checker: Added checkers for too more empty lines - fix: #4

requirements-dev.txt

@@ -4,4 +4,5 @@ pytest>=2.9.2
 pytest-cache>=1.0
 pytest-cov>=2.3.0
 pytest-flake8>=0.6
+pytest-mock>=1.6.0
 sphinx>=1.6,<1.7

tests/unit/test_checker_check_file.py

@@ -0,0 +1,25 @@
+import pytest
+
+from wscheck.checker import WhitespaceChecker
+from tests.unit.open_mock import patch_open_read
+
+
+@pytest.fixture
+def checker(mocker):
+    instance = WhitespaceChecker()
+    mocker.patch.object(instance, 'check_text', auto_spec=True)
+
+    return instance
+
+
+@pytest.mark.parametrize('file_path,file_content', [
+    ('/empty/file', ''),
+    ('/contains/anything', ' foo\t\r\nbar '),
+])
+def test_one_empty_line_is_good(checker, file_path, file_content):
+    mocked_files = {file_path: file_content}
+
+    with patch_open_read(mocked_files):
+        checker.check_file(file_path)
+
+    checker.check_text.assert_called_once_with(file_content, source_path=file_path)