1 files changed, 37 insertions, 0 deletions
diff --git a/layout/tools/reftest/selftest/test_python_manifest_parser.py b/layout/tools/reftest/selftest/test_python_manifest_parser.py
new file mode 100644
index 0000000000..5ec9ce324c
--- /dev/null
+++ b/layout/tools/reftest/selftest/test_python_manifest_parser.py
@@ -0,0 +1,37 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import mozunit
+import pytest
+
+
+@pytest.fixture
+def parse(normalize):
+    reftest = pytest.importorskip("reftest")
+
+    def inner(path):
+        mp = reftest.ReftestManifest()
+        mp.load(normalize(path))
+        return mp
+
+    return inner
+
+
+def test_parse_defaults(parse):
+    mp = parse("defaults.list")
+    assert len(mp.tests) == 4
+
+    for test in mp.tests:
+        if test["name"].startswith("foo"):
+            assert test["pref"] == "foo.bar,true"
+        else:
+            assert "pref" not in test
+
+    # invalid defaults
+    with pytest.raises(ValueError):
+        parse("invalid-defaults.list")
+
+
+if __name__ == "__main__":
+    mozunit.main()