Adjust array src format + add transposition logic

[VeraZab]

No description provided.

[VeraZab]

guards against empty arrays

[VeraZab]

it's easier to have this in an array format to lookup srcs in dataOptions, this behaviour here was broken in current dereferencing function for array srcs

[VeraZab]

@bpostlethwaite ready for review

[nicolaskruchten]

OK so on the src-handling front, the API is a bit murky for me... Right now we expect srcs to either be strings or arrays of strings, correct? And we want to provide a pair of functions that allow someone integrating the editor to be able to pass in some other format (i.e. encoded strings like we have in streambed) and the joinSrc and splitSrc functions are mappings between what the editor wants to process and what is externally needed. So I would rename those toSrc and fromSrc or something, to make it a bit clearer what the API is.

[nicolaskruchten]

I would also have those functions be distinct props, rather than keys in an opaque-looking customSrcHandling object prop :)

[VeraZab]

Thanks @nicolaskruchten ! Made the adjustments.

I think I like keeping the customSrcHandling object because I think it's maybe clearer that both toSrc and fromSrc are needed if we're going to customSrcHandling route. I added Proptypes.shape to make it more explicit what that object contains.

It's ready for a second look when you have a chance.

[nicolaskruchten]

💃 from me on the high-level API. The tests seem good to me.

[nicolaskruchten]

sorry, hit wrong button :)