/* In .babelrc */
{
  "presets": ["react"]
}

/* In webpack.config.js */
module.exports = {
    ...
    module: {
        rules: [{
            test: /\.js$/,
            use: ['babel-loader'],
            include: path.join(__dirname, 'src')
        }, {
            test: /\.dsx$/,
            use: ['babel-loader', 'declarity-loader'],
            include: path.join(__dirname, 'src/entities')
        }]
    },
    ...
}