add CLI test

Signed-off-by: Florian Brandes <florian.brandes@posteo.de>

tests/test_smtprd_ng.py

@@ -19,12 +19,14 @@
 Tests for smtprd_ng
 """
 # pylint: disable=protected-access
+# pylint: disable=unused-argument
 
 import configparser
 import email
 import email.message
 from pathlib import Path
 
+import pytest
 from M2Crypto import BIO, SMIME, X509
 
 from smtprd_ng import smtprd
@@ -134,3 +136,21 @@ def test_client_sign():
     p7, data = SMIME.smime_load_pkcs7_bio(buf)
     v = s.verify(p7, data)
     assert "Test to sign" in v.decode()
+
+
+def test_cli_no_config_file(capsys):
+    """Test whether config file parameter is supplied"""
+    test_args = ["--config", ""]
+    with pytest.raises(Exception) as e_info:
+        smtprd.main(test_args)
+    assert e_info.typename == "OSError"
+    assert str(e_info.value) == "No config file supplied"
+
+
+def test_cli_config_file_not_found(capsys):
+    """Test whether config file is found"""
+    test_args = ["--config", "doesnotexist.conf"]
+    with pytest.raises(Exception) as e_info:
+        smtprd.main(test_args)
+    assert e_info.typename == "OSError"
+    assert str(e_info.value) == "Config file not found: doesnotexist.conf"