Auto merge of #11329 - c-rhodes:11320, r=jdm

Report use statements that use {} with only one entry

Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data:
- [X ] `./mach build -d` does not report any errors
- [X ] `./mach test-tidy --faster` does not report any errors
- [X ] These changes fix #11320  (github issue number if applicable).

Either:
- [X] There are tests for these changes OR
- [ ] These changes do not require tests because _____

Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process.

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="35" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/11329)
<!-- Reviewable:end -->

1 files changed, 1 insertions, 0 deletions

diff --git a/python/tidy/servo_tidy_tests/test_tidy.py b/python/tidy/servo_tidy_tests/test_tidy.py
index 55dbb4ce21a..47c3d7780a3 100644
--- a/python/tidy/servo_tidy_tests/test_tidy.py
+++ b/python/tidy/servo_tidy_tests/test_tidy.py
@@ -53,6 +53,7 @@ class CheckTidiness(unittest.TestCase):
         self.assertEqual('use statement spans multiple lines', errors.next()[2])
         self.assertEqual('missing space before }', errors.next()[2])
         self.assertTrue('use statement is not in alphabetical order' in errors.next()[2])
+        self.assertEqual('use statement contains braces for single import', errors.next()[2])
         self.assertEqual('encountered whitespace following a use statement', errors.next()[2])
         self.assertTrue('mod declaration is not in alphabetical order' in errors.next()[2])
         self.assertEqual('mod declaration spans multiple lines', errors.next()[2])