code: function getPageOriginFileExtnames(pageFileNotExt, buildManager) {
      let {files: allFiles, appType, buildConf, componentExtname} = buildManager;
  
      // handle native file
      let compFilesInfo = getCompFilesInfoByAppType(pageFileNotExt, {
          appType,
          wx2swan: buildConf.wx2swan,
          componentExtname,
          compileContext: buildManager.compileContext
      });
  
      let filesMap = {};
      let {componentType, missingMustFileExtnames, fileExtnameMap} = compFilesInfo;
  
      Object.keys(fileExtnameMap || {}).forEach(k => {
          let pageFile = allFiles.getByFullPath(fileExtnameMap[k]);
          if (!pageFile) {
              return;
          }
          filesMap[k] = pageFile;
      });
  
      // all must have js script except quick
      let scriptFile = filesMap.js;
      if (componentType && scriptFile) {
          scriptFile[componentType] = true;
      }
  
      let jsonFile = filesMap.json;
      if (jsonFile) {
          jsonFile.isComponentConfig = true;
          jsonFile.component = scriptFile;
      }
  
      return {
          missingMustFileExtnames,
          filesMap
      };
  }
docs: 根据类型 获取页面原生文件后缀名，以及相应的错误提示
  
  @param  {string} pageFileNotExt  page file no extname
  @param  {Object} buildManager      build
  @return {Object}                {missingMustFileExtnames, filesMap}
  {
  // 对应原生缺失的必要文件的后缀名
  missingMustFileExtnames,
  // 后缀名: 文件对象 {extname: fileObject}
  filesMap
  }