Add unit tests to ensure code basic functionalities

.gitlab-ci.yml

@@ -27,6 +27,7 @@ linting:
   stage: test
   script:
   - flake8 --ignore=F401,F811,W504 bline
+  - flake8 tests
 
 python3.6:
   image: python:3.6

tests/test_bline.py

@@ -6,19 +6,18 @@
 import unittest
 import sys
 
-try:
-    import bline
-except ImportError:
-     pass
+from unittest.mock import patch
+
 
 class TestBline(unittest.TestCase):
     """Tests for `bline` package."""
 
-    def setUp(self):
-        """Set up test fixtures, if any."""
-
-    def tearDown(self):
-        """Tear down test fixtures, if any."""
-
     def test_import(self):
-        self.assertTrue('bline' in sys.modules, "Bline import failed!")
+        """Test bline import"""
+        with patch.object(sys, 'argv', ['bline']):
+            with self.assertRaises(SystemExit):
+                try:
+                    import bline.bline as bp
+                    self.assertTrue(bp.PROG_NAME, 'BLINE')
+                except ImportError:
+                    self.fail('Failed to import bline!')

tox.ini

@@ -5,6 +5,7 @@ envlist = py36, py37, py38, flake8
 basepython = python
 deps = flake8
 commands = flake8 --ignore=F401,F811,W504 bline
+           flake8 tests
 
 [testenv]
 commands = python -m unittest