我用webstorm照着写为什么会出现这些问题呢

WARNING in configuration

The 'mode' option has not been set, webpack will fallback to 'production' for this value. Set 'mode' option to 'development' or 'production' to enable defaults for each environment.

You can also set it to 'none' to disable any default behavior. Learn more: https://webpack.js.org/concepts/mode/

ERROR in ./src/index.js

Module not found: Error: Can't resolve './app,vue' in 'C:\Users\Administrator\Desktop\demo2\src'

 @ ./src/index.js 2:0-27 8:20-23

npm ERR! code ELIFECYCLE

npm ERR! errno 2

npm ERR! demo2@1.0.0 build: `webpack --config webpack.config.js`

npm ERR! Exit status 2

npm ERR! 

npm ERR! Failed at the demo2@1.0.0 build script.

npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:

npm ERR!     E:\node\node_cache\_logs\2019-05-14T04_06_28_724Z-debug.log

Process finished with exit code 2