anchor.diff:        }
         try {
           var expectedCode = expectFile.readAsStringSync();
  -        var actualCode =
  -            fileContentCache[filePath] ?? originalFile.readAsStringSync();
  +        var actualIsOriginal = !fileContentCache.containsKey(filePath);
  +        var actualCode = actualIsOriginal
  +            ? originalFile.readAsStringSync()
  +            : fileContentCache[filePath];
           // Use a whitespace insensitive comparison.
           if (_compressWhitespace(actualCode) !=
               _compressWhitespace(expectedCode)) {
             result.failCount++;
             // TODO(brianwilkerson) Do a better job of displaying the differences.
             //  It's very hard to see the diff with large files.
  -          _reportFailure(filePath, actualCode, expectedCode);
  +          _reportFailure(
  +            filePath,
  +            actualCode,
  +            expectedCode,
  +            actualIsOriginal: actualIsOriginal,
  +          );
           } else {
             result.passCount++;
           }
  
positive.code: 
  import 'package:analysis_server_client/protocol.dart' hide AnalysisError;
  import 'package:intl/intl.dart';
  import 'package:path/path.dart' as path;
  
  import '../analysis_server.dart';
  
negative.code: 
    /// Report that the [actualCode] produced by applying fixes to the content of
    /// [filePath] did not match the [expectedCode].
    void _reportFailure(String filePath, String actualCode, String expectedCode,
        {@required bool actualIsOriginal}) {
      log.stdout('Failed when applying fixes to $filePath');
      log.stdout('Expected:');
      log.stdout(expectedCode);
      log.stdout('');
      if (actualIsOriginal) {
        log.stdout('Actual (original code was unchanged):');
      } else {
        log.stdout('Actual:');
      }
      log.stdout(actualCode);
    }
  
  