1 files changed, 31 insertions, 0 deletions
diff --git a/tests/test_using_api.py b/tests/test_using_api.py
new file mode 100644
index 00000000..0af12441
--- /dev/null
+++ b/tests/test_using_api.py
@@ -0,0 +1,31 @@
+import unittest
+from pygments.lexer import using, bygroups, this, RegexLexer
+from pygments.token import String, Text, Keyword
+
+class TestLexer(RegexLexer):
+    tokens = {
+        'root': [
+            (r'#.*', using(this, state='invalid')),
+            (r'(")(.+?)(")', bygroups(String, using(this, state='string'), String)),
+            (r'[^"]+', Text),
+        ],
+        'string': [
+            (r'.+', Keyword),
+        ],
+    }
+
+class UsingStateTest(unittest.TestCase):
+    def test_basic(self):
+        expected = [(Text, 'a'), (String, '"'), (Keyword, 'bcd'),
+                    (String, '"'), (Text, 'e\n')]
+        t = list(TestLexer().get_tokens('a"bcd"e'))
+        self.assertEquals(t, expected)
+    def test_error(self):
+        def gen():
+            x = list(TestLexer().get_tokens('#a'))
+        #XXX: should probably raise a more specific exception if the state
+        #     doesn't exist.
+        self.assertRaises(Exception, gen)
+
+if __name__ == "__main__":
+    unittest.main()