Add test for path split and regression for old path behavior

Mock argv before calling ProspectorConfig in tests

.travis.yml

@@ -10,7 +10,7 @@ python:
   - "3.6-dev"
   - "3.7-dev"
 install:
-  - "pip install nose coverage coveralls"
+  - "pip install nose coverage coveralls mock"
   - "pip install git+https://github.com/landscapeio/pylint-plugin-utils.git@develop"
   - "pip install git+https://github.com/landscapeio/pylint-common.git@develop"
   - "pip install git+https://github.com/landscapeio/pylint-celery.git@develop"

tests/tools/pylint/test_pylint_tool.py

@@ -0,0 +1,31 @@
+# -*- coding: utf-8 -*-
+import os
+import sys
+from unittest import TestCase
+
+from prospector.config import ProspectorConfig
+from prospector.finder import find_python
+from prospector.tools.pylint import PylintTool
+
+if sys.version_info >= (3, 0):
+    from unittest.mock import patch
+else:
+    from mock import patch
+
+
+class TestPylintTool(TestCase):
+    def setUp(self):
+        with patch('sys.argv', ['']):
+            self.config = ProspectorConfig()
+        self.pylint_tool = PylintTool()
+
+    def test_absolute_path_is_computed_correctly(self):
+        root = os.path.join(os.path.dirname(__file__), 'testpath', 'test.py')
+        root_sep_split = root.split(os.path.sep)
+        root_os_split = os.path.split(root)
+        found_files = find_python([], [root], explicit_file_mode=True)
+        self.pylint_tool.configure(self.config, found_files)
+        self.assertNotEqual(self.pylint_tool._args,
+                            [os.path.join(*root_sep_split)])
+        self.assertEqual(self.pylint_tool._args,
+                         [os.path.join(*root_os_split)])

tox.ini

@@ -6,4 +6,5 @@ skip_missing_interpreters = true
 [testenv]
 deps =
     nose
+    py27: mock
 commands = nosetests tests