All about Testing

[vnphanquang]

Context

Merged from #65, #69, #111

All packages have been implemented without any tests. This is okay since most packages have been generally tested during past implementations in my previous project. However, this is not a very stable path to go with because features & refactors might break a lib anytime and go under notice until somewhere in some production.

This issue is to track and discuss testing for all libs within @svelte-put.