Add tests relevant to descriptions for arguments.py

tests/test_arguments.py

@@ -47,6 +47,27 @@ def test_basic_check_correct():
         (["--json", "--nowelcome", "CheckCommits"]),
         (["--nowelcome", "CheckCommits"]),
         (["--checkerdir", "./gator/checks", "CheckCommits"]),
+        (["--description", "Are there 12 commits?", "CheckCommits"]),
+        (
+            [
+                "--checkerdir",
+                "./gator/checks",
+                "--description",
+                "Are there 18 commits?",
+                "CheckCommits",
+            ]
+        ),
+        (
+            [
+                "--json",
+                "--nowelcome",
+                "--checkerdir",
+                "./gator/checks",
+                "--description",
+                "Are there 18 commits?",
+                "CheckCommits",
+            ]
+        ),
     ],
 )
 def test_optional_commandline_arguments_can_verify(commandline_arguments):
@@ -80,6 +101,42 @@ def test_checkerdir_is_not_valid_arguments_verify(tmpdir):
     assert args_verified is False
 
 
+def test_description_is_valid_arguments_verify():
+    """Check that command-line argument with valid string verifies."""
+    commandline_arguments = [
+        "--description",
+        "Do you have fake things?",
+        "check_FakeMessages",
+    ]
+    gg_arguments, remaining_arguments = arguments.parse(commandline_arguments)
+    args_verified = arguments.verify(gg_arguments)
+    assert args_verified is True
+
+
+def test_description_not_specified_is_not_valid_arguments_verify(capsys):
+    """Check that command-line argument without valid string verifies."""
+    commandline_arguments = ["--description", "--json", "check_FakeMessages"]
+    with pytest.raises(SystemExit):
+        gg_arguments, remaining_arguments = arguments.parse(commandline_arguments)
+        _ = arguments.verify(gg_arguments)
+    captured = capsys.readouterr()
+    assert "--description: expected one argument" in captured.err
+
+
+@pytest.mark.parametrize(
+    "commandline_arguments",
+    [
+        (["--description", "", "CheckCommits"]),
+        (["--description", 'Run the "check" check', "CheckCommits"]),
+    ],
+)
+def test_description_is_not_valid_arguments_verify(commandline_arguments):
+    """Check that command-line argument without valid string verifies."""
+    gg_arguments, remaining_arguments = arguments.parse(commandline_arguments)
+    args_verified = arguments.verify(gg_arguments)
+    assert args_verified is False
+
+
 def test_help_produces_output(capsys):
     """Ensure that when given a request for help, it is produced correctly."""
     with pytest.raises(SystemExit):