"""Access and control log capturing."""
import io
import logging
import os
import re
from contextlib import contextmanager
from contextlib import nullcontext
from io import StringIO
from pathlib import Path
from typing import AbstractSet
from typing import Dict
from typing import Generator
from typing import List
from typing import Mapping
from typing import Optional
from typing import Tuple
from typing import TYPE_CHECKING
from typing import TypeVar
from typing import Union
from _pytest import nodes
from _pytest._io import TerminalWriter
from _pytest.capture import CaptureManager
from _pytest.compat import final
from _pytest.config import _strtobool
from _pytest.config import Config
from _pytest.config import create_terminal_writer
from _pytest.config import hookimpl
from _pytest.config import UsageError
from _pytest.config.argparsing import Parser
from _pytest.deprecated import check_ispytest
from _pytest.fixtures import fixture
from _pytest.fixtures import FixtureRequest
from _pytest.main import Session
from _pytest.stash import StashKey
from _pytest.terminal import TerminalReporter
if TYPE_CHECKING:
logging_StreamHandler = logging.StreamHandler[StringIO]
from typing_extensions import Literal
else:
logging_StreamHandler = logging.StreamHandler
DEFAULT_LOG_FORMAT = "%(levelname)-8s %(name)s:%(filename)s:%(lineno)d %(message)s"
DEFAULT_LOG_DATE_FORMAT = "%H:%M:%S"
_ANSI_ESCAPE_SEQ = re.compile(r"\x1b\[[\d;]+m")
caplog_handler_key = StashKey["LogCaptureHandler"]()
caplog_records_key = StashKey[Dict[str, List[logging.LogRecord]]]()
def _remove_ansi_escape_sequences(text: str) -> str:
return _ANSI_ESCAPE_SEQ.sub("", text)
class ColoredLevelFormatter(logging.Formatter):
"""A logging formatter which colorizes the %(levelname)..s part of the
log format passed to __init__."""
LOGLEVEL_COLOROPTS: Mapping[int, AbstractSet[str]] = {
logging.CRITICAL: {"red"},
logging.ERROR: {"red", "bold"},
logging.WARNING: {"yellow"},
logging.WARN: {"yellow"},
logging.INFO: {"green"},
logging.DEBUG: {"purple"},
logging.NOTSET: set(),
}
LEVELNAME_FMT_REGEX = re.compile(r"%\(levelname\)([+-.]?\d*(?:\.\d+)?s)")
def __init__(self, terminalwriter: TerminalWriter, *args, **kwargs) -> None:
super().__init__(*args, **kwargs)
self._terminalwriter = terminalwriter
self._original_fmt = self._style._fmt
self._level_to_fmt_mapping: Dict[int, str] = {}
for level, color_opts in self.LOGLEVEL_COLOROPTS.items():
self.add_color_level(level, *color_opts)
def add_color_level(self, level: int, *color_opts: str) -> None:
"""Add or update color opts for a log level.
:param level:
Log level to apply a style to, e.g. ``logging.INFO``.
:param color_opts:
ANSI escape sequence color options. Capitalized colors indicates
background color, i.e. ``'green', 'Yellow', 'bold'`` will give bold
green text on yellow background.
.. warning::
This is an experimental API.
"""
assert self._fmt is not None
levelname_fmt_match = self.LEVELNAME_FMT_REGEX.search(self._fmt)
if not levelname_fmt_match:
return
levelname_fmt = levelname_fmt_match.group()
formatted_levelname = levelname_fmt % {"levelname": logging.getLevelName(level)}
# add ANSI escape sequences around the formatted levelname
color_kwargs = {name: True for name in color_opts}
colorized_formatted_levelname = self._terminalwriter.markup(
formatted_levelname, **color_kwargs
)
self._level_to_fmt_mapping[level] = self.LEVELNAME_FMT_REGEX.sub(
colorized_formatted_levelname, self._fmt
)
def format(self, record: logging.LogRecord) -> str:
fmt = self._level_to_fmt_mapping.get(record.levelno, self._original_fmt)
self._style._fmt = fmt
return super().format(record)
class PercentStyleMultiline(logging.PercentStyle):
"""A logging style with special support for multiline messages.
If the message of a record consists of multiple lines, this style
formats the message as if each line were logged separately.
