Add closure compiler

[jaredpalmer]

Steal it from here : https://github.com/ReactTraining/history/blob/dev/rollup.config.js

[ambroseus]

1st impression: it works :)
(test react app also works with compiled package)
just need to tune up configuration for typescript2 plugin:
https://github.com/ezolenko/rollup-plugin-typescript2#plugins-using-asyncawait
objectHashIgnoreUnknownHack: true
result:

[ambroseus]

oh, I see difference in bundle size:
minified with terser: ~ 13900 b
with closure compiler: ~ 12700 b
(compilation_level: 'ADVANCED_OPTIMIZATIONS')

[swyxio]

good! what are the tradeoffs of simple vs advanced optimization?

we should try running against formik to get a good gauge on % savings

nice work so far!

[ambroseus]

good! what are the tradeoffs of simple vs advanced optimization?

SIMPLE_OPTIMIZATIONS do same things as Terser plugin (and in my case optimized bundle size was little bit larger than terser's one)
https://developers.google.com/closure/compiler/docs/api-tutorial3

BUT. there was a problem with 'ADVANCED_OPTIMIZATIONS' level in my lib with regeneratorRuntime polyfill

[ambroseus]

can be implemented as tsdx plugin

[DrSensor]

Dynamic import doesn't work on the closure compiler 🤔
google/closure-compiler#2770