Working with files

Files can be uploaded to and downloaded from test environment instances as artifacts.

File class

The File class represents a file. Its constructor accepts three arguments:

• src (str): File path to load file from.
• dest (str): File path for where to dump file.
• overwrite (bool): Overwrite the file if it already exists at dest. Defaults to False.

File versus Dir

When the File class's load method is invoked, an exception will be raised if src is determined to be a directory and not a file. This exception is raised because cleantest handles files differently than directories when dumping out to dest. If you are working with directories, not files, you should use the Dir class instead.

Supported hooks

The File class's behavior changes depending on the hook it is used with. Here is a list of hooks that support File and how File behaves when accessed by them:

StartEnvHook

src is loaded from local system and dest is the location to dump the file inside the test environment instance.

StopEnvHook

src is loaded from the test environment instance and dest is the location to dump the file on the local system.

Example usage

#!/usr/bin/env python3

"""Example usage of File class."""

import os
import pathlib

from cleantest.control import Configure
from cleantest.control.hooks import StartEnvHook, StopEnvHook
from cleantest.data import File
from cleantest.provider import lxd


@lxd(image="ubuntu-jammy-amd64", preserve=False)
def work_on_artifacts():
    import pathlib
    import sys

    print(pathlib.Path("/root/greeting.txt").is_file(), file=sys.stdout)

    pathlib.Path("/root/dump.txt").write_text("Dumped like a sack of rocks")


def test_upload_download(clean_slate) -> None:
    root = pathlib.Path(os.path.dirname(os.path.realpath(__file__)))
    config = Configure("lxd")
    start_hook = StartEnvHook(
        name="upload_artifact",
        upload=[
            File(root / "greeting.txt", "/root/greeting.txt"),
        ],
    )
    stop_hook = StopEnvHook(
        name="download_artifact",
        download=[
            File("/root/dump.txt", root / "dump.txt", overwrite=True,),
        ],
    )
    config.register_hook(start_hook, stop_hook)
    for name, result in work_on_artifacts():
        assert (root / "dump.txt").is_file() is True
    (root / "dump.txt").unlink(missing_ok=True)