Choose testing framework and create initial tests

[Inwerpsel]

Due to the experimental nature, no tests were added yet, since the implementation and features can still change a lot, and there's also no production use case to worry about yet. For now this is fine and overall much faster to develop. Enough manual testing happens to catch most issues early on.

It would be nice to already have a testing framework in place together with the first tests for some functionality that can be considered stable enough.

Todo

• Pick a good and future proof testing framework(s). Options: Jest, Puppeteer
• Determine some good tests to start with
• Find good performance testing framework (if a framework is needed at all for this)

Which code to start with

Some options:

• Drag and drop rearrangement consistency
• Performance of inspection
• Parts of state management that have complex internals