test_decorators.py

"""Tests for our tests helpers.  8-}."""

import os
import sys

from cli_test_helpers import ArgvContext, EnvironContext, RandomDirectoryContext


def test_argv_context():
    """
    Does ArgvContext set new argvs and reset old ones correctly?
    """
    old = sys.argv
    new = ["Alice", "Bob", "Chris", "Daisy"]

    assert sys.argv == old

    with ArgvContext(*new):
        assert sys.argv == new, (
            "sys.argv wasn't correctly changed by the contextmanager"
        )

    assert sys.argv == old, "sys.argv wasn't correctly reset"


def test_environ_context():
    """
    Does EnvironContext set new environ values and reset old ones correctly?
    """
    old_environ = os.environ
    old_path = os.getenv("PATH")

    assert os.environ == old_environ
    assert os.getenv("PATH") is not None, "Invalid test setup"
    assert os.getenv("FOO") is None, "Invalid test setup"

    with EnvironContext(PATH=None, FOO="my foo value"):
        assert os.getenv("PATH") is None, (
            "os.environ[PATH] wasn't removed by the contextmanager"
        )
        assert os.getenv("FOO") == "my foo value", (
            "os.environ[FOO] wasn't set by the contextmanager"
        )

    assert os.environ == old_environ, "object os.environ was not restored"
    assert os.getenv("PATH") == old_path, "env var PATH was not restored"
    assert os.getenv("FOO") is None, "env var FOO was not cleared"


def test_random_directory_context():
    """
    In a directory context, are we effectively in a different location?
    """
    before_dir = os.getcwd()

    with RandomDirectoryContext() as random_dir:
        new_dir = os.getcwd()

        assert new_dir == random_dir, "Doesn't behave like TemporaryDirectory"
        assert new_dir != before_dir, "Context not in a different file system location"

    after_dir = os.getcwd()

    assert after_dir == before_dir, "Execution directory not restored to original"