summaryrefslogtreecommitdiff
path: root/testing/test_faulthandler.py
blob: 370084c125f08f850f7901250bd7e589103524a8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
import io
import sys

import pytest
from _pytest.pytester import Pytester


def test_enabled(pytester: Pytester) -> None:
    """Test single crashing test displays a traceback."""
    pytester.makepyfile(
        """
    import faulthandler
    def test_crash():
        faulthandler._sigabrt()
    """
    )
    result = pytester.runpytest_subprocess()
    result.stderr.fnmatch_lines(["*Fatal Python error*"])
    assert result.ret != 0


def test_crash_near_exit(pytester: Pytester) -> None:
    """Test that fault handler displays crashes that happen even after
    pytest is exiting (for example, when the interpreter is shutting down)."""
    pytester.makepyfile(
        """
    import faulthandler
    import atexit
    def test_ok():
        atexit.register(faulthandler._sigabrt)
    """
    )
    result = pytester.runpytest_subprocess()
    result.stderr.fnmatch_lines(["*Fatal Python error*"])
    assert result.ret != 0


def test_disabled(pytester: Pytester) -> None:
    """Test option to disable fault handler in the command line."""
    pytester.makepyfile(
        """
    import faulthandler
    def test_disabled():
        assert not faulthandler.is_enabled()
    """
    )
    result = pytester.runpytest_subprocess("-p", "no:faulthandler")
    result.stdout.fnmatch_lines(["*1 passed*"])
    assert result.ret == 0


@pytest.mark.parametrize(
    "enabled",
    [
        pytest.param(
            True, marks=pytest.mark.skip(reason="sometimes crashes on CI (#7022)")
        ),
        False,
    ],
)
def test_timeout(pytester: Pytester, enabled: bool) -> None:
    """Test option to dump tracebacks after a certain timeout.

    If faulthandler is disabled, no traceback will be dumped.
    """
    pytester.makepyfile(
        """
    import os, time
    def test_timeout():
        time.sleep(1 if "CI" in os.environ else 0.1)
    """
    )
    pytester.makeini(
        """
        [pytest]
        faulthandler_timeout = 0.01
        """
    )
    args = ["-p", "no:faulthandler"] if not enabled else []

    result = pytester.runpytest_subprocess(*args)
    tb_output = "most recent call first"
    if enabled:
        result.stderr.fnmatch_lines(["*%s*" % tb_output])
    else:
        assert tb_output not in result.stderr.str()
    result.stdout.fnmatch_lines(["*1 passed*"])
    assert result.ret == 0


@pytest.mark.parametrize("hook_name", ["pytest_enter_pdb", "pytest_exception_interact"])
def test_cancel_timeout_on_hook(monkeypatch, hook_name) -> None:
    """Make sure that we are cancelling any scheduled traceback dumping due
    to timeout before entering pdb (pytest-dev/pytest-faulthandler#12) or any
    other interactive exception (pytest-dev/pytest-faulthandler#14)."""
    import faulthandler
    from _pytest.faulthandler import FaultHandlerHooks

    called = []

    monkeypatch.setattr(
        faulthandler, "cancel_dump_traceback_later", lambda: called.append(1)
    )

    # call our hook explicitly, we can trust that pytest will call the hook
    # for us at the appropriate moment
    hook_func = getattr(FaultHandlerHooks, hook_name)
    hook_func(self=None)
    assert called == [1]


@pytest.mark.parametrize("faulthandler_timeout", [0, 2])
def test_already_initialized(faulthandler_timeout: int, pytester: Pytester) -> None:
    """Test for faulthandler being initialized earlier than pytest (#6575)."""
    pytester.makepyfile(
        """
        def test():
            import faulthandler
            assert faulthandler.is_enabled()
    """
    )
    result = pytester.run(
        sys.executable,
        "-X",
        "faulthandler",
        "-mpytest",
        pytester.path,
        "-o",
        f"faulthandler_timeout={faulthandler_timeout}",
    )
    # ensure warning is emitted if faulthandler_timeout is configured
    warning_line = "*faulthandler.py*faulthandler module enabled before*"
    if faulthandler_timeout > 0:
        result.stdout.fnmatch_lines(warning_line)
    else:
        result.stdout.no_fnmatch_line(warning_line)
    result.stdout.fnmatch_lines("*1 passed*")
    assert result.ret == 0


def test_get_stderr_fileno_invalid_fd() -> None:
    """Test for faulthandler being able to handle invalid file descriptors for stderr (#8249)."""
    from _pytest.faulthandler import FaultHandlerHooks

    class StdErrWrapper(io.StringIO):
        """
        Mimic ``twisted.logger.LoggingFile`` to simulate returning an invalid file descriptor.

        https://github.com/twisted/twisted/blob/twisted-20.3.0/src/twisted/logger/_io.py#L132-L139
        """

        def fileno(self):
            return -1

    wrapper = StdErrWrapper()

    with pytest.MonkeyPatch.context() as mp:
        mp.setattr("sys.stderr", wrapper)

        # Even when the stderr wrapper signals an invalid file descriptor,
        # ``_get_stderr_fileno()`` should return the real one.
        assert FaultHandlerHooks._get_stderr_fileno() == 2