[IO-1332][internal] E2E Test harness

e2e_tests/e2e_test.md

@@ -0,0 +1,5 @@
+# End to end tests module
+
+This module is setup in `pytest.ini` to _not run_.  If you want to run the E2E tests,
+you will need to run `pytest e2e_tests` rather than `pytest`.
+

e2e_tests/helpers.py

@@ -0,0 +1,42 @@
+from subprocess import run
+from typing import Optional, Tuple
+
+from darwin.exceptions import DarwinException
+
+
+def run_cli_command(command: str, working_directory: Optional[str] = None) -> Tuple[int, str, str]:
+    """
+    Run a CLI command and return the return code, stdout, and stderr.
+
+    Parameters
+    ----------
+    command : str
+        The command to run.
+    working_directory : str, optional
+        The working directory to run the command in.
+
+    Returns
+    -------
+    Tuple[int, str, str]
+        The return code, stdout, and stderr.
+    """
+
+    # Do ot allow directory traversal
+    if ".." in command or (working_directory and ".." in working_directory):
+        raise DarwinException("Cannot pass directory traversal to 'run_cli_command'.")
+
+    if working_directory:
+        result = run(
+            command,
+            cwd=working_directory,
+            capture_output=True,
+            shell=True,
+        )
+    else:
+        result = run(
+            command,
+            capture_output=True,
+            shell=True,
+        )
+
+    return result.returncode, result.stdout.decode("utf-8"), result.stderr.decode("utf-8")

e2e_tests/test_example.py

@@ -0,0 +1,9 @@
+import pytest
+
+
+def test_example_test_does_nothing() -> None:
+    assert True
+
+
+if __name__ == "__main__":
+    pytest.main()

pytest.ini

@@ -0,0 +1,2 @@
+[pytest]
+addopts = --ignore=e2e_tests

tests/e2e_test_internals/test_run_cli_command.py

@@ -0,0 +1,58 @@
+from collections import namedtuple
+from unittest import mock
+
+import pytest
+
+from darwin.exceptions import DarwinException
+from e2e_tests.helpers import run_cli_command
+
+
+def test_does_not_allow_directory_traversal() -> None:
+    with pytest.raises(DarwinException) as excinfo:
+        run_cli_command("darwin --help; ls ..")
+
+        assert excinfo.value == "Cannot pass directory traversal to 'run_cli_command'."
+
+    with pytest.raises(DarwinException) as excinfo:
+        run_cli_command("darwin --help", working_directory="/usr/bin/../")
+        assert excinfo.value == "Cannot pass directory traversal to 'run_cli_command'."
+
+
+@mock.patch("e2e_tests.helpers.run")
+def test_passes_working_directory_to_run_cli_command(mock_subprocess_run: mock.Mock) -> None:
+    mock_subprocess_run.reset_mock()
+    run_cli_command("darwin --help", "/usr/bin")
+
+    mock_subprocess_run.assert_called_once()
+    assert mock_subprocess_run.call_args[0][0] == "darwin --help"
+    assert mock_subprocess_run.call_args[1]["cwd"] == "/usr/bin"
+
+
+@mock.patch("e2e_tests.helpers.run")
+def test_passes_back_returncode_stdout_and_stderr(mock_subprocess_run: mock.Mock) -> None:
+    CompletedProcess = namedtuple("CompletedProcess", ["returncode", "stdout", "stderr"])
+    mocked_output = CompletedProcess(returncode=137, stdout=b"stdout", stderr=b"stderr")
+
+    mock_subprocess_run.return_value = mocked_output
+
+    return_code, std_out, std_err = run_cli_command("darwin --help", "/usr/bin")
+
+    mock_subprocess_run.assert_called_once()
+
+    assert return_code == 137
+    assert std_out == "stdout"
+    assert std_err == "stderr"
+
+
+@mock.patch("e2e_tests.helpers.run")
+def test_does_not_pass_working_directory_to_run_cli_command(mock_subprocess_run: mock.Mock) -> None:
+    mock_subprocess_run.reset_mock()
+    run_cli_command("darwin --help")
+
+    mock_subprocess_run.assert_called_once()
+    assert mock_subprocess_run.call_args[0][0] == "darwin --help"
+    assert "cwd" not in mock_subprocess_run.call_args[1]
+
+
+if __name__ == "__main__":
+    pytest.main()