test(cli): ensure version flags bypass config creation

tests/test_littlepay.py

@@ -1,4 +1,5 @@
 from pathlib import Path
+import re
 import subprocess
 
 import pytest
@@ -50,3 +51,14 @@ def test_config(capfd):
     assert "Participants:" in capture.out
     assert "Active:" in capture.out
     assert res == RESULT_SUCCESS
+
+
+@pytest.mark.parametrize("version_flag", ["-v", "--version"])
+def test_version(capfd, version_flag):
+    res = subprocess.call(["littlepay", version_flag])
+    capture = capfd.readouterr()
+
+    assert "Creating config file:" not in capture.out
+    assert "Config:" not in capture.out
+    assert re.match(r"littlepay \d+\.\d+\.", capture.out)
+    assert res == RESULT_SUCCESS

tests/test_main.py

@@ -1,9 +1,12 @@
 from argparse import Namespace
 from pathlib import Path
+import re
+
 import pytest
 
 from littlepay.commands import RESULT_FAILURE, RESULT_SUCCESS
 from littlepay.config import CONFIG_TYPES, Config
+import littlepay.main
 from littlepay.main import main, __name__ as MODULE
 
 
@@ -268,3 +271,21 @@ def test_main_unrecognized(capfd):
     capture = capfd.readouterr()
     assert err.value.code != RESULT_SUCCESS
     assert "usage: littlepay" in capture.err
+
+
+@pytest.mark.parametrize("version_flag", ["-v", "--version"])
+def test_main_version_flag(version_flag, mocker, capfd, mock_commands_config):
+    # littlepay.main.Config (the class)
+    config_cls = mocker.patch.object(littlepay.main, "Config")
+    # littlepay.main.Config() (an instance)
+    config = config_cls.return_value
+
+    with pytest.raises(SystemExit) as err:
+        main(argv=[version_flag])
+    capture = capfd.readouterr()
+
+    assert err.value.code == RESULT_SUCCESS
+    assert re.match(r"littlepay \d+\.\d+\.", capture.out)
+    mock_commands_config.assert_not_called()
+    # there should have been no calls to any method on littlepay.main.Config()
+    assert len(config.mock_calls) == 0