"""
def __init__(self, fmt: str, auto_indent: Union[int, str, bool, None]) -> None:
super().__init__(fmt)
self._auto_indent = self._get_auto_indent(auto_indent)
@staticmethod
def _get_auto_indent(auto_indent_option: Union[int, str, bool, None]) -> int:
"""Determine the current auto indentation setting.
Specify auto indent behavior (on/off/fixed) by passing in
extra={"auto_indent": [value]} to the call to logging.log() or
using a --log-auto-indent [value] command line or the
log_auto_indent [value] config option.
Default behavior is auto-indent off.
Using the string "True" or "on" or the boolean True as the value
turns auto indent on, using the string "False" or "off" or the
boolean False or the int 0 turns it off, and specifying a
positive integer fixes the indentation position to the value
specified.
Any other values for the option are invalid, and will silently be
converted to the default.
:param None|bool|int|str auto_indent_option:
User specified option for indentation from command line, config
or extra kwarg. Accepts int, bool or str. str option accepts the
same range of values as boolean config options, as well as
positive integers represented in str form.
:returns:
Indentation value, which can be
-1 (automatically determine indentation) or
0 (auto-indent turned off) or
>0 (explicitly set indentation position).
"""
if auto_indent_option is None:
return 0
elif isinstance(auto_indent_option, bool):
if auto_indent_option:
return -1
else:
return 0
elif isinstance(auto_indent_option, int):
return int(auto_indent_option)
elif isinstance(auto_indent_option, str):
try:
return int(auto_indent_option)
except ValueError:
pass
try:
if _strtobool(auto_indent_option):
return -1
except ValueError:
return 0
return 0
def format(self, record: logging.LogRecord) -> str:
if "\n" in record.message:
if hasattr(record, "auto_indent"):
# Passed in from the "extra={}" kwarg on the call to logging.log().
auto_indent = self._get_auto_indent(record.auto_indent) # type: ignore[attr-defined]
else:
auto_indent = self._auto_indent
if auto_indent:
lines = record.message.splitlines()
formatted = self._fmt % {**record.__dict__, "message": lines[0]}
if auto_indent < 0:
indentation = _remove_ansi_escape_sequences(formatted).find(
lines[0]
)
else:
# Optimizes logging by allowing a fixed indentation.
indentation = auto_indent
lines[0] = formatted
return ("\n" + " " * indentation).join(lines)
return self._fmt % record.__dict__
def get_option_ini(config: Config, *names: str):
for name in names:
ret = config.getoption(name) # 'default' arg won't work as expected
if ret is None:
ret = config.getini(name)
if ret:
return ret
def pytest_addoption(parser: Parser) -> None:
"""Add options to control log capturing."""
group = parser.getgroup("logging")
def add_option_ini(option, dest, default=None, type=None, **kwargs):
parser.addini(
dest, default=default, type=type, help="Default value for " + option
)
group.addoption(option, dest=dest, **kwargs)
add_option_ini(
"--log-level",
dest="log_level",
default=None,
metavar="LEVEL",
help=(
"Level of messages to catch/display."
" Not set by default, so it depends on the root/parent log handler's"
' effective level, where it is "WARNING" by default.'
),
)
add_option_ini(
"--log-format",
dest="log_format",
default=DEFAULT_LOG_FORMAT,
help="Log format used by the logging module",
)
add_option_ini(
"--log-date-format",
dest="log_date_format",
default=DEFAULT_LOG_DATE_FORMAT,
help="Log date format used by the logging module",
)
parser.addini(
"log_cli",
default=False,
type="bool",
help='Enable log display during test run (also known as "live logging")',
)
add_option_ini(
"--log-cli-level", dest="log_cli_level", default=None, help="CLI logging level"
)
add_option_ini(
"--log-cli-format",
dest="log_cli_format",
default=None,
help="Log format used by the logging module",
)
add_option_ini(
"--log-cli-date-format",
dest="log_cli_date_format",
default=None,
help="Log date format used by the logging module",
)
add_option_ini(
"--log-file",
dest="log_file",
default=None,
help="Path to a file when logging will be written to",
)
add_option_ini(
"--log-file-level",
dest="log_file_level",
default=None,
help="Log file logging level",
)
add_option_ini(
"--log-file-format",
dest="log_file_format",
default=DEFAULT_LOG_FORMAT,
help="Log format used by the logging module",
)
add_option_ini(
"--log-file-date-format",
dest="log_file_date_format",
default=DEFAULT_LOG_DATE_FORMAT,
help="Log date format used by the logging module",
)
add_option_ini(
"--log-auto-indent",
dest="log_auto_indent",
default=None,
help="Auto-indent multiline messages passed to the logging module. Accepts true|on, false|off or an integer.",
)
_HandlerType = TypeVar("_HandlerType", bound=logging.Handler)
