报错：`Path must be a string. Received null` 解决方法：用yarn安装所有依赖后，再用npm 重新安装phantomjs-prebuilt，运行yarn test 或者 npm run test就可以了 参考：[https://github.com/karma-runner/karma-phantomjs-launcher/issues/120](https://github.com/karma-runner/karma-phantomjs-launcher/issues/120)
报错：
Path must be a string. Received null解决方法：用yarn安装所有依赖后，再用npm 重新安装phantomjs-prebuilt，运行yarn test 或者 npm run test就可以了
参考：karma-runner/karma-phantomjs-launcher#120