根据老师说的写了代码 但是在打包过程中有warning：

The 'mode' option has not been set. Set 'mode' option to 'development' or 'production' to enable

defaults for this environment.

并且打包出来的app.bundle.js只有如下内容

!function(e){var n={};function r(t){if(n[t])return n[t].exports;var o=n[t]={i:t,l:!1,exports:{}};return e[t].call(o.exports,o,o.exports,r),o.l=!0,o.exports}r.m=e,r.c=n,r.d=function(e,n,t){r.o(e,n)||Object.defineProperty(e,n,{configurable:!1,enumerable:!0,get:t})},r.r=function(e){Object.defineProperty(e,"__esModule",{value:!0})},r.n=function(e){var n=e&&e.__esModule?function(){return e.default}:function(){return e};return r.d(n,"a",n),n},r.o=function(e,n){return Object.prototype.hasOwnProperty.call(e,n)},r.p="",r(r.s=0)}([function(e,n){var r;r={name:"Tom",sex:"male"},console.log("miao~",r.name)}]);