anchor.diff:  
       computeResult(script, TOKEN_STREAM, matcher: isScanDartTask);
       expect(outputs[LINE_INFO], isNotNull);
  -    expect(outputs[SCAN_ERRORS], isEmpty);
  +    if (fe.Scanner.useFasta) {
  +      // Missing closing brace error is reported by Fasta scanner.
  +      expect(outputs[SCAN_ERRORS], hasLength(1));
  +    } else {
  +      expect(outputs[SCAN_ERRORS], isEmpty);
  +    }
       Token tokenStream = outputs[TOKEN_STREAM];
       expect(tokenStream, isNotNull);
       expect(tokenStream.lexeme, 'void');
  
positive.code:     expect(ignoreInfo.hasIgnores, isFalse);
    }
  
    test_perform_noErrors() {
      _performScanTask('class A {}');
      expect(outputs, hasLength(4));
  
negative.code:     _assertHasCore(outputs[IMPORTED_LIBRARIES], 2);
      expect(outputs[INCLUDED_PARTS], hasLength(1));
      expect(outputs[LIBRARY_SPECIFIC_UNITS], hasLength(2));
      if (fe.Scanner.useFasta) {
        // Missing closing brace error is reported by the Fasta scanner.
        expect(outputs[PARSE_ERRORS], hasLength(0));
      } else {
        expect(outputs[PARSE_ERRORS], hasLength(1));
      }
      expect(outputs[PARSED_UNIT], isNotNull);
      expect(outputs[REFERENCED_SOURCES], hasLength(5));
      expect(outputs[SOURCE_KIND], SourceKind.LIBRARY);
  