# Not using @contextmanager for performance reasons.
class catching_logs:
"""Context manager that prepares the whole logging machinery properly."""
__slots__ = ("handler", "level", "orig_level")
def __init__(self, handler: _HandlerType, level: Optional[int] = None) -> None:
self.handler = handler
self.level = level
def __enter__(self):
root_logger = logging.getLogger()
if self.level is not None:
self.handler.setLevel(self.level)
root_logger.addHandler(self.handler)
if self.level is not None:
self.orig_level = root_logger.level
root_logger.setLevel(min(self.orig_level, self.level))
return self.handler
def __exit__(self, type, value, traceback):
root_logger = logging.getLogger()
if self.level is not None:
root_logger.setLevel(self.orig_level)
root_logger.removeHandler(self.handler)
class LogCaptureHandler(logging_StreamHandler):
"""A logging handler that stores log records and the log text."""
def __init__(self) -> None:
"""Create a new log handler."""
super().__init__(StringIO())
self.records: List[logging.LogRecord] = []
def emit(self, record: logging.LogRecord) -> None:
"""Keep the log records in a list in addition to the log text."""
self.records.append(record)
super().emit(record)
def reset(self) -> None:
self.records = []
self.stream = StringIO()
def clear(self) -> None:
self.records.clear()
self.stream = StringIO()
def handleError(self, record: logging.LogRecord) -> None:
if logging.raiseExceptions:
# Fail the test if the log message is bad (emit failed).
# The default behavior of logging is to print "Logging error"
# to stderr with the call stack and some extra details.
# pytest wants to make such mistakes visible during testing.
raise
[документация]@final
class LogCaptureFixture:
"""Provides access and control of log capturing."""
def __init__(self, item: nodes.Node, *, _ispytest: bool = False) -> None:
check_ispytest(_ispytest)
self._item = item
self._initial_handler_level: Optional[int] = None
# Dict of log name -> log level.
self._initial_logger_levels: Dict[Optional[str], int] = {}
def _finalize(self) -> None:
"""Finalize the fixture.
This restores the log levels changed by :meth:`set_level`.
"""
# Restore log levels.
if self._initial_handler_level is not None:
self.handler.setLevel(self._initial_handler_level)
for logger_name, level in self._initial_logger_levels.items():
logger = logging.getLogger(logger_name)
logger.setLevel(level)
@property
def handler(self) -> LogCaptureHandler:
"""Get the logging handler used by the fixture."""
return self._item.stash[caplog_handler_key]
[документация] def get_records(
self, when: "Literal['setup', 'call', 'teardown']"
) -> List[logging.LogRecord]:
"""Get the logging records for one of the possible test phases.
:param when:
Which test phase to obtain the records from.
Valid values are: "setup", "call" and "teardown".
:returns: The list of captured records at the given stage.
.. versionadded:: 3.4
"""
return self._item.stash[caplog_records_key].get(when, [])
@property
def text(self) -> str:
"""The formatted log text."""
return _remove_ansi_escape_sequences(self.handler.stream.getvalue())
@property
def records(self) -> List[logging.LogRecord]:
"""The list of log records."""
return self.handler.records
@property
def record_tuples(self) -> List[Tuple[str, int, str]]:
"""A list of a stripped down version of log records intended
for use in assertion comparison.
The format of the tuple is:
(logger_name, log_level, message)
"""
return [(r.name, r.levelno, r.getMessage()) for r in self.records]
@property
def messages(self) -> List[str]:
"""A list of format-interpolated log messages.
Unlike 'records', which contains the format string and parameters for
interpolation, log messages in this list are all interpolated.
Unlike 'text', which contains the output from the handler, log
messages in this list are unadorned with levels, timestamps, etc,
making exact comparisons more reliable.
