621 lines
20 KiB
Python
621 lines
20 KiB
Python
"""
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per-test stdout/stderr capturing mechanism.
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"""
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from __future__ import absolute_import, division, print_function
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import contextlib
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import sys
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import os
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import io
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from io import UnsupportedOperation
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from tempfile import TemporaryFile
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import six
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import pytest
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from _pytest.compat import CaptureIO
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patchsysdict = {0: 'stdin', 1: 'stdout', 2: 'stderr'}
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def pytest_addoption(parser):
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group = parser.getgroup("general")
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group._addoption(
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'--capture', action="store",
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default="fd" if hasattr(os, "dup") else "sys",
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metavar="method", choices=['fd', 'sys', 'no'],
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help="per-test capturing method: one of fd|sys|no.")
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group._addoption(
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'-s', action="store_const", const="no", dest="capture",
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help="shortcut for --capture=no.")
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@pytest.hookimpl(hookwrapper=True)
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def pytest_load_initial_conftests(early_config, parser, args):
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ns = early_config.known_args_namespace
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if ns.capture == "fd":
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_py36_windowsconsoleio_workaround(sys.stdout)
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_colorama_workaround()
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_readline_workaround()
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pluginmanager = early_config.pluginmanager
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capman = CaptureManager(ns.capture)
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pluginmanager.register(capman, "capturemanager")
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# make sure that capturemanager is properly reset at final shutdown
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early_config.add_cleanup(capman.stop_global_capturing)
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# make sure logging does not raise exceptions at the end
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def silence_logging_at_shutdown():
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if "logging" in sys.modules:
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sys.modules["logging"].raiseExceptions = False
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early_config.add_cleanup(silence_logging_at_shutdown)
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# finally trigger conftest loading but while capturing (issue93)
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capman.start_global_capturing()
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outcome = yield
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out, err = capman.suspend_global_capture()
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if outcome.excinfo is not None:
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sys.stdout.write(out)
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sys.stderr.write(err)
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class CaptureManager:
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"""
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Capture plugin, manages that the appropriate capture method is enabled/disabled during collection and each
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test phase (setup, call, teardown). After each of those points, the captured output is obtained and
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attached to the collection/runtest report.
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There are two levels of capture:
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* global: which is enabled by default and can be suppressed by the ``-s`` option. This is always enabled/disabled
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during collection and each test phase.
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* fixture: when a test function or one of its fixture depend on the ``capsys`` or ``capfd`` fixtures. In this
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case special handling is needed to ensure the fixtures take precedence over the global capture.
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"""
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def __init__(self, method):
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self._method = method
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self._global_capturing = None
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def _getcapture(self, method):
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if method == "fd":
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return MultiCapture(out=True, err=True, Capture=FDCapture)
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elif method == "sys":
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return MultiCapture(out=True, err=True, Capture=SysCapture)
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elif method == "no":
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return MultiCapture(out=False, err=False, in_=False)
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else:
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raise ValueError("unknown capturing method: %r" % method)
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def start_global_capturing(self):
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assert self._global_capturing is None
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self._global_capturing = self._getcapture(self._method)
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self._global_capturing.start_capturing()
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def stop_global_capturing(self):
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if self._global_capturing is not None:
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self._global_capturing.pop_outerr_to_orig()
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self._global_capturing.stop_capturing()
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self._global_capturing = None
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def resume_global_capture(self):
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self._global_capturing.resume_capturing()
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def suspend_global_capture(self, item=None, in_=False):
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if item is not None:
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self.deactivate_fixture(item)
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cap = getattr(self, "_global_capturing", None)
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if cap is not None:
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try:
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outerr = cap.readouterr()
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finally:
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cap.suspend_capturing(in_=in_)
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return outerr
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def activate_fixture(self, item):
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"""If the current item is using ``capsys`` or ``capfd``, activate them so they take precedence over
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the global capture.
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"""
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fixture = getattr(item, "_capture_fixture", None)
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if fixture is not None:
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fixture._start()
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def deactivate_fixture(self, item):
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"""Deactivates the ``capsys`` or ``capfd`` fixture of this item, if any."""
