We upgraded Babel from 5 to 6 in ThinkJS 2.1. Because Babel 6 is a refactored version that all functions build by plug-ins, and many modules of it relied on different plug-ins. That will leads to some problems:
The best solution is to upgrade your npm to version 3. Use following command to upgrade:
npm install -g npm@3The default compile parameters of Babel 6 are:
{
  presets: ['es2015-loose', 'stage-1'],
  plugins: ['transform-runtime']
}If the configure here doesn't satisfy with your requirements,you can modify it in file www/development.js:
instance.compile({
  retainLines: true,
  log: true,
  presets: [], //appended presets list
  plugins: [] //appended plugins list
});At some point, before your deploy, you want to run npm run compile, this will actually call the compile script in package.json. So, if you have set presets or plugins list, then you should change the compile command accordingly.