anchor.diff:  
         // Analyze b.dart (part) and then a.dart (its library).
         // No errors should be reported - the part should know its library.
  -      await _doDrive(bDart, uri: bUri, additionalArgs: ['$aUri|$aDart']);
  +      await _doDrive(bDart, fileUri: bUri, additionalArgs: ['$aUri|$aDart']);
         expect(errorSink, isEmpty);
       });
     }
  
positive.code:     String options = emptyOptionsFile,
      List<String> args = const <String>[],
    }) async {
      options = _p(options);
  
      driver = Driver(isTesting: true);
      var cmd = <String>[];
  
negative.code:     args.add('--build-summary-output=${pkg.sum}');
      args.add('--summary-deps-output=${pkg.dep}');
  
      await _doDrive(pkg.path, fileUri: pkg.uri, additionalArgs: args);
      expect(exitCode, 0);
  
      return pkg;
  