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fixture = getattr(item, "_capture_fixture", None)
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if fixture is not None:
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fixture.close()
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@pytest.hookimpl(hookwrapper=True)
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def pytest_make_collect_report(self, collector):
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if isinstance(collector, pytest.File):
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self.resume_global_capture()
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outcome = yield
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out, err = self.suspend_global_capture()
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rep = outcome.get_result()
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if out:
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rep.sections.append(("Captured stdout", out))
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if err:
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rep.sections.append(("Captured stderr", err))
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else:
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yield
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@pytest.hookimpl(hookwrapper=True)
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def pytest_runtest_setup(self, item):
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self.resume_global_capture()
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# no need to activate a capture fixture because they activate themselves during creation; this
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# only makes sense when a fixture uses a capture fixture, otherwise the capture fixture will
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# be activated during pytest_runtest_call
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yield
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self.suspend_capture_item(item, "setup")
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@pytest.hookimpl(hookwrapper=True)
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def pytest_runtest_call(self, item):
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self.resume_global_capture()
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# it is important to activate this fixture during the call phase so it overwrites the "global"
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# capture
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self.activate_fixture(item)
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yield
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self.suspend_capture_item(item, "call")
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@pytest.hookimpl(hookwrapper=True)
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def pytest_runtest_teardown(self, item):
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self.resume_global_capture()
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self.activate_fixture(item)
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yield
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self.suspend_capture_item(item, "teardown")
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@pytest.hookimpl(tryfirst=True)
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def pytest_keyboard_interrupt(self, excinfo):
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self.stop_global_capturing()
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@pytest.hookimpl(tryfirst=True)
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def pytest_internalerror(self, excinfo):
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self.stop_global_capturing()
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def suspend_capture_item(self, item, when, in_=False):
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out, err = self.suspend_global_capture(item, in_=in_)
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item.add_report_section(when, "stdout", out)
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item.add_report_section(when, "stderr", err)
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error_capsysfderror = "cannot use capsys and capfd at the same time"
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@pytest.fixture
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def capsys(request):
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"""Enable capturing of writes to sys.stdout/sys.stderr and make
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captured output available via ``capsys.readouterr()`` method calls
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which return a ``(out, err)`` tuple.
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"""
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if "capfd" in request.fixturenames:
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raise request.raiseerror(error_capsysfderror)
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with _install_capture_fixture_on_item(request, SysCapture) as fixture:
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yield fixture
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@pytest.fixture
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def capfd(request):
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"""Enable capturing of writes to file descriptors 1 and 2 and make
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captured output available via ``capfd.readouterr()`` method calls
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which return a ``(out, err)`` tuple.
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"""
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if "capsys" in request.fixturenames:
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request.raiseerror(error_capsysfderror)
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if not hasattr(os, 'dup'):
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pytest.skip("capfd fixture needs os.dup function which is not available in this system")
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with _install_capture_fixture_on_item(request, FDCapture) as fixture:
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yield fixture
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@contextlib.contextmanager
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def _install_capture_fixture_on_item(request, capture_class):
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"""
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Context manager which creates a ``CaptureFixture`` instance and "installs" it on
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the item/node of the given request. Used by ``capsys`` and ``capfd``.
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The CaptureFixture is added as attribute of the item because it needs to accessed
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by ``CaptureManager`` during its ``pytest_runtest_*`` hooks.
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"""
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request.node._capture_fixture = fixture = CaptureFixture(capture_class, request)
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capmanager = request.config.pluginmanager.getplugin('capturemanager')
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# need to active this fixture right away in case it is being used by another fixture (setup phase)
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# if this fixture is being used only by a test function (call phase), then we wouldn't need this
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# activation, but it doesn't hurt
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capmanager.activate_fixture(request.node)
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yield fixture
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fixture.close()
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del request.node._capture_fixture
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class CaptureFixture:
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def __init__(self, captureclass, request):
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self.captureclass = captureclass
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self.request = request
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def _start(self):
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self._capture = MultiCapture(out=True, err=True, in_=False,
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Capture=self.captureclass)
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self._capture.start_capturing()
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def close(self):
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cap = self.__dict__.pop("_capture", None)
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if cap is not None:
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self._outerr = cap.pop_outerr_to_orig()
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cap.stop_capturing()
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def readouterr(self):
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try:
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return self._capture.readouterr()
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except AttributeError:
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return self._outerr
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@contextlib.contextmanager
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def disabled(self):
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self._capture.suspend_capturing()
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capmanager = self.request.config.pluginmanager.getplugin('capturemanager')
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capmanager.suspend_global_capture(item=None, in_=False)
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try:
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yield
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finally:
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capmanager.resume_global_capture()
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self._capture.resume_capturing()
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def safe_text_dupfile(f, mode, default_encoding="UTF8"):
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""" return a open text file object that's a duplicate of f on the
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FD-level if possible.
