loadProjectFile.js

function loadProjectFile() {
  var platform_ios;
  var projectFile;

  try {
    // try pre-5.0 cordova structure
    platform_ios = context.requireCordovaModule('cordova-lib/src/plugman/platforms')['ios'];
    projectFile = platform_ios.parseProjectFile(iosPlatformPath());
  } catch (e) {
      try {
          // let's try cordova 5.0 structure
          platform_ios = context.requireCordovaModule('cordova-lib/src/plugman/platforms/ios');
          projectFile = platform_ios.parseProjectFile(iosPlatformPath());
      } catch (e) {
          // Then cordova 7.0
          var project_files = context.requireCordovaModule('glob').sync(path.join(iosPlatformPath(), '*.xcodeproj', 'project.pbxproj'));

          if (project_files.length === 0) {
            throw new Error('does not appear to be an xcode project (no xcode project file)');
          }

          var pbxPath = project_files[0];

          var xcodeproj = context.requireCordovaModule('xcode').project(pbxPath);
          xcodeproj.parseSync();

          projectFile = {
              'xcode': xcodeproj,
              write: function () {
                  var fs = context.requireCordovaModule('fs');

              var frameworks_file = path.join(iosPlatformPath(), 'frameworks.json');
              var frameworks = {};
              try {
                  frameworks = context.requireCordovaModule(frameworks_file);
              } catch (e) { }

              fs.writeFileSync(pbxPath, xcodeproj.writeSync());
                  if (Object.keys(frameworks).length === 0){
                      // If there is no framework references remain in the project, just remove this file
                      context.requireCordovaModule('shelljs').rm('-rf', frameworks_file);
                      return;
                  }
                  fs.writeFileSync(frameworks_file, JSON.stringify(this.frameworks, null, 4));
              }
          };
      }
  }

  return projectFile;
}