Note that traceback or stack info (from :func:`logging.exception` or
the `exc_info` or `stack_info` arguments to the logging functions) is
not included, as this is added by the formatter in the handler.
.. versionadded:: 3.7
"""
return [r.getMessage() for r in self.records]
[документация] def clear(self) -> None:
"""Reset the list of log records and the captured log text."""
self.handler.clear()
[документация] def set_level(self, level: Union[int, str], logger: Optional[str] = None) -> None:
"""Set the level of a logger for the duration of a test.
.. versionchanged:: 3.4
The levels of the loggers changed by this function will be
restored to their initial values at the end of the test.
:param level: The level.
:param logger: The logger to update. If not given, the root logger.
"""
logger_obj = logging.getLogger(logger)
# Save the original log-level to restore it during teardown.
self._initial_logger_levels.setdefault(logger, logger_obj.level)
logger_obj.setLevel(level)
if self._initial_handler_level is None:
self._initial_handler_level = self.handler.level
self.handler.setLevel(level)
[документация] @contextmanager
def at_level(
self, level: Union[int, str], logger: Optional[str] = None
) -> Generator[None, None, None]:
"""Context manager that sets the level for capturing of logs. After
the end of the 'with' statement the level is restored to its original
value.
:param level: The level.
:param logger: The logger to update. If not given, the root logger.
"""
logger_obj = logging.getLogger(logger)
orig_level = logger_obj.level
logger_obj.setLevel(level)
handler_orig_level = self.handler.level
self.handler.setLevel(level)
try:
yield
finally:
logger_obj.setLevel(orig_level)
self.handler.setLevel(handler_orig_level)
[документация]@fixture
def caplog(request: FixtureRequest) -> Generator[LogCaptureFixture, None, None]:
"""Access and control log capturing.
Captured logs are available through the following properties/methods::
* caplog.messages -> list of format-interpolated log messages
* caplog.text -> string containing formatted log output
* caplog.records -> list of logging.LogRecord instances
* caplog.record_tuples -> list of (logger_name, level, message) tuples
* caplog.clear() -> clear captured records and formatted log output string
"""
result = LogCaptureFixture(request.node, _ispytest=True)
yield result
result._finalize()
def get_log_level_for_setting(config: Config, *setting_names: str) -> Optional[int]:
for setting_name in setting_names:
log_level = config.getoption(setting_name)
if log_level is None:
log_level = config.getini(setting_name)
if log_level:
break
else:
return None
if isinstance(log_level, str):
log_level = log_level.upper()
try:
return int(getattr(logging, log_level, log_level))
except ValueError as e:
# Python logging does not recognise this as a logging level
raise UsageError(
"'{}' is not recognized as a logging level name for "
"'{}'. Please consider passing the "
"logging level num instead.".format(log_level, setting_name)
) from e
# run after terminalreporter/capturemanager are configured
@hookimpl(trylast=True)
def pytest_configure(config: Config) -> None:
config.pluginmanager.register(LoggingPlugin(config), "logging-plugin")
class LoggingPlugin:
"""Attaches to the logging module and captures log messages for each test."""
def __init__(self, config: Config) -> None:
"""Create a new plugin to capture log messages.
The formatter can be safely shared across all handlers so
create a single one for the entire test session here.
"""
self._config = config
# Report logging.
self.formatter = self._create_formatter(
get_option_ini(config, "log_format"),
get_option_ini(config, "log_date_format"),
get_option_ini(config, "log_auto_indent"),
)
self.log_level = get_log_level_for_setting(config, "log_level")
self.caplog_handler = LogCaptureHandler()
self.caplog_handler.setFormatter(self.formatter)
self.report_handler = LogCaptureHandler()
self.report_handler.setFormatter(self.formatter)
# File logging.
self.log_file_level = get_log_level_for_setting(config, "log_file_level")
log_file = get_option_ini(config, "log_file") or os.devnull
if log_file != os.devnull:
directory = os.path.dirname(os.path.abspath(log_file))
if not os.path.isdir(directory):
os.makedirs(directory)
self.log_file_handler = _FileHandler(log_file, mode="w", encoding="UTF-8")
log_file_format = get_option_ini(config, "log_file_format", "log_format")
log_file_date_format = get_option_ini(
config, "log_file_date_format", "log_date_format"
)
log_file_formatter = logging.Formatter(
log_file_format, datefmt=log_file_date_format
)
self.log_file_handler.setFormatter(log_file_formatter)