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"""
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encoding = getattr(f, "encoding", None)
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try:
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fd = f.fileno()
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except Exception:
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if "b" not in getattr(f, "mode", "") and hasattr(f, "encoding"):
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# we seem to have a text stream, let's just use it
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return f
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else:
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newfd = os.dup(fd)
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if "b" not in mode:
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mode += "b"
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f = os.fdopen(newfd, mode, 0) # no buffering
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return EncodedFile(f, encoding or default_encoding)
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class EncodedFile(object):
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errors = "strict" # possibly needed by py3 code (issue555)
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def __init__(self, buffer, encoding):
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self.buffer = buffer
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self.encoding = encoding
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def write(self, obj):
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if isinstance(obj, six.text_type):
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obj = obj.encode(self.encoding, "replace")
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self.buffer.write(obj)
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def writelines(self, linelist):
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data = ''.join(linelist)
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self.write(data)
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@property
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def name(self):
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"""Ensure that file.name is a string."""
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return repr(self.buffer)
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def __getattr__(self, name):
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return getattr(object.__getattribute__(self, "buffer"), name)
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class MultiCapture(object):
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out = err = in_ = None
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def __init__(self, out=True, err=True, in_=True, Capture=None):
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if in_:
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self.in_ = Capture(0)
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if out:
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self.out = Capture(1)
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if err:
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self.err = Capture(2)
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def start_capturing(self):
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if self.in_:
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self.in_.start()
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if self.out:
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self.out.start()
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if self.err:
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self.err.start()
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def pop_outerr_to_orig(self):
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""" pop current snapshot out/err capture and flush to orig streams. """
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out, err = self.readouterr()
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if out:
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self.out.writeorg(out)
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if err:
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self.err.writeorg(err)
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return out, err
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def suspend_capturing(self, in_=False):
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if self.out:
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self.out.suspend()
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if self.err:
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self.err.suspend()
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if in_ and self.in_:
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self.in_.suspend()
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self._in_suspended = True
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def resume_capturing(self):
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if self.out:
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self.out.resume()
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if self.err:
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self.err.resume()
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if hasattr(self, "_in_suspended"):
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self.in_.resume()
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del self._in_suspended
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def stop_capturing(self):
|
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""" stop capturing and reset capturing streams """
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if hasattr(self, '_reset'):
|
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raise ValueError("was already stopped")
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self._reset = True
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if self.out:
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self.out.done()
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if self.err:
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self.err.done()
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if self.in_:
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self.in_.done()
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def readouterr(self):
