def _should_use_virtualenv() -> bool:
import packaging.requirements
# virtualenv might be incompatible if it was installed separately
# from build. This verifies that virtualenv and all of its
# dependencies are installed as specified by build.
return virtualenv is not None and not any(
packaging.requirements.Requirement(d[1]).name == 'virtualenv'
for d in build.check_dependency('build[virtualenv]') if len(d) > 1)
def _should_use_virtualenv(self): # type: () -> Optional[bool]
# virtualenv might be incompatible if it was installed separately
# from build. This verifies that virtualenv and all of its
# dependencies are installed as specified by build.
if self._has_virtualenv is None:
self.__class__._has_virtualenv = virtualenv is not None and not any(
packaging.requirements.Requirement(d[1]).name == 'virtualenv'
for d in build.check_dependency('build[virtualenv]')
if len(d) > 1
)
return self._has_virtualenv
def test_check_dependency(monkeypatch, requirement_string, expected):
monkeypatch.setattr(importlib_metadata, 'Distribution', MockDistribution)
assert next(build.check_dependency(requirement_string), None) == expected
