diff -r 000000000000 -r 6474c204b198 testing/mozbase/manifestdestiny/tests/test_expressionparser.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/testing/mozbase/manifestdestiny/tests/test_expressionparser.py	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,95 @@
+#!/usr/bin/env python
+
+import unittest
+from manifestparser import parse
+
+class ExpressionParserTest(unittest.TestCase):
+    """Test the conditional expression parser."""
+
+    def test_basic(self):
+
+        self.assertEqual(parse("1"), 1)
+        self.assertEqual(parse("100"), 100)
+        self.assertEqual(parse("true"), True)
+        self.assertEqual(parse("false"), False)
+        self.assertEqual('', parse('""'))
+        self.assertEqual(parse('"foo bar"'), 'foo bar')
+        self.assertEqual(parse("'foo bar'"), 'foo bar')
+        self.assertEqual(parse("foo", foo=1), 1)
+        self.assertEqual(parse("bar", bar=True), True)
+        self.assertEqual(parse("abc123", abc123="xyz"), 'xyz')
+
+    def test_equality(self):
+
+        self.assertTrue(parse("true == true"))
+        self.assertTrue(parse("false == false"))
+        self.assertTrue(parse("1 == 1"))
+        self.assertTrue(parse("100 == 100"))
+        self.assertTrue(parse('"some text" == "some text"'))
+        self.assertTrue(parse("true != false"))
+        self.assertTrue(parse("1 != 2"))
+        self.assertTrue(parse('"text" != "other text"'))
+        self.assertTrue(parse("foo == true", foo=True))
+        self.assertTrue(parse("foo == 1", foo=1))
+        self.assertTrue(parse('foo == "bar"', foo='bar'))
+        self.assertTrue(parse("foo == bar", foo=True, bar=True))
+        self.assertTrue(parse("true == foo", foo=True))
+        self.assertTrue(parse("foo != true", foo=False))
+        self.assertTrue(parse("foo != 2", foo=1))
+        self.assertTrue(parse('foo != "bar"', foo='abc'))
+        self.assertTrue(parse("foo != bar", foo=True, bar=False))
+        self.assertTrue(parse("true != foo", foo=False))
+        self.assertTrue(parse("!false"))
+
+    def test_conjunctures(self):
+        self.assertTrue(parse("true && true"))
+        self.assertTrue(parse("true || false"))
+        self.assertFalse(parse("false || false"))
+        self.assertFalse(parse("true && false"))
+        self.assertTrue(parse("true || false && false"))
+
+    def test_parentheses(self):
+        self.assertTrue(parse("(true)"))
+        self.assertEqual(parse("(10)"), 10)
+        self.assertEqual(parse('("foo")'), 'foo')
+        self.assertEqual(parse("(foo)", foo=1), 1)
+        self.assertTrue(parse("(true == true)"), True)
+        self.assertTrue(parse("(true != false)"))
+        self.assertTrue(parse("(true && true)"))
+        self.assertTrue(parse("(true || false)"))
+        self.assertTrue(parse("(true && true || false)"))
+        self.assertFalse(parse("(true || false) && false"))
+        self.assertTrue(parse("(true || false) && true"))
+        self.assertTrue(parse("true && (true || false)"))
+        self.assertTrue(parse("true && (true || false)"))
+        self.assertTrue(parse("(true && false) || (true && (true || false))"))
+
+
+    def test_comments(self):
+        # comments in expressions work accidentally, via an implementation
+        # detail - the '#' character doesn't match any of the regular
+        # expressions we specify as tokens, and thus are ignored.
+        # However, having explicit tests for them means that should the
+        # implementation ever change, comments continue to work, even if that
+        # means a new implementation must handle them explicitly.
+        self.assertTrue(parse("true == true # it does!"))
+        self.assertTrue(parse("false == false # it does"))
+        self.assertTrue(parse("false != true # it doesnt"))
+        self.assertTrue(parse('"string with #" == "string with #" # really, it does'))
+        self.assertTrue(parse('"string with #" != "string with # but not the same" # no match!'))
+
+    def test_not(self):
+        """
+        Test the ! operator.
+        """
+        self.assertTrue(parse("!false"))
+        self.assertTrue(parse("!(false)"))
+        self.assertFalse(parse("!true"))
+        self.assertFalse(parse("!(true)"))
+        self.assertTrue(parse("!true || true)"))
+        self.assertTrue(parse("true || !true)"))
+        self.assertFalse(parse("!true && true"))
+        self.assertFalse(parse("true && !true"))
+
+if __name__ == '__main__':
+    unittest.main()