Rollup Config in Gulp - jQuery External Issue

gulpfile-rollup-issue.js

// ...

// Build JS with Rollup
// ---------------------------------------
gulp.task('js', ['lint-js'], () => {
  console.log('*** Compiling JS ***'.green);
  return rollup.rollup({
    entry: "./src/js/theme.js",
    plugins: [
      resolve({
        jsnext: true,
        main: true,
        browser: true
      }),
      cjs({
        include: [
          'node_modules/**',
          'src/js/vendor/**'
        ]
      }),
      amd(),
      legacy({}),
      inject({
        include: '**/*.js',
        exclude: 'node_modules/**',
        jQuery: 'jquery',
        $: 'jquery',
        jquery: 'jquery'
      }),
      babel({
        exclude: 'node_modules/**' 
      }),
    ],
    external: ['jquery', 'jQuery']
  })
  .then(function (bundle) {
    bundle.write({
      format: 'iife',
      dest: "./theme/assets/theme.js",
      globals: {
        jquery: '$'
      },
    });
  })
});

//...

// demo.js

// Running this code will include jquery in my build if jquery is in my node_modules folder, but fail unless I remove 'external: ['jquery', 'jQuery']' from gulpfile.

// If i remove jquery from node_modules folder - below code works

import $ from 'jquery'
import 'slick-carousel'

export let demo = {

  init() {
    console.log($);  // returns jquery object
    $('.slider').slick();  
  }

}

demo.init();

// slick.js from node_modules

//... 

/* global window, document, define, jQuery, setInterval, clearInterval */
(function(factory) {
    'use strict';
    if (typeof define === 'function' && define.amd) {
        define(['jquery'], factory);
    } else if (typeof exports !== 'undefined') {
        module.exports = factory(require('jquery'));   // <--- F*ck this line in particular
    } else {
        factory(jQuery);
    }

}(function($) {
    'use strict';
    var Slick = window.Slick || {};

    Slick = (function() {

// .....

Goal:

To include a 3rd party lib from npm that requires jquery but keep that dependency external and global.

I am linking to jquery from CDN and would like to keep it that way.