Create parent directories if necessary

src/filelock/_soft.py

@@ -7,14 +7,15 @@
 from pathlib import Path
 
 from ._api import BaseFileLock
-from ._util import raise_on_not_writable_file
+from ._util import ensure_directory_exists, raise_on_not_writable_file
 
 
 class SoftFileLock(BaseFileLock):
     """Simply watches the existence of the lock file."""
 
     def _acquire(self) -> None:
         raise_on_not_writable_file(self.lock_file)
+        ensure_directory_exists(self.lock_file)
         # first check for exists and read-only mode as the open will mask this case as EEXIST
         flags = (
             os.O_WRONLY  # open for writing only

src/filelock/_unix.py

@@ -7,6 +7,7 @@
 from typing import cast
 
 from ._api import BaseFileLock
+from ._util import ensure_directory_exists
 
 #: a flag to indicate if the fcntl API is available
 has_fcntl = False
@@ -33,6 +34,7 @@ class UnixFileLock(BaseFileLock):
         """Uses the :func:`fcntl.flock` to hard lock the lock file on unix systems."""
 
         def _acquire(self) -> None:
+            ensure_directory_exists(self.lock_file)
             open_flags = os.O_RDWR | os.O_CREAT | os.O_TRUNC
             fd = os.open(self.lock_file, open_flags, self._context.mode)
             with suppress(PermissionError):  # This locked is not owned by this UID

src/filelock/_util.py

@@ -4,6 +4,7 @@
 import stat
 import sys
 from errno import EACCES, EISDIR
+from pathlib import Path
 
 
 def raise_on_not_writable_file(filename: str) -> None:
@@ -32,6 +33,15 @@ def raise_on_not_writable_file(filename: str) -> None:
                 raise IsADirectoryError(EISDIR, "Is a directory", filename)
 
 
+def ensure_directory_exists(filename: Path | str) -> None:
+    """
+    Ensure the directory containing the file exists (create it if necessary)
+    :param filename: file.
+    """
+    Path(filename).parent.mkdir(parents=True, exist_ok=True)
+
+
 __all__ = [
     "raise_on_not_writable_file",
+    "ensure_directory_exists",
 ]

src/filelock/_windows.py

@@ -8,7 +8,7 @@
 from typing import cast
 
 from ._api import BaseFileLock
-from ._util import raise_on_not_writable_file
+from ._util import ensure_directory_exists, raise_on_not_writable_file
 
 if sys.platform == "win32":  # pragma: win32 cover
     import msvcrt
@@ -18,6 +18,7 @@ class WindowsFileLock(BaseFileLock):
 
         def _acquire(self) -> None:
             raise_on_not_writable_file(self.lock_file)
+            ensure_directory_exists(self.lock_file)
             flags = (
                 os.O_RDWR  # open for read and write
                 | os.O_CREAT  # create file if not exists

tests/test_filelock.py

@@ -23,27 +23,20 @@
     from pytest_mock import MockerFixture
 
 
-@pytest.mark.parametrize(
-    ("lock_type", "path_type"),
-    [
-        (FileLock, str),
-        (FileLock, PurePath),
-        (FileLock, Path),
-        (SoftFileLock, str),
-        (SoftFileLock, PurePath),
-        (SoftFileLock, Path),
-    ],
-)
+@pytest.mark.parametrize("lock_type", [FileLock, SoftFileLock])
+@pytest.mark.parametrize("path_type", [str, PurePath, Path])
+@pytest.mark.parametrize("filename", ["a", "new/b", "new2/new3/c"])
 def test_simple(
     lock_type: type[BaseFileLock],
     path_type: type[str] | type[Path],
+    filename: str,
     tmp_path: Path,
     caplog: pytest.LogCaptureFixture,
 ) -> None:
     caplog.set_level(logging.DEBUG)
 
     # test lock creation by passing a `str`
-    lock_path = tmp_path / "a"
+    lock_path = tmp_path / filename
     lock = lock_type(path_type(lock_path))
     with lock as locked:
         assert lock.is_locked
@@ -113,7 +106,6 @@ def test_ro_file(lock_type: type[BaseFileLock], tmp_file_ro: Path) -> None:
 @pytest.mark.parametrize(
     ("expected_error", "match", "bad_lock_file"),
     [
-        pytest.param(FileNotFoundError, "No such file or directory:", "a/b", id="non_existent_directory"),
         pytest.param(FileNotFoundError, "No such file or directory:", "", id="blank_filename"),
         pytest.param(ValueError, "embedded null (byte|character)", "\0", id="null_byte"),
         # Should be PermissionError on Windows