"""Coverage plugin for pytest.""" import argparse import os import warnings import coverage import pytest from . import compat from . import embed class CoverageError(Exception): """Indicates that our coverage is too low""" class PytestCovWarning(pytest.PytestWarning): """ The base for all pytest-cov warnings, never raised directly """ class CovDisabledWarning(PytestCovWarning): """Indicates that Coverage was manually disabled""" class CovReportWarning(PytestCovWarning): """Indicates that we failed to generate a report""" def validate_report(arg): file_choices = ['annotate', 'html', 'xml', 'lcov'] term_choices = ['term', 'term-missing'] term_modifier_choices = ['skip-covered'] all_choices = term_choices + file_choices values = arg.split(":", 1) report_type = values[0] if report_type not in all_choices + ['']: msg = f'invalid choice: "{arg}" (choose from "{all_choices}")' raise argparse.ArgumentTypeError(msg) if report_type == 'lcov' and coverage.version_info <= (6, 3): raise argparse.ArgumentTypeError('LCOV output is only supported with coverage.py >= 6.3') if len(values) == 1: return report_type, None report_modifier = values[1] if report_type in term_choices and report_modifier in term_modifier_choices: return report_type, report_modifier if report_type not in file_choices: msg = 'output specifier not supported for: "{}" (choose from "{}")'.format(arg, file_choices) raise argparse.ArgumentTypeError(msg) return values def validate_fail_under(num_str): try: value = int(num_str) except ValueError: try: value = float(num_str) except ValueError: raise argparse.ArgumentTypeError('An integer or float value is required.') if value > 100: raise argparse.ArgumentTypeError('Your desire for over-achievement is admirable but misplaced. ' 'The maximum value is 100. Perhaps write more integration tests?') return value def validate_context(arg): if coverage.version_info <= (5, 0): raise argparse.ArgumentTypeError('Contexts are only supported with coverage.py >= 5.x') if arg != "test": raise argparse.ArgumentTypeError('The only supported value is "test".') return arg class StoreReport(argparse.Action): def __call__(self, parser, namespace, values, option_string=None): report_type, file = values namespace.cov_report[report_type] = file def pytest_addoption(parser): """Add options to control coverage.""" group = parser.getgroup( 'cov', 'coverage reporting with distributed testing support') group.addoption('--cov', action='append', default=[], metavar='SOURCE', nargs='?', const=True, dest='cov_source', help='Path or package name to measure during execution (multi-allowed). ' 'Use --cov= to not do any source filtering and record everything.') group.addoption('--cov-reset', action='store_const', const=[], dest='cov_source', help='Reset cov sources accumulated in options so far. ') group.addoption('--cov-report', action=StoreReport, default={}, metavar='TYPE', type=validate_report, help='Type of report to generate: term, term-missing, ' 'annotate, html, xml, lcov (multi-allowed). ' 'term, term-missing may be followed by ":skip-covered". ' 'annotate, html, xml and lcov may be followed by ":DEST" ' 'where DEST specifies the output location. ' 'Use --cov-report= to not generate any output.') group.addoption('--cov-config', action='store', default='.coveragerc', metavar='PATH', help='Config file for coverage. Default: .coveragerc') group.addoption('--no-cov-on-fail', action='store_true', default=False, help='Do not report coverage if test run fails. ' 'Default: False') group.addoption('--no-cov', action='store_true', default=False, help='Disable coverage report completely (useful for debuggers). ' 'Default: False') group.addoption('--cov-fail-under', action='store', metavar='MIN', type=validate_fail_under, help='Fail if the total coverage is less than MIN.') group.addoption('--cov-append', action='store_true', default=False, help='Do not delete coverage but append to current. ' 'Default: False') group.addoption('--cov-branch', action='store_true', default=None, help='Enable branch coverage.') group.addoption('--cov-context', action='store', metavar='CONTEXT', type=validate_context, help='Dynamic contexts to use. "test" for now.') def _prepare_cov_source(cov_source): """ Prepare cov_source so that: --cov --cov=foobar is equivalent to --cov (cov_source=None) --cov=foo --cov=bar is equivalent to cov_source=['foo', 'bar'] """ return None if True in cov_source else [path for path in cov_source if path is not True] @pytest.hookimpl(tryfirst=True) def pytest_load_initial_conftests(early_config, parser, args): options = early_config.known_args_namespace no_cov = options.no_cov_should_warn = False for arg in args: arg = str(arg) if arg == '--no-cov': no_cov = True elif arg.startswith('--cov') and no_cov: options.no_cov_should_warn = True break if early_config.known_args_namespace.cov_source: plugin = CovPlugin(options, early_config.pluginmanager) early_config.pluginmanager.register(plugin, '_cov') class CovPlugin: """Use coverage package to produce code coverage reports. Delegates all work to a particular implementation based on whether this test process is centralised, a distributed master or a distributed worker. """ def __init__(self, options, pluginmanager, start=True, no_cov_should_warn=False): """Creates a coverage pytest plugin. We read the rc file that coverage uses to get the data file name. This is needed since we give coverage through it's API the data file name. """ # Our implementation is unknown at this time. self.pid = None self.cov_controller = None self.cov_report = compat.StringIO() self.cov_total = None self.failed = False self._started = False self._start_path = None self._disabled = False self.options = options is_dist = (getattr(options, 'numprocesses', False) or getattr(options, 'distload', False) or getattr(options, 'dist', 'no') != 'no') if getattr(options, 'no_cov', False): self._disabled = True return if not self.options.cov_report: self.options.cov_report = ['term'] elif len(self.options.cov_report) == 1 and '' in self.options.cov_report: self.options.cov_report = {} self.options.cov_source = _prepare_cov_source(self.options.cov_source) # import engine lazily here to avoid importing # it for unit tests that don't need it from . import engine if is_dist and start: self.start(engine.DistMaster) elif start: self.start(engine.Central) # worker is started in pytest hook def start(self, controller_cls, config=None, nodeid=None): if config is None: # fake config option for engine class Config: option = self.options config = Config() self.cov_controller = controller_cls( self.options.cov_source, self.options.cov_report, self.options.cov_config, self.options.cov_append, self.options.cov_branch, config, nodeid ) self.cov_controller.start() self._started = True self._start_path = os.getcwd() cov_config = self.cov_controller.cov.config if self.options.cov_fail_under is None and hasattr(cov_config, 'fail_under'): self.options.cov_fail_under = cov_config.fail_under def _is_worker(self, session): return getattr(session.config, 'workerinput', None) is not None def pytest_sessionstart(self, session): """At session start determine our implementation and delegate to it.""" if self.options.no_cov: # Coverage can be disabled because it does not cooperate with debuggers well. self._disabled = True return # import engine lazily here to avoid importing # it for unit tests that don't need it from . import engine self.pid = os.getpid() if self._is_worker(session): nodeid = ( session.config.workerinput.get('workerid', getattr(session, 'nodeid')) ) self.start(engine.DistWorker, session.config, nodeid) elif not self._started: self.start(engine.Central) if self.options.cov_context == 'test': session.config.pluginmanager.register(TestContextPlugin(self.cov_controller.cov), '_cov_contexts') @pytest.hookimpl(optionalhook=True) def pytest_configure_node(self, node): """Delegate to our implementation. Mark this hook as optional in case xdist is not installed. """ if not self._disabled: self.cov_controller.configure_node(node) @pytest.hookimpl(optionalhook=True) def pytest_testnodedown(self, node, error): """Delegate to our implementation. Mark this hook as optional in case xdist is not installed. """ if not self._disabled: self.cov_controller.testnodedown(node, error) def _should_report(self): return not (self.failed and self.options.no_cov_on_fail) def _failed_cov_total(self): cov_fail_under = self.options.cov_fail_under return cov_fail_under is not None and self.cov_total < cov_fail_under # we need to wrap pytest_runtestloop. by the time pytest_sessionfinish # runs, it's too late to set testsfailed @pytest.hookimpl(hookwrapper=True) def pytest_runtestloop(self, session): yield if self._disabled: return compat_session = compat.SessionWrapper(session) self.failed = bool(compat_session.testsfailed) if self.cov_controller is not None: self.cov_controller.finish() if not self._is_worker(session) and self._should_report(): # import coverage lazily here to avoid importing # it for unit tests that don't need it from coverage.misc import CoverageException try: self.cov_total = self.cov_controller.summary(self.cov_report) except CoverageException as exc: message = 'Failed to generate report: %s\n' % exc session.config.pluginmanager.getplugin("terminalreporter").write( 'WARNING: %s\n' % message, red=True, bold=True) warnings.warn(CovReportWarning(message)) self.cov_total = 0 assert self.cov_total is not None, 'Test coverage should never be `None`' if self._failed_cov_total() and not self.options.collectonly: # make sure we get the EXIT_TESTSFAILED exit code compat_session.testsfailed += 1 def pytest_terminal_summary(self, terminalreporter): if self._disabled: if self.options.no_cov_should_warn: message = 'Coverage disabled via --no-cov switch!' terminalreporter.write('WARNING: %s\n' % message, red=True, bold=True) warnings.warn(CovDisabledWarning(message)) return if self.cov_controller is None: return if self.cov_total is None: # we shouldn't report, or report generation failed (error raised above) return report = self.cov_report.getvalue() # Avoid undesirable new lines when output is disabled with "--cov-report=". if report: terminalreporter.write('\n' + report + '\n') if self.options.cov_fail_under is not None and self.options.cov_fail_under > 0: failed = self.cov_total < self.options.cov_fail_under markup = {'red': True, 'bold': True} if failed else {'green': True} message = ( '{fail}Required test coverage of {required}% {reached}. ' 'Total coverage: {actual:.2f}%\n' .format( required=self.options.cov_fail_under, actual=self.cov_total, fail="FAIL " if failed else "", reached="not reached" if failed else "reached" ) ) terminalreporter.write(message, **markup) def pytest_runtest_setup(self, item): if os.getpid() != self.pid: # test is run in another process than session, run # coverage manually embed.init() def pytest_runtest_teardown(self, item): embed.cleanup() @pytest.hookimpl(hookwrapper=True) def pytest_runtest_call(self, item): if (item.get_closest_marker('no_cover') or 'no_cover' in getattr(item, 'fixturenames', ())): self.cov_controller.pause() yield self.cov_controller.resume() else: yield class TestContextPlugin: def __init__(self, cov): self.cov = cov def pytest_runtest_setup(self, item): self.switch_context(item, 'setup') def pytest_runtest_teardown(self, item): self.switch_context(item, 'teardown') def pytest_runtest_call(self, item): self.switch_context(item, 'run') def switch_context(self, item, when): context = f"{item.nodeid}|{when}" self.cov.switch_context(context) os.environ['COV_CORE_CONTEXT'] = context @pytest.fixture def no_cover(): """A pytest fixture to disable coverage.""" pass @pytest.fixture def cov(request): """A pytest fixture to provide access to the underlying coverage object.""" # Check with hasplugin to avoid getplugin exception in older pytest. if request.config.pluginmanager.hasplugin('_cov'): plugin = request.config.pluginmanager.getplugin('_cov') if plugin.cov_controller: return plugin.cov_controller.cov return None def pytest_configure(config): config.addinivalue_line("markers", "no_cover: disable coverage for this test.")