Webpack Output.library.type Var Is Undefined

I am learning WebPack with a shortcode. In the code, we are trying to calculate the cube and square. They will suppose to store in a variable as per the following webpack.config.js

Solution 1:

Finally, I got it working :-). I need to add the following line in my webpack.config.js

devServer: {
    injectClient:false
},

Following is the reference URL: https://github.com/webpack/webpack-dev-server/issues/2484

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