[LNT] Python 3 support: specify how to sort dict

Summary:
To be able to compare 2 lists of dictionaries, test
server/ui/test_roundtrip.py calls sorted on those list so that they are
comparable. However no comparison function is given so it fails on
Python 3 because dictionary are not comparable. This commit adds a key
parameter to sort on the name key of these dictionaries.

Reviewers: cmatthews, hubert.reinterpretcast, kristof.beyls, leandron, PrzemekWirkus

Reviewed By: cmatthews

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D68920

Author: Thomas Preud'homme

tests/server/ui/test_roundtrip.py

@@ -94,8 +94,10 @@ def _compare_results(self, after_submit_run, before_submit_run):
         for k in ['machine', 'run']:
             self.assertEqual(before_submit_run[k], after_submit_run[k])
         # The order of the tests might have changed, so sort before they are compared.
-        before_submit_tests = sorted(before_submit_run['tests'])
-        after_submit_tests = sorted(after_submit_run['tests'])
+        before_submit_tests = sorted(before_submit_run['tests'],
+                                     key=lambda test: test['id'])
+        after_submit_tests = sorted(after_submit_run['tests'],
+                                    key=lambda test: test['id'])
         for i, _ in enumerate(before_submit_tests):
             before_submit_tests[i]['run_id'] = 1234
             after_submit_tests[i]['run_id'] = 1234