anchor.diff:          _referencingNameTasks.isNotEmpty) {
         return AnalysisDriverPriority.interactive;
       }
  +    if (_errorsRequestedFiles.isNotEmpty) {
  +      return AnalysisDriverPriority.interactive;
  +    }
       if (_indexRequestedFiles.isNotEmpty) {
         return AnalysisDriverPriority.interactive;
       }
  
positive.code:       return null;
      }
  
      // Ask the analysis result without unit, so return cached errors.
      // If no cached analysis result, it will be computed.
      ResolvedUnitResult analysisResult = _computeAnalysisResult(path);
  
      // If not computed yet, because a part file without a known library,
      // we have to compute the full analysis result, with the unit.
      analysisResult ??= await getResult(path);
      if (analysisResult == null) {
        return null;
      }
  
      return ErrorsResultImpl(currentSession, path, analysisResult.uri,
          analysisResult.lineInfo, analysisResult.isPart, analysisResult.errors);
    }
  
    /// Return a [Future] that completes with the list of added files that
  
negative.code:       });
        return;
      }
  
      // Compute errors in a part.
      if (_errorsRequestedParts.isNotEmpty) {
        var path = _errorsRequestedParts.keys.first;
        var completers = _errorsRequestedParts.remove(path);
        var result = _computeErrors(path: path, asIsIfPartWithoutLibrary: true);
        completers.forEach((completer) {
          completer.complete(result);
        });
        return;
      }
    }
  
    /// Remove the file with the given [path] from the list of files to analyze.
  