tests/hooks/test_subprocess.py

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import unittest
from pathlib import Path
from subprocess import PIPE, STDOUT
from tempfile import TemporaryDirectory
from unittest import mock

from parameterized import parameterized

from airflow.hooks.subprocess import SubprocessHook

OS_ENV_KEY = 'SUBPROCESS_ENV_TEST'
OS_ENV_VAL = 'this-is-from-os-environ'


class TestSubprocessHook(unittest.TestCase):
    @parameterized.expand(
        [
            ('with env', {'ABC': '123', 'AAA': '456'}, {'ABC': '123', 'AAA': '456', OS_ENV_KEY: ''}),
            ('empty env', {}, {OS_ENV_KEY: ''}),
            ('no env', None, {OS_ENV_KEY: OS_ENV_VAL}),
        ]
    )
    def test_env(self, name, env, expected):
        """
        Test that env variables are exported correctly to the command environment.
        When ``env`` is ``None``, ``os.environ`` should be passed to ``Popen``.
        Otherwise, the variables in ``env`` should be available, and ``os.environ`` should not.
        """
        hook = SubprocessHook()

        def build_cmd(keys, filename):
            """
            Produce bash command to echo env vars into filename.
            Will always echo the special test var named ``OS_ENV_KEY`` into the file to test whether
            ``os.environ`` is passed or not.
            """
            return '\n'.join(f"echo {k}=${k}>> {filename}" for k in [*keys, OS_ENV_KEY])

        with TemporaryDirectory() as tmp_dir, mock.patch.dict('os.environ', {OS_ENV_KEY: OS_ENV_VAL}):
            tmp_file = Path(tmp_dir, 'test.txt')
            command = build_cmd(env and env.keys() or [], tmp_file.as_posix())
            hook.run_command(command=['bash', '-c', command], env=env)
            actual = dict([x.split('=') for x in tmp_file.read_text().splitlines()])
            assert actual == expected

    @parameterized.expand(
        [
            ('test-val', 'test-val'),
            ('test-val\ntest-val\n', ''),
            ('test-val\ntest-val', 'test-val'),
            ('', ''),
        ]
    )
    def test_return_value(self, val, expected):
        hook = SubprocessHook()
        result = hook.run_command(command=['bash', '-c', f'echo "{val}"'])
        assert result.output == expected

    @mock.patch.dict('os.environ', clear=True)
    @mock.patch(
        "airflow.hooks.subprocess.TemporaryDirectory",
        **{'return_value.__enter__.return_value': '/tmp/airflowtmpcatcat'},  # type: ignore
    )
    @mock.patch(
        "airflow.hooks.subprocess.Popen",
        **{  # type: ignore
            'return_value.stdout.readline.side_effect': [b'BAR', b'BAZ'],
            'return_value.returncode': 0,
        },
    )
    def test_should_exec_subprocess(self, mock_popen, mock_temporary_directory):
        hook = SubprocessHook()
        hook.run_command(command=['bash', '-c', 'echo "stdout"'])

        mock_popen.assert_called_once_with(
            ['bash', '-c', 'echo "stdout"'],
            cwd='/tmp/airflowtmpcatcat',
            env={},
            preexec_fn=mock.ANY,
            stderr=STDOUT,
            stdout=PIPE,
        )