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""" return snapshot unicode value of stdout/stderr capturings. """
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return (self.out.snap() if self.out is not None else "",
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self.err.snap() if self.err is not None else "")
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|
|
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class NoCapture:
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__init__ = start = done = suspend = resume = lambda *args: None
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|
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class FDCapture:
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""" Capture IO to/from a given os-level filedescriptor. """
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def __init__(self, targetfd, tmpfile=None):
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self.targetfd = targetfd
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try:
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self.targetfd_save = os.dup(self.targetfd)
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except OSError:
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self.start = lambda: None
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self.done = lambda: None
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else:
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if targetfd == 0:
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assert not tmpfile, "cannot set tmpfile with stdin"
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tmpfile = open(os.devnull, "r")
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self.syscapture = SysCapture(targetfd)
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else:
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if tmpfile is None:
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f = TemporaryFile()
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with f:
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tmpfile = safe_text_dupfile(f, mode="wb+")
|
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if targetfd in patchsysdict:
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self.syscapture = SysCapture(targetfd, tmpfile)
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else:
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self.syscapture = NoCapture()
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self.tmpfile = tmpfile
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self.tmpfile_fd = tmpfile.fileno()
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|
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def __repr__(self):
|
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return "<FDCapture %s oldfd=%s>" % (self.targetfd, self.targetfd_save)
|
|
|
|
def start(self):
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|
""" Start capturing on targetfd using memorized tmpfile. """
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try:
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os.fstat(self.targetfd_save)
|
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except (AttributeError, OSError):
|
|
raise ValueError("saved filedescriptor not valid anymore")
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os.dup2(self.tmpfile_fd, self.targetfd)
|
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self.syscapture.start()
|
|
|
|
def snap(self):
|
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f = self.tmpfile
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f.seek(0)
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|
res = f.read()
|
|
if res:
|
|
enc = getattr(f, "encoding", None)
|
|
if enc and isinstance(res, bytes):
|
|
res = six.text_type(res, enc, "replace")
|
|
f.truncate(0)
|
|
f.seek(0)
|
|
return res
|
|
return ''
|
|
|
|
def done(self):
|
|
""" stop capturing, restore streams, return original capture file,
|
|
seeked to position zero. """
|
|
targetfd_save = self.__dict__.pop("targetfd_save")
|
|
os.dup2(targetfd_save, self.targetfd)
|
|
os.close(targetfd_save)
|
|
self.syscapture.done()
|
|
self.tmpfile.close()
|
|
|
|
def suspend(self):
|
|
self.syscapture.suspend()
|
|
os.dup2(self.targetfd_save, self.targetfd)
|
|
|
|
def resume(self):
|
|
self.syscapture.resume()
|
|
os.dup2(self.tmpfile_fd, self.targetfd)
|
|
|
|
def writeorg(self, data):
|
|
""" write to original file descriptor. """
|
|
if isinstance(data, six.text_type):
|
|
data = data.encode("utf8") # XXX use encoding of original stream
|
|
os.write(self.targetfd_save, data)
|
|
|
|
|
|
class SysCapture:
|
|
def __init__(self, fd, tmpfile=None):
|
|
name = patchsysdict[fd]
|
|
self._old = getattr(sys, name)
|
|
self.name = name
|
|
if tmpfile is None:
|
|
if name == "stdin":
|
|
tmpfile = DontReadFromInput()
|
|
else:
|
|
tmpfile = CaptureIO()
|
|
self.tmpfile = tmpfile
|
|
|
|
def start(self):
|
|
setattr(sys, self.name, self.tmpfile)
|
|
|
|
def snap(self):
|
|
f = self.tmpfile
|
|
res = f.getvalue()
|
|
f.truncate(0)
|
|
f.seek(0)
|
|
return res
|
|
|
|
def done(self):
|
|
setattr(sys, self.name, self._old)
|
|
del self._old
|
|
self.tmpfile.close()
|
|
|
|
def suspend(self):
|
|
setattr(sys, self.name, self._old)
|
|
|
|
def resume(self):
|
|
setattr(sys, self.name, self.tmpfile)
|
|
|
|
def writeorg(self, data):
|
|
self._old.write(data)
|
|
self._old.flush()
|
|
|
|
|
|
class DontReadFromInput:
|
|
"""Temporary stub class. Ideally when stdin is accessed, the
|
|
capturing should be turned off, with possibly all data captured
|
|
so far sent to the screen. This should be configurable, though,
|
|
because in automated test runs it is better to crash than
|
|
hang indefinitely.
|
|
"""
|
|
|
|
encoding = None
|
|
|
|
def read(self, *args):
|
|
raise IOError("reading from stdin while output is captured")
|
|
readline = read
|
|
readlines = read
|
|
__iter__ = read
|
|
|
|
def fileno(self):
|
|
raise UnsupportedOperation("redirected stdin is pseudofile, "
|
|
"has no fileno()")
|
|
|
|
def isatty(self):
|
|
return False
|
|
|
|
def close(self):
|
|
pass
|
|
|
|
@property
|
|
def buffer(self):
|
|
if sys.version_info >= (3, 0):
|
|
return self
|
|
else:
|
|
raise AttributeError('redirected stdin has no attribute buffer')
|
|
|
|
|
|
def _colorama_workaround():
|
|
"""
|
|
Ensure colorama is imported so that it attaches to the correct stdio
|
|
handles on Windows.
