Make builds deterministic

[fu5ha]

Fix/improvement based on #735

Makes asset ids the last 5 characters of the md5 hash of the path of that asset.

[fu5ha]

wip... still looking to improve this and pass all the tests

[codecov-io]

Codecov Report

Merging #780 into master will decrease coverage by 0.13%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #780      +/-   ##
==========================================
- Coverage   94.02%   93.88%   -0.14%     
==========================================
  Files          65       65              
  Lines        2174     2175       +1     
==========================================
- Hits         2044     2042       -2     
- Misses        130      133       +3

Impacted Files	Coverage Δ
src/Asset.js	97.75% <100%> (+0.02%)	⬆️
src/assets/CSSAsset.js	82.35% <0%> (-7.36%)	⬇️
src/Logger.js	96.96% <0%> (+1.51%)	⬆️
src/WorkerFarm.js	93.22% <0%> (+1.69%)	⬆️

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[fu5ha]

Alright this passes tests now. Main downside is that it could increase minified file sizes a small amount and it may very slightly affect performance, maybe noticeable for projects with a very large number of assets.

[jeanfortheweb]

I had a similar approach a few days ago, but I used the Asset name itself since it's already the absolute asset path itself which should be perfect for unique ID's. Anyway, I also discovered that assets are forced to be unique created inside the bundler, therefore the current ID generation should already deterministic as long as the assets do not change. If that's not the case, then the files are not getting read in the same order every time.

At least I would think about moving the asset creation from Bundler.js:259 (on 1.4.1) to the Asset itself using a factory pattern. Guess that would make it a lot easier to reason about.

[fu5ha]

That's what I did originally, but they change across different machines/operating systems. Using a normalized relative path seems to be the best options as far as that goes. See #735 for discussion/my findings about why this isn't happening--ultimately I reached a similar conclusion to you. Something's going on where assets are being loaded multiple times and not always in the same order which is why the current system doesn't work properly.. possibly because of the way workers are used to parallelize the work.

[jeanfortheweb]

Just a guess but it shouldn't happen at load time, since this is happening in the main thread on the bundler... hmmm, well if the loading order depending on the native file system layer can't be deterministic then these IDs will also never be. But I like the simplicity of numeric IDs, actually.