anchor.diff:    bool shouldBeMigrated(DriverBasedAnalysisContext context, String path) =>
         cli._test.overrideShouldBeMigrated?.call(path) ??
         super.shouldBeMigrated(context, path);
  +
  +  /// Sorts the paths in [paths] for repeatability of migration tests.
  +  Set<String> _sortPaths(Set<String> paths) {
  +    var pathList = paths.toList();
  +    pathList.sort();
  +    return pathList.toSet();
  +  }
   }
   
   abstract class _MigrationCliTestBase {
  
positive.code:     // But it should not mention foo.dart or bar.dart, which are migrated
      expect(output, isNot(contains('package:foo/foo.dart')));
      expect(output, isNot(contains('package:bar/bar.dart')));
    }
  
    test_lifecycle_no_preview() async {
  
negative.code: 
    @override
    Set<String> computePathsToProcess(DriverBasedAnalysisContext context) =>
        cli._test.overridePathsToProcess ??
        _sortPaths(super.computePathsToProcess(context));
  
    @override
    NonNullableFix createNonNullableFix(
  