issue/2824 Switch to rollup from requirejs

[oliverfoster]

#2824
This version does not have the react elements, it is merely to fix the currently broken build process in v5.

Will provide an almost seamless migration away from build-side requirejs and AMD modules to ES6 modules.

Facilitates

• future proof
  • import and export directives
  • beyond ES8 code
• development improvements
  • much faster compilation and recompilation times on all grunt tasks, this is as a cache is now generated for the build process
  • supports larger code bases
  • move towards supporting intellisense in code editors
• backward-compatibility
  • ES6 modules are reregistered in the browser as AMD modules, so var Adapt = require('core/js/adapt'); etc will still work in the console and for other plugins
  • we can now rework Adapt to ES6 modules whilst retaining support for the existing AMD modules
  • still ie11 compatible

Downsides

• External modules such as libraries/mediaelement-fullscreen-hook.js, which are required by internal modules and require internal modules are now considered circular dependencies and will break the loading process. A temporary fix is included until that module can be moved back into the js folder
• Jumping to class function line numbers from the code inspector in the debugger is out of order as the define/require directive conversions moves the line numbers
• Currently this will only work with transpilation back to ES5 as calling an ES6 constructor function without the new keyword is not allowed - which is an essential part of the way Backbone constructs classes.

Added

• rollup as the bundler
• babel is used as the compiler/transpiler through the rollup plugin
• babel-plugin-transform-amd-to-es6 (custom made) to convert AMD modules to ES6 modules
• rollup compilation cache lives at <%= outputdir %>/.cache to speed up compilation times
• jsconfig.json to support intellisense
• grunt flag --disable-cache to disable the cache and recompile from scratch

Removed

• requirejs as bundler in grunt
• babel grunt task is now integrated into the rollup process
• requirejs config.js file has been moved to the javascript grunt task config

Fixed

• QuestionView has two different return statements, so cannot resolve to one export default directive

Testing

• Use master of all plugins by running:

git clone https://github.com/adaptlearning/adapt_framework 2824
cd 2824
git checkout issue/2824
adapt devinstall && npm install
grunt dev

Example

Shows fast compilation times, import/export, debugging and require functioning with an ES6 module in the client-side:

[cahirodoherty-learningpool]

👀

[cahirodoherty-learningpool]

👀

[chris-steele]

Looks fantastic, only issue I saw was a childViews reference runtime error with master branch of adapt-contrib-boxMenu, but works fine using latest release of said menu. 👍

[oliverfoster]

@moloko Could you +1 when you get a mo?

[moloko]

code 👓