def safe_exists(path: Path) -> bool:
# This can throw on paths that contain characters unrepresentable at the OS level,
# or with invalid syntax on Windows (https://bugs.python.org/issue35306)
try:
return path.exists()
except OSError:
return False
def resolve_collection_argument(
invocation_dir: py.path.local,
arg: str,
*,
as_pypath: bool = False) -> Tuple[py.path.local, List[str]]:
"""Parse path arguments optionally containing selection parts and return (fspath, names).
Command-line arguments can point to files and/or directories, and optionally contain
parts for specific tests selection, for example:
"pkg/tests/test_foo.py::TestClass::test_foo"
This function ensures the path exists, and returns a tuple:
(py.path.path("/full/path/to/pkg/tests/test_foo.py"), ["TestClass", "test_foo"])
When as_pypath is True, expects that the command-line argument actually contains
module paths instead of file-system paths:
"pkg.tests.test_foo::TestClass::test_foo"
In which case we search sys.path for a matching module, and then return the *path* to the
found module.
If the path doesn't exist, raise UsageError.
If the path is a directory and selection parts are present, raise UsageError.
"""
strpath, *parts = str(arg).split("::")
if as_pypath:
strpath = search_pypath(strpath)
fspath = Path(str(invocation_dir), strpath)
fspath = absolutepath(fspath)
if not fspath.exists():
msg = ("module or package not found: {arg} (missing __init__.py?)"
if as_pypath else "file or directory not found: {arg}")
raise UsageError(msg.format(arg=arg))
if parts and fspath.is_dir():
msg = ("package argument cannot contain :: selection parts: {arg}"
if as_pypath else
"directory argument cannot contain :: selection parts: {arg}")
raise UsageError(msg.format(arg=arg))
return py.path.local(str(fspath)), parts
