feat[cli]: Use nice cli

tests/test_cli.py

@@ -96,16 +96,46 @@ def test_main_returns_failure_for_invalid_config(monkeypatch):
 
     monkeypatch.setattr(cli, "read_toml_config", fake_read_toml_config)
 
-    assert cli.main(["bad.toml"]) == 1
+    assert cli.main(["--config", "bad.toml"]) == 1
 
 
-def test_main_uses_config_path(monkeypatch, tmp_path):
+def test_main_uses_config_option(monkeypatch, tmp_path):
     config = make_config(tmp_path)
     calls = []
+    paths = []
 
-    monkeypatch.setattr(cli, "read_toml_config", lambda path: config)
+    def fake_read_toml_config(path):
+        paths.append(path)
+        return config
+
+    monkeypatch.setattr(cli, "read_toml_config", fake_read_toml_config)
     monkeypatch.setattr(cli, "setup_logging", lambda logging_config: None)
     monkeypatch.setattr(cli, "run", lambda config: calls.append(config) or 0)
 
-    assert cli.main(["config.toml"]) == 0
+    assert cli.main(["--config", "config.toml"]) == 0
+    assert paths == ["config.toml"]
     assert calls == [config]
+
+
+def test_main_requires_config_option(capsys):
+    try:
+        cli.main([])
+    except SystemExit as err:
+        assert err.code == 2
+    else:
+        raise AssertionError("expected SystemExit")
+
+    assert "error:" in capsys.readouterr().err
+
+
+def test_main_rejects_positional_config(capsys):
+    try:
+        cli.main(["config.toml"])
+    except SystemExit as err:
+        assert err.code == 2
+    else:
+        raise AssertionError("expected SystemExit")
+
+    stderr = capsys.readouterr().err
+    assert "error:" in stderr
+    assert "--config" in stderr