|
|
|
|
colorama uses the terminal on import time. So if something does the
|
|
first import of colorama while I/O capture is active, colorama will
|
|
fail in various ways.
|
|
"""
|
|
|
|
if not sys.platform.startswith('win32'):
|
|
return
|
|
try:
|
|
import colorama # noqa
|
|
except ImportError:
|
|
pass
|
|
|
|
|
|
def _readline_workaround():
|
|
"""
|
|
Ensure readline is imported so that it attaches to the correct stdio
|
|
handles on Windows.
|
|
|
|
Pdb uses readline support where available--when not running from the Python
|
|
prompt, the readline module is not imported until running the pdb REPL. If
|
|
running pytest with the --pdb option this means the readline module is not
|
|
imported until after I/O capture has been started.
|
|
|
|
This is a problem for pyreadline, which is often used to implement readline
|
|
support on Windows, as it does not attach to the correct handles for stdout
|
|
and/or stdin if they have been redirected by the FDCapture mechanism. This
|
|
workaround ensures that readline is imported before I/O capture is setup so
|
|
that it can attach to the actual stdin/out for the console.
|
|
|
|
See https://github.com/pytest-dev/pytest/pull/1281
|
|
"""
|
|
|
|
if not sys.platform.startswith('win32'):
|
|
return
|
|
try:
|
|
import readline # noqa
|
|
except ImportError:
|
|
pass
|
|
|
|
|
|
def _py36_windowsconsoleio_workaround(stream):
|
|
"""
|
|
Python 3.6 implemented unicode console handling for Windows. This works
|
|
by reading/writing to the raw console handle using
|
|
``{Read,Write}ConsoleW``.
|
|
|
|
The problem is that we are going to ``dup2`` over the stdio file
|
|
descriptors when doing ``FDCapture`` and this will ``CloseHandle`` the
|
|
handles used by Python to write to the console. Though there is still some
|
|
weirdness and the console handle seems to only be closed randomly and not
|
|
on the first call to ``CloseHandle``, or maybe it gets reopened with the
|
|
same handle value when we suspend capturing.
|
|
|
|
The workaround in this case will reopen stdio with a different fd which
|
|
also means a different handle by replicating the logic in
|
|
"Py_lifecycle.c:initstdio/create_stdio".
|
|
|
|
:param stream: in practice ``sys.stdout`` or ``sys.stderr``, but given
|
|
here as parameter for unittesting purposes.
|
|
|
|
See https://github.com/pytest-dev/py/issues/103
|
|
"""
|
|
if not sys.platform.startswith('win32') or sys.version_info[:2] < (3, 6):
|
|
return
|
|
|
|
# bail out if ``stream`` doesn't seem like a proper ``io`` stream (#2666)
|
|
if not hasattr(stream, 'buffer'):
|
|
return
|
|
|
|
buffered = hasattr(stream.buffer, 'raw')
|
|
raw_stdout = stream.buffer.raw if buffered else stream.buffer
|
|
|
|
if not isinstance(raw_stdout, io._WindowsConsoleIO):
|
|
return
|
|
|
|
def _reopen_stdio(f, mode):
|
|
if not buffered and mode[0] == 'w':
|
|
buffering = 0
|
|
else:
|
|
buffering = -1
|
|
|
|
return io.TextIOWrapper(
|
|
open(os.dup(f.fileno()), mode, buffering),
|
|
f.encoding,
|
|
f.errors,
|
|
f.newlines,
|
|
f.line_buffering)
|
|
|
|
sys.__stdin__ = sys.stdin = _reopen_stdio(sys.stdin, 'rb')
|
|
sys.__stdout__ = sys.stdout = _reopen_stdio(sys.stdout, 'wb')
|
|
sys.__stderr__ = sys.stderr = _reopen_stdio(sys.stderr, 'wb')
|