# CLI/live logging.
self.log_cli_level = get_log_level_for_setting(
config, "log_cli_level", "log_level"
)
if self._log_cli_enabled():
terminal_reporter = config.pluginmanager.get_plugin("terminalreporter")
capture_manager = config.pluginmanager.get_plugin("capturemanager")
# if capturemanager plugin is disabled, live logging still works.
self.log_cli_handler: Union[
_LiveLoggingStreamHandler, _LiveLoggingNullHandler
] = _LiveLoggingStreamHandler(terminal_reporter, capture_manager)
else:
self.log_cli_handler = _LiveLoggingNullHandler()
log_cli_formatter = self._create_formatter(
get_option_ini(config, "log_cli_format", "log_format"),
get_option_ini(config, "log_cli_date_format", "log_date_format"),
get_option_ini(config, "log_auto_indent"),
)
self.log_cli_handler.setFormatter(log_cli_formatter)
def _create_formatter(self, log_format, log_date_format, auto_indent):
# Color option doesn't exist if terminal plugin is disabled.
color = getattr(self._config.option, "color", "no")
if color != "no" and ColoredLevelFormatter.LEVELNAME_FMT_REGEX.search(
log_format
):
formatter: logging.Formatter = ColoredLevelFormatter(
create_terminal_writer(self._config), log_format, log_date_format
)
else:
formatter = logging.Formatter(log_format, log_date_format)
formatter._style = PercentStyleMultiline(
formatter._style._fmt, auto_indent=auto_indent
)
return formatter
def set_log_path(self, fname: str) -> None:
"""Set the filename parameter for Logging.FileHandler().
Creates parent directory if it does not exist.
.. warning::
This is an experimental API.
"""
fpath = Path(fname)
if not fpath.is_absolute():
fpath = self._config.rootpath / fpath
if not fpath.parent.exists():
fpath.parent.mkdir(exist_ok=True, parents=True)
# https://github.com/python/mypy/issues/11193
stream: io.TextIOWrapper = fpath.open(mode="w", encoding="UTF-8") # type: ignore[assignment]
old_stream = self.log_file_handler.setStream(stream)
if old_stream:
old_stream.close()
def _log_cli_enabled(self):
"""Return whether live logging is enabled."""
enabled = self._config.getoption(
"--log-cli-level"
) is not None or self._config.getini("log_cli")
if not enabled:
return False
terminal_reporter = self._config.pluginmanager.get_plugin("terminalreporter")
if terminal_reporter is None:
# terminal reporter is disabled e.g. by pytest-xdist.
return False
return True
@hookimpl(hookwrapper=True, tryfirst=True)
def pytest_sessionstart(self) -> Generator[None, None, None]:
self.log_cli_handler.set_when("sessionstart")
with catching_logs(self.log_cli_handler, level=self.log_cli_level):
with catching_logs(self.log_file_handler, level=self.log_file_level):
yield
@hookimpl(hookwrapper=True, tryfirst=True)
def pytest_collection(self) -> Generator[None, None, None]:
self.log_cli_handler.set_when("collection")
with catching_logs(self.log_cli_handler, level=self.log_cli_level):
with catching_logs(self.log_file_handler, level=self.log_file_level):
yield
@hookimpl(hookwrapper=True)
def pytest_runtestloop(self, session: Session) -> Generator[None, None, None]:
if session.config.option.collectonly:
yield
return
if self._log_cli_enabled() and self._config.getoption("verbose") < 1:
# The verbose flag is needed to avoid messy test progress output.
self._config.option.verbose = 1
with catching_logs(self.log_cli_handler, level=self.log_cli_level):
with catching_logs(self.log_file_handler, level=self.log_file_level):
yield # Run all the tests.
