Add coverage

tools/telemetry/third_party/coverage/tests/test_oddball.py

+# Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0
+# For details: https://bitbucket.org/ned/coveragepy/src/default/NOTICE.txt
+
+"""Oddball cases for testing coverage.py"""
+
+import sys
+
+import coverage
+from coverage.files import abs_file
+
+from tests.coveragetest import CoverageTest
+from tests import osinfo
+
+
+class ThreadingTest(CoverageTest):
+    """Tests of the threading support."""
+
+    def test_threading(self):
+        self.check_coverage("""\
+            import threading
+
+            def fromMainThread():
+                return "called from main thread"
+
+            def fromOtherThread():
+                return "called from other thread"
+
+            def neverCalled():
+                return "no one calls me"
+
+            other = threading.Thread(target=fromOtherThread)
+            other.start()
+            fromMainThread()
+            other.join()
+            """,
+            [1, 3, 4, 6, 7, 9, 10, 12, 13, 14, 15], "10")
+
+    def test_thread_run(self):
+        self.check_coverage("""\
+            import threading
+
+            class TestThread(threading.Thread):
+                def run(self):
+                    self.a = 5
+                    self.do_work()
+                    self.a = 7
+
+                def do_work(self):
+                    self.a = 10
+
+            thd = TestThread()
+            thd.start()
+            thd.join()
+            """,
+            [1, 3, 4, 5, 6, 7, 9, 10, 12, 13, 14], "")
+
+
+class RecursionTest(CoverageTest):
+    """Check what happens when recursive code gets near limits."""
+
+    def test_short_recursion(self):
+        # We can definitely get close to 500 stack frames.
+        self.check_coverage("""\
+            def recur(n):
+                if n == 0:
+                    return 0
+                else:
+                    return recur(n-1)+1
+
+            recur(495)  # We can get at least this many stack frames.
+            i = 8       # and this line will be traced
+            """,
+            [1, 2, 3, 5, 7, 8], "")
+
+    def test_long_recursion(self):
+        # We can't finish a very deep recursion, but we don't crash.
+        with self.assertRaises(RuntimeError):
+            self.check_coverage("""\
+                def recur(n):
+                    if n == 0:
+                        return 0
+                    else:
+                        return recur(n-1)+1
+
+                recur(100000)  # This is definitely too many frames.
+                """,
+                [1, 2, 3, 5, 7], ""
+                )
+
+    def test_long_recursion_recovery(self):
+        # Test the core of bug 93: http://bitbucket.org/ned/coveragepy/issue/93
+        # When recovering from a stack overflow, the Python trace function is
+        # disabled, but the C trace function is not.  So if we're using a
+        # Python trace function, we won't trace anything after the stack
+        # overflow, and there should be a warning about it.  If we're using
+        # the C trace function, only line 3 will be missing, and all else
+        # will be traced.
+
+        self.make_file("recur.py", """\
+            def recur(n):
+                if n == 0:
+                    return 0    # never hit
+                else:
+                    return recur(n-1)+1
+
+            try:
+                recur(100000)  # This is definitely too many frames.
+            except RuntimeError:
+                i = 10
+            i = 11
+            """)
+
+        cov = coverage.Coverage()
+        self.start_import_stop(cov, "recur")
+
+        pytrace = (cov.collector.tracer_name() == "PyTracer")
+        expected_missing = [3]
+        if pytrace:
+            expected_missing += [9, 10, 11]
+
+        _, statements, missing, _ = cov.analysis("recur.py")
+        self.assertEqual(statements, [1, 2, 3, 5, 7, 8, 9, 10, 11])
+        self.assertEqual(missing, expected_missing)
+
+        # Get a warning about the stackoverflow effect on the tracing function.
+        if pytrace:
+            self.assertEqual(cov._warnings,
+                ["Trace function changed, measurement is likely wrong: None"]
+                )
+        else:
+            self.assertEqual(cov._warnings, [])
+
+
+class MemoryLeakTest(CoverageTest):
+    """Attempt the impossible: test that memory doesn't leak.
+
+    Note: this test is truly unusual, and has had a colorful history.  See
+    for example: https://bitbucket.org/ned/coveragepy/issue/186
+
+    It may still fail occasionally, especially on PyPy.
+
+    """
+    def test_for_leaks(self):
+        # Our original bad memory leak only happened on line numbers > 255, so
+        # make a code object with more lines than that.  Ugly string mumbo
+        # jumbo to get 300 blank lines at the beginning..
+        code = """\
+            # blank line\n""" * 300 + """\
+            def once(x):                                        # line 301
+                if x % 100 == 0:
+                    raise Exception("100!")
+                elif x % 2:
+                    return 10
+                else:                                           # line 306
+                    return 11
+            i = 0 # Portable loop without alloc'ing memory.
