FBSnapshotTestCase integration. Initial tests for AttributedStringView

[Austinate]

This PR adds (#656):

• FBSnapshotTestCase integration:
  • Pod for Test scheme
  • Environment variables to main scheme:
  • Added 'FailureDiffs/' folder signature to .gitignore (we would not want to have images from Failure Diffs in repository)
• 2 simple tests for AttributedStringView (please correct me if there any additional tests needed since i'm not that familiar with codebase yet) :)

[BasThomas]

If we don’t add the snapshots to git, we can only test this locally... is that what we want?

_{Sent with GitHawk}

[Austinate]

@BasThomas actual snapshots are in repo. But we won't store failure diffs, since they should be picked up by CI and/or PR author for investigation :)

[Austinate]

@BasThomas for example we have this in PR (and this should always be part of repo, ofc it doesn't make sense to store reference images locally only),
but if test will fails i will have this in Failure Diffs repo (and this part won't be in repo):

[BasThomas]

Ah, obviously. Nevermind me 😔

[Austinate]

@BasThomas no worries :)

[BasThomas]

Thing is - we use them at work too. Just wasn't thinking. 😅

[Austinate]

@rnystrom hi! I see some conflicts already, should i update PR or we're going to merge this later?

[Austinate]

Hi, @rnystrom
Don't want to be annoying, but do we plan to have any actions on this? If so — i'll rebase, if not — probably would be nice to just close.
Thanks in advance!

[rnystrom]

Hey! Sorry this fell off my radar. Yes! Let's rebase and I'll land.

[Austinate]

@rnystrom Thanks for response! Rebased and ready to go

[Sherlouk]

Haven't seen the source for this tweet, but sounds like FBSnapshotTestCase might not be maintained any more?

https://twitter.com/amlcurran/status/933002258790387713

[Austinate]

@Sherlouk source is here
tl;dr: Unfortunately I recently archived the project as we no longer use this internally ... I am working on a solution though to provide a better owner for it. I'll keep you posted.

So i think there is a big chance that this still will be maintained

[rnystrom]

We use this at Instagram, it's a wonderful tool for building UI w/out having to spin up the entire app. Not to mention regression testing.