webpack.config.js

const path = require('path');
module.exports = {
    module: {
        rules: [
            {
                loader: 'raw-loader',
                test: /\.(glsl|frag|vert)$/,
                include: [ path.resolve(__dirname, "build/node_modules/") ],
            },
            {
                loader: 'glslify-loader',
                test: /\.(glsl|frag|vert)$/,
                include: [ path.resolve(__dirname, "build/node_modules/") ]
            }
        ]
    }
}