+            while i < ITERS:
+                try:
+                    once(i)
+                except:
+                    pass
+                i += 1                                          # line 315
+            """
+        lines = list(range(301, 315))
+        lines.remove(306)       # Line 306 is the "else".
+
+        # This is a non-deterministic test, so try it a few times, and fail it
+        # only if it predominantly fails.
+        fails = 0
+        for _ in range(10):
+            ram_0 = osinfo.process_ram()
+            self.check_coverage(code.replace("ITERS", "10"), lines, "")
+            ram_10 = osinfo.process_ram()
+            self.check_coverage(code.replace("ITERS", "10000"), lines, "")
+            ram_10k = osinfo.process_ram()
+            # Running the code 10k times shouldn't grow the ram much more than
+            # running it 10 times.
+            ram_growth = (ram_10k - ram_10) - (ram_10 - ram_0)
+            if ram_growth > 100000:                     # pragma: only failure
+                fails += 1
+
+        if fails > 8:                                   # pragma: only failure
+            self.fail("RAM grew by %d" % (ram_growth))
+
+
+class PyexpatTest(CoverageTest):
+    """Pyexpat screws up tracing. Make sure we've counter-defended properly."""
+
+    def test_pyexpat(self):
+        # pyexpat calls the trace function explicitly (inexplicably), and does
+        # it wrong for exceptions.  Parsing a DOCTYPE for some reason throws
+        # an exception internally, and triggers its wrong behavior.  This test
+        # checks that our fake PyTrace_RETURN hack in tracer.c works.  It will
+        # also detect if the pyexpat bug is fixed unbeknownst to us, meaning
+        # we'd see two RETURNs where there should only be one.
+
+        self.make_file("trydom.py", """\
+            import xml.dom.minidom
+
+            XML = '''\\
+            <!DOCTYPE fooey SYSTEM "http://www.example.com/example.dtd">
+            <root><child/><child/></root>
+            '''
+
+            def foo():
+                dom = xml.dom.minidom.parseString(XML)
+                assert len(dom.getElementsByTagName('child')) == 2
+                a = 11
+
+            foo()
+            """)
+
+        self.make_file("outer.py", "\n"*100 + "import trydom\na = 102\n")
+
+        cov = coverage.Coverage()
+        cov.erase()
+
+        # Import the Python file, executing it.
+        self.start_import_stop(cov, "outer")
+
+        _, statements, missing, _ = cov.analysis("trydom.py")
+        self.assertEqual(statements, [1, 3, 8, 9, 10, 11, 13])
+        self.assertEqual(missing, [])
+
+        _, statements, missing, _ = cov.analysis("outer.py")
+        self.assertEqual(statements, [101, 102])
+        self.assertEqual(missing, [])
+
+
+class ExceptionTest(CoverageTest):
+    """I suspect different versions of Python deal with exceptions differently
+    in the trace function.
+    """
+
+    def test_exception(self):
+        # Python 2.3's trace function doesn't get called with "return" if the
+        # scope is exiting due to an exception.  This confounds our trace
+        # function which relies on scope announcements to track which files to
+        # trace.
+        #
+        # This test is designed to sniff this out.  Each function in the call
+        # stack is in a different file, to try to trip up the tracer.  Each
+        # file has active lines in a different range so we'll see if the lines
+        # get attributed to the wrong file.
+
+        self.make_file("oops.py", """\
+            def oops(args):
+                a = 2
+                raise Exception("oops")
+                a = 4
+            """)
+
+        self.make_file("fly.py", "\n"*100 + """\
+            def fly(calls):
+                a = 2
+                calls[0](calls[1:])
+                a = 4
+            """)
+
+        self.make_file("catch.py", "\n"*200 + """\
+            def catch(calls):
+                try:
+                    a = 3
+                    calls[0](calls[1:])
+                    a = 5
+                except:
+                    a = 7
+            """)
+
+        self.make_file("doit.py", "\n"*300 + """\
+            def doit(calls):
+                try:
+                    calls[0](calls[1:])
+                except:
+                    a = 5
+            """)
+
+        # Import all the modules before starting coverage, so the def lines
+        # won't be in all the results.
+        for mod in "oops fly catch doit".split():
+            self.import_local_file(mod)
+
+        # Each run nests the functions differently to get different
+        # combinations of catching exceptions and letting them fly.
