I have a project, where I use webpack, react, sass. My project structure and webpack.config below. In project I need for purpose to import write @import 'styles/BigComp/index.sass' or import BigComp from './components/BigComp/Index.jsx', but I wanted to omit "index", to set webpack config in a way, that it can figure out, that if in the folder has file index.sass or Index.jsx, then webpack need to import it. In conclusion, I want to write import BigComp from './components/BigComp' to import ./components/BigComp/Index.jsx and write @import 'styles/BigComp' to import styles/BigComp/index.sass. I hope, I make myself clear.
// Do not try to run. It's not a code.
+components
|-+BigComp
  |-Index.jsx
  |-ElemOfBigComp0.jsx
  |-ElemOfBigComp1.jsx
  |-ElemOfBigComp2.jsx
+styles
|-+BigComp
  |-index.sass
  |-elem0.sass
  |-elem1.sass// webpack.config.js
const path = require('path');
const rules = [
  {
    test: /\.s[ac]ss$/,
    use: [
     'css-loader',
     'sass-loader',
    ],
  },
  {
    test: /\.jsx?$/,
    use: ['babel-loader'],
    exclude: ['/node_modules'],
  },
];
module.exports = {
  entry: './src/index.js',
  output: {
    filename: 'bundle.js',
    path: path.resolve(__dirname, 'dist')
  },
  resolve: {
    extensions: ['.js', '.jsx'],
  },
  module: { rules },
};