Added more tests for strip_tags utility

Refs #19237.

tests/utils_tests/html.py

@@ -1,8 +1,12 @@
 from __future__ import unicode_literals
 
+from datetime import datetime
+import os
 import unittest
 
 from django.utils import html
+from django.utils._os import upath
+
 
 class TestUtilsHtml(unittest.TestCase):
 
@@ -73,6 +77,18 @@ class TestUtilsHtml(unittest.TestCase):
         for value, output in items:
             self.check_output(f, value, output)
 
+        # Test with more lengthy content (also catching performance regressions)
+        for filename in ('strip_tags1.html', 'strip_tags2.txt'):
+            path = os.path.join(os.path.dirname(upath(__file__)), 'files', filename)
+            with open(path, 'r') as fp:
+                start = datetime.now()
+                stripped = html.strip_tags(fp.read())
+                elapsed = datetime.now() - start
+            self.assertEqual(elapsed.seconds, 0)
+            self.assertLess(elapsed.microseconds, 100000)
+            self.assertIn("Please try again.", stripped)
+            self.assertNotIn('<', stripped)
+
     def test_strip_spaces_between_tags(self):
         f = html.strip_spaces_between_tags
         # Strings that should come out untouched.