import scss in js
Firstly, sassLoader and postcss are not valid webpack config attributes https://webpack.js.org/configuration
The way you would typically go about it is to add the .scss file to your entry
entry: {
app: './src/app.js',
styles: './pathtoyourstyles/style.scss'
},
and then add the appropriate loaders.
loaders: [
{
test: /\.scss$/,
loaders: ["style-loader", "css-loader", "sass-loader"]
}
]