TestCase):
+                def test_leak(self):
+                    GLOBAL_LIST.append(object())
+
+            def test_main():
+                support.run_unittest(RefLeakTest)
+        """)
+        self.check_leak(code, 'references')
+
     def test_list_tests(self):
         # test --list-tests
         tests = [self.create_test() for i in range(5)]
         output = self.run_tests('--list-tests', *tests)
         self.assertEqual(output.rstrip().splitlines(),
                          tests)
 
+    def test_list_cases(self):
+        # test --list-cases
+        code = textwrap.dedent("""
+            import unittest
+
+            class Tests(unittest.TestCase):
+                def test_method1(self):
+                    pass
+                def test_method2(self):
+                    pass
+        """)
+        testname = self.create_test(code=code)
+
+        # Test --list-cases
+        all_methods = ['%s.Tests.test_method1' % testname,
+                       '%s.Tests.test_method2' % testname]
+        output = self.run_tests('--list-cases', testname)
+        self.assertEqual(output.splitlines(), all_methods)
+
+        # Test --list-cases with --match
+        all_methods = ['%s.Tests.test_method1' % testname]
+        output = self.run_tests('--list-cases',
+                                '-m', 'test_method1',
+                                testname)
+        self.assertEqual(output.splitlines(), all_methods)
+
     def test_crashed(self):
         # Any code which causes a crash
         code = 'import test.support; test.support._crash_python()'
         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)
+        output = self.run_tests("-j2", *tests, exitcode=2)
         self.check_executed_tests(output, tests, failed=crash_test,
                                   randomize=True)
 
@@ -532,26 +604,28 @@ def test_main():
         subset = ['test_method1', 'test_method3']
         self.assertEqual(methods, subset)
 
-    def test_list_cases(self):
-        # test --list-cases
+    def test_env_changed(self):
         code = textwrap.dedent("""
             import unittest
             from test import support
 
             class Tests(unittest.TestCase):
-                def test_method1(self):
-                    pass
-                def test_method2(self):
-                    pass
+                def test_env_changed(self):
+                    open("env_changed", "w").close()
 
             def test_main():
                 support.run_unittest(Tests)
         """)
         testname = self.create_test(code=code)
-        all_methods = ['%s.Tests.test_method1' % testname,
-                       '%s.Tests.test_method2' % testname]
-        output = self.run_tests('--list-cases', testname)
-        self.assertEqual(output.splitlines(), all_methods)
+
+        # don't fail by default
+        output = self.run_tests(testname)
+        self.check_executed_tests(output, [testname], env_changed=testname)
+
+        # fail with --fail-env-changed
+        output = self.run_tests("--fail-env-changed", testname, exitcode=3)
+        self.check_executed_tests(output, [testname], env_changed=testname,
+                                  fail_env_changed=True)
 
 
 def test_main():