What's the idea behind compressing cached output

[thymikee]

Babel Loader Version:
current (8.0.0-beta.0) but I believe it stays since beginning (or at least 6.x)

Current behavior:
When cacheDirectory option is set, babel-loader stores the cached transforms as compressed files (using zlib).

Expected/desired behavior:
I'm actually curious what's the idea behind compressing cache?

The only reason I can see is to make node_modules take less place (as node_modules/.cache/babel-loader is the default cache dir)

The drawback, however, is spending quite some time compressing and decompressing (not to mention stringifying and parsing prior to that).

Would you be interested in accepting a PR that at least would make compression customisable?

[thymikee]

BTW, I have a working PoC locally.
For 2.5k files transformed I've seen ~2.1% improvement (cache size jumped from 7.9MB to 30.1MB) on cold run, Node v9.2.0.

It doesn't seem much but it's always something, especially when you transpile a lot modules, like in React Native projects for example, or have 10k+ components.