Explore a new Packager: ESBuild

[NullVoxPopuli]

This is super WIP, and I don't have planned dedicated time to work on this, so.. we'll see how long this takes :D

ESBuild is still considered experimental (esp their plugin system), but I want to start a couple things with this PR:

• track what remaining work needs to happen for ESBuild to be supported
• Demonstrate how a packager can be implemented that isn't webpack
• Potentially further extract shared utilities between multiple packagers

[ef4]

This is good to work on.

My starting suggestion is to configure an ember app like this:

  process.env.STAGE2_ONLY = 'true';
  return compatBuild(app, null, {
    staticAddonTrees: true,
    staticAddonTestSupportTrees: true,
    staticComponents: true,
    staticHelpers: true,
    workspaceDir: '../out-ember-app',
  });

and run ember s. Then you can work inside ../out-ember-app which will be very close to consumable by esbuild. The main thing you'll need to adapt is that it will contain _babel_config_.js which you will need to translate into the esbuild equivalents, and _template_compiler_.js which you will need to install to handle .hbs files.

[ef4]

I've just been going through this same exercise for snowpack and vite.

You will most likely want the work on this branch which I haven't had a chance to bring back into master yet.

[NullVoxPopuli]

Gonna close this, because PR #759 from @alexlafroscia looks amazing! (and way more complete).
Also, Vite is on top of ESBuild! https://vitejs.dev/config/#esbuild (I had no idea!)

<3