import frag from './shaders/frag.glsl';
console.log(frag);

// rollup.config.js
import glslify from 'rollup-plugin-glslify';
export default {
    // ...
    plugins: [
        glslify()
    ]
};

glslify(options)

{
    // Default
    include: [
        '**/*.vs',
        '**/*.fs',
        '**/*.vert',
        '**/*.frag',
        '**/*.glsl'
    ],
    // Undefined by default
    exclude: 'node_modules/**',
    // Enabled by default
    compress: true
    // The compress option also accepts a function with its first argument
    // being the string containing the glslified shader code.
    // The function is expected to return a string (or object) - the compressed shader
}