diff -r 000000000000 -r 6474c204b198 dom/bindings/parser/tests/test_date.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/bindings/parser/tests/test_date.py	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,15 @@
+def WebIDLTest(parser, harness):
+    parser.parse("""
+        interface WithDates {
+          attribute Date foo;
+          void bar(Date arg);
+          void baz(sequence<Date> arg);
+        };
+    """)
+
+    results = parser.finish()
+    harness.ok(results[0].members[0].type.isDate(), "Should have Date")
+    harness.ok(results[0].members[1].signatures()[0][1][0].type.isDate(),
+               "Should have Date argument")
+    harness.ok(not results[0].members[2].signatures()[0][1][0].type.isDate(),
+               "Should have non-Date argument")