@hookimpl
def pytest_runtest_logstart(self) -> None:
self.log_cli_handler.reset()
self.log_cli_handler.set_when("start")
@hookimpl
def pytest_runtest_logreport(self) -> None:
self.log_cli_handler.set_when("logreport")
def _runtest_for(self, item: nodes.Item, when: str) -> Generator[None, None, None]:
"""Implement the internals of the pytest_runtest_xxx() hooks."""
with catching_logs(
self.caplog_handler,
level=self.log_level,
) as caplog_handler, catching_logs(
self.report_handler,
level=self.log_level,
) as report_handler:
caplog_handler.reset()
report_handler.reset()
item.stash[caplog_records_key][when] = caplog_handler.records
item.stash[caplog_handler_key] = caplog_handler
yield
log = report_handler.stream.getvalue().strip()
item.add_report_section(when, "log", log)
@hookimpl(hookwrapper=True)
def pytest_runtest_setup(self, item: nodes.Item) -> Generator[None, None, None]:
self.log_cli_handler.set_when("setup")
empty: Dict[str, List[logging.LogRecord]] = {}
item.stash[caplog_records_key] = empty
yield from self._runtest_for(item, "setup")
@hookimpl(hookwrapper=True)
def pytest_runtest_call(self, item: nodes.Item) -> Generator[None, None, None]:
self.log_cli_handler.set_when("call")
yield from self._runtest_for(item, "call")
@hookimpl(hookwrapper=True)
def pytest_runtest_teardown(self, item: nodes.Item) -> Generator[None, None, None]:
self.log_cli_handler.set_when("teardown")
yield from self._runtest_for(item, "teardown")
del item.stash[caplog_records_key]
del item.stash[caplog_handler_key]
@hookimpl
def pytest_runtest_logfinish(self) -> None:
self.log_cli_handler.set_when("finish")
@hookimpl(hookwrapper=True, tryfirst=True)
def pytest_sessionfinish(self) -> Generator[None, None, None]:
self.log_cli_handler.set_when("sessionfinish")
with catching_logs(self.log_cli_handler, level=self.log_cli_level):
with catching_logs(self.log_file_handler, level=self.log_file_level):
yield
@hookimpl
def pytest_unconfigure(self) -> None:
# Close the FileHandler explicitly.
# (logging.shutdown might have lost the weakref?!)
self.log_file_handler.close()
class _FileHandler(logging.FileHandler):
"""A logging FileHandler with pytest tweaks."""
def handleError(self, record: logging.LogRecord) -> None:
# Handled by LogCaptureHandler.
pass
class _LiveLoggingStreamHandler(logging_StreamHandler):
"""A logging StreamHandler used by the live logging feature: it will
write a newline before the first log message in each test.
During live logging we must also explicitly disable stdout/stderr
capturing otherwise it will get captured and won't appear in the
terminal.
"""
# Officially stream needs to be a IO[str], but TerminalReporter
# isn't. So force it.
stream: TerminalReporter = None # type: ignore
def __init__(
self,
terminal_reporter: TerminalReporter,
capture_manager: Optional[CaptureManager],
) -> None:
super().__init__(stream=terminal_reporter) # type: ignore[arg-type]
self.capture_manager = capture_manager
self.reset()
self.set_when(None)
self._test_outcome_written = False
def reset(self) -> None:
"""Reset the handler; should be called before the start of each test."""
self._first_record_emitted = False
def set_when(self, when: Optional[str]) -> None:
"""Prepare for the given test phase (setup/call/teardown)."""
self._when = when
self._section_name_shown = False
if when == "start":
self._test_outcome_written = False
def emit(self, record: logging.LogRecord) -> None:
ctx_manager = (
self.capture_manager.global_and_fixture_disabled()
if self.capture_manager
else nullcontext()
)
with ctx_manager:
if not self._first_record_emitted:
self.stream.write("\n")
self._first_record_emitted = True
elif self._when in ("teardown", "finish"):
if not self._test_outcome_written:
self._test_outcome_written = True
self.stream.write("\n")
if not self._section_name_shown and self._when:
self.stream.section("live log " + self._when, sep="-", bold=True)
self._section_name_shown = True
super().emit(record)
def handleError(self, record: logging.LogRecord) -> None:
# Handled by LogCaptureHandler.
pass
class _LiveLoggingNullHandler(logging.NullHandler):
"""A logging handler used when live logging is disabled."""
def reset(self) -> None:
pass
def set_when(self, when: str) -> None:
pass
def handleError(self, record: logging.LogRecord) -> None:
# Handled by LogCaptureHandler.
pass