+        runs = [
+            ("doit fly oops", {
+                'doit.py': [302, 303, 304, 305],
+                'fly.py': [102, 103],
+                'oops.py': [2, 3],
+                }),
+            ("doit catch oops", {
+                'doit.py': [302, 303],
+                'catch.py': [202, 203, 204, 206, 207],
+                'oops.py': [2, 3],
+                }),
+            ("doit fly catch oops", {
+                'doit.py': [302, 303],
+                'fly.py': [102, 103, 104],
+                'catch.py': [202, 203, 204, 206, 207],
+                'oops.py': [2, 3],
+                }),
+            ("doit catch fly oops", {
+                'doit.py': [302, 303],
+                'catch.py': [202, 203, 204, 206, 207],
+                'fly.py': [102, 103],
+                'oops.py': [2, 3],
+                }),
+            ]
+
+        for callnames, lines_expected in runs:
+
+            # Make the list of functions we'll call for this test.
+            callnames = callnames.split()
+            calls = [getattr(sys.modules[cn], cn) for cn in callnames]
+
+            cov = coverage.Coverage()
+            cov.start()
+            # Call our list of functions: invoke the first, with the rest as
+            # an argument.
+            calls[0](calls[1:])     # pragma: nested
+            cov.stop()              # pragma: nested
+
+            # Clean the line data and compare to expected results.
+            # The file names are absolute, so keep just the base.
+            clean_lines = {}
+            data = cov.get_data()
+            for callname in callnames:
+                filename = callname + ".py"
+                lines = data.lines(abs_file(filename))
+                clean_lines[filename] = sorted(lines)
+
+            self.assertEqual(clean_lines, lines_expected)
+
+
+class DoctestTest(CoverageTest):
+    """Tests invoked with doctest should measure properly."""
+
+    def setUp(self):
+        super(DoctestTest, self).setUp()
+
+        # Oh, the irony!  This test case exists because Python 2.4's
+        # doctest module doesn't play well with coverage.  But nose fixes
+        # the problem by monkeypatching doctest.  I want to undo the
+        # monkeypatch to be sure I'm getting the doctest module that users
+        # of coverage will get.  Deleting the imported module here is
+        # enough: when the test imports doctest again, it will get a fresh
+        # copy without the monkeypatch.
+        del sys.modules['doctest']
+
+    def test_doctest(self):
+        self.check_coverage('''\
+            def return_arg_or_void(arg):
+                """If <arg> is None, return "Void"; otherwise return <arg>
+
+                >>> return_arg_or_void(None)
+                'Void'
+                >>> return_arg_or_void("arg")
+                'arg'
+                >>> return_arg_or_void("None")
+                'None'
+                """
+                if arg is None:
+                    return "Void"
+                else:
+                    return arg
+
+            import doctest, sys
+            doctest.testmod(sys.modules[__name__])  # we're not __main__ :(
+            ''',
+            [1, 11, 12, 14, 16, 17], "")
+
+
+class GettraceTest(CoverageTest):
+    """Tests that we work properly with `sys.gettrace()`."""
+    def test_round_trip(self):
+        self.check_coverage('''\
+            import sys
+            def foo(n):
+                return 3*n
+            def bar(n):
+                return 5*n
+            a = foo(6)
+            sys.settrace(sys.gettrace())
+            a = bar(8)
+            ''',
+            [1, 2, 3, 4, 5, 6, 7, 8], "")
+
+    def test_multi_layers(self):
+        self.check_coverage('''\
+            import sys
+            def level1():
+                a = 3
+                level2()
+                b = 5
+            def level2():
+                c = 7
+                sys.settrace(sys.gettrace())
+                d = 9
+            e = 10
+            level1()
+            f = 12
+            ''',
+            [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12], "")
+
+
+class ExecTest(CoverageTest):
+    """Tests of exec."""
+    def test_correct_filename(self):
+        # https://bitbucket.org/ned/coveragepy/issues/380/code-executed-by-exec-excluded-from
+        # Bug was that exec'd files would have their lines attributed to the
+        # calling file.  Make two files, both with ~30 lines, but no lines in
+        # common.  Line 30 in to_exec.py was recorded as line 30 in main.py,
+        # but now it's fixed. :)
+        self.make_file("to_exec.py", """\
+            \n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
+            print("var is {0}".format(var))         # line 31
+            """)
+        self.make_file("main.py", """\
+            namespace = {'var': 17}
+            with open("to_exec.py") as to_exec_py:
+                code = compile(to_exec_py.read(), 'to_exec.py', 'exec')
+                exec(code, globals(), namespace)
+            \n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
+            print("done")                           # line 35
+            """)
+
+        cov = coverage.Coverage()
+        self.start_import_stop(cov, "main")
+
+        _, statements, missing, _ = cov.analysis("main.py")
+        self.assertEqual(statements, [1, 2, 3, 4, 35])
+        self.assertEqual(missing, [])
+        _, statements, missing, _ = cov.analysis("to_exec.py")
+        self.assertEqual(statements, [31])
+        self.assertEqual(missing, [])