1 files changed, 52 insertions, 0 deletions
diff --git a/tests/test_regexopt.py b/tests/test_regexopt.py
new file mode 100644
index 00000000..f62a57ef
--- /dev/null
+++ b/tests/test_regexopt.py
@@ -0,0 +1,52 @@
+# -*- coding: utf-8 -*-
+"""
+    Tests for pygments.regexopt
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+    :copyright: Copyright 2006-2014 by the Pygments team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+
+import re
+import random
+import unittest
+import itertools
+
+from pygments.regexopt import regex_opt
+
+ALPHABET = ['a', 'b', 'c', 'd', 'e']
+
+try:
+    from itertools import combinations_with_replacement
+    N_TRIES = 15
+except ImportError:
+    # Python 2.6
+    def combinations_with_replacement(iterable, r):
+        pool = tuple(iterable)
+        n = len(pool)
+        for indices in itertools.product(range(n), repeat=r):
+            if sorted(indices) == list(indices):
+                yield tuple(pool[i] for i in indices)
+    N_TRIES = 9
+
+
+class RegexOptTestCase(unittest.TestCase):
+
+    def generate_keywordlist(self, length):
+        return [''.join(p) for p in
+                combinations_with_replacement(ALPHABET, length)]
+
+    def test_randomly(self):
+        # generate a list of all possible keywords of a certain length using
+        # a restricted alphabet, then choose some to match and make sure only
+        # those do
+        for n in range(3, N_TRIES):
+            kwlist = self.generate_keywordlist(n)
+            to_match = random.sample(kwlist,
+                                     random.randint(1, len(kwlist) - 1))
+            no_match = set(kwlist) - set(to_match)
+            rex = re.compile(regex_opt(to_match))
+            for w in to_match:
+                self.assertTrue(rex.match(w))
+            for w in no_match:
+                self.assertFalse(rex.match(w))