Add lint check for `&DomRoot<T>`

`&DomRoot<T> is strictly less expressive than `&T`, so using it is
pointless.

2 files changed, 2 insertions, 1 deletions

diff --git a/python/tidy/servo_tidy_tests/rust_tidy.rs b/python/tidy/servo_tidy_tests/rust_tidy.rs
index 4b6c35b85cb..78b47a14401 100644
--- a/python/tidy/servo_tidy_tests/rust_tidy.rs
+++ b/python/tidy/servo_tidy_tests/rust_tidy.rs
@@ -38,7 +38,7 @@ impl test {
         }
     }
 
-    fn test_fun2(y : &String, z : &Vec<f32>, r: &Root<isize>) -> () {
+    fn test_fun2(y : &String, z : &Vec<f32>, r: &Root<isize>, s: &DomRoot<isize>) -> () {
         let x = true;
         x
             && x;
diff --git a/python/tidy/servo_tidy_tests/test_tidy.py b/python/tidy/servo_tidy_tests/test_tidy.py
index c13710057ab..441e9250c51 100644
--- a/python/tidy/servo_tidy_tests/test_tidy.py
+++ b/python/tidy/servo_tidy_tests/test_tidy.py
@@ -112,6 +112,7 @@ class CheckTidiness(unittest.TestCase):
         self.assertEqual('use &[T] instead of &Vec<T>', next(errors)[2])
         self.assertEqual('use &str instead of &String', next(errors)[2])
         self.assertEqual('use &T instead of &Root<T>', next(errors)[2])
+        self.assertEqual('use &T instead of &DomRoot<T>', next(errors)[2])
         self.assertEqual('encountered function signature with -> ()', next(errors)[2])
         self.assertEqual('operators should go at the end of the first line', next(errors)[2])
         self.assertNoMoreErrors(errors)