Investigate Slowness on Dev Server

[allthesignals]

What is causing the rebuild/refresh slowness for the dev server? The refresh seems slower than it does for other projects.

[bfreeds]

Baseline

Initial Build

After initial build - hot reloading template changes

After Initial Build - hot reloading sass changes (related, #354 has been merged in the branch running this).

Resources / Research

• EmberMaps discussion on Ember hot reloading
• Suggestion/idea to move node_modules to RAM
  • I don't propose we do this - to intervene in this low-level way I feel could ultimately make DX difficult and present unique, difficult to ID/troubleshoot challenges down the road.
• Ember CLI Discussion on in-memory server: [Feature request] in-memory file server & build tool ember-cli/ember-cli#7765
  • This is more focused on the known issue with performance on Windows, not sure how relevant it is to what we're experiencing.

[bfreeds]

It looks like the rebuild times when changing hbs or js files is pretty quick, and the bottleneck is primarily being caused by the SASS compiler.

This is a known, open issue from 2015: adopted-ember-addons/ember-cli-sass#74

[bfreeds]

During standup today, @godfreyyeung reported having ~6 second rebuild times. Need to examine packages and what might be different from Zola (which doesn't have such a slow rebuild).

[bfreeds]

Checking ZOLA to see if there's differences in observed performance and project setup:

Rebuilding after change to template:

Rebuilding after change to SASS

[bfreeds]

We should track this open PR, which I think will improve sass compile time: adopted-ember-addons/ember-cli-sass#215.

The other path for investigating is to hook up brocolli-inspector to get a deeper look at what the problem areas are. @allthesignals I'm not sure how the Usage fits with our monorepo, where the server/index.js the setup requires would go.

[allthesignals]

@bfreeds we could try to install that branch of ember-cli-sass on our project and see if it addresses the issue.

[allthesignals]

We cut down the rebuild time significantly. Closing for now but could improve the SASS build time issues in the future.