docs: function onFile(file, encoding, done) {
  
      if (file.isNull()) {
        done(null, file);
  
        return;
      }
  
      if (file.isStream()) {
        this.emit('error', new PluginError(pluginName, 'Streaming is not supported'));
        done();
  
        return;
      }
  
      const localLintOptions = Object.assign({}, lintOptions, {
        code: file.contents.toString(),
        codeFilename: file.path
      });
  
      const lintPromise = lint(localLintOptions)
        .then(lintResult =>
          // Checking for the presence of sourceMap.mappings
          // in case sourcemaps are initialized, but still empty:
          file.sourceMap && file.sourceMap.mappings ?
            applySourcemap(lintResult, file.sourceMap) :
            lintResult
        )
        .then(lintResult => {
          if (lintOptions.fix && lintResult.output) {
            file.contents = Buffer.from(lintResult.output);
          }
  
          done(null, file);
  
          return lintResult;
        })
        .catch(error => {
          done(null, file);
  
          return Promise.reject(error);
        });
  
      lintPromiseList.push(lintPromise);
    }