Fix Failing UnitTests

[jaxdesmarais]

Summary of changes

• BTSEPADirectDebitClient_Tests.testTokenizeWithPresentationContext_handleCreateMandateReturnsInvalidURL_returnsError_andSendsAnalytics()
  • We were returning a cannedErrorResponse here which wasn't needed and was actually returning before the method completed
• BTJSON_Tests.testLargerMixedJSONWithEmoji()
  • "aString": "Hello, JSON 😍!" and "anInvalidURL": ":™£¢://://://???!!!" were failing to evaluate as nil when calling BTJSON.asURL() - neither of these are URLs so we expect that method to evaluate as nil
  • Adