more tests

pytube/helpers.py

@@ -26,21 +26,21 @@ def regex_search(pattern, string, groups=False, group=None, flags=0):
     """
     regex = re.compile(pattern, flags)
     results = regex.search(string)
-    logger.debug(
-        'finished regex search: %s',
-        pprint.pformat(
-            {
-                'pattern': pattern,
-                'results': results.group(0),
-            }, indent=2,
-        ),
-    )
     if not results:
         raise RegexMatchError(
             'regex pattern ({pattern}) had zero matches'
             .format(pattern=pattern),
         )
     else:
+        logger.debug(
+            'finished regex search: %s',
+            pprint.pformat(
+                {
+                    'pattern': pattern,
+                    'results': results.group(0),
+                }, indent=2,
+            ),
+        )
         if groups:
             return results.groups()
         elif group is not None:

tests/test_helpers.py

@@ -0,0 +1,21 @@
+# -*- coding: utf-8 -*-
+import pytest
+
+from pytube import helpers
+from pytube.exceptions import RegexMatchError
+
+
+def test_regex_search_no_match():
+    with pytest.raises(RegexMatchError):
+        helpers.regex_search('^a$', '', groups=True)
+
+
+def test_regex_search():
+    # TODO(nficano): should check isinstance
+    assert helpers.regex_search('^a$', 'a') is not None
+
+
+def test_safe_filename():
+    """Unsafe characters get stripped from generated filename"""
+    assert helpers.safe_filename('abc1245$$') == 'abc1245'
+    assert helpers.safe_filename('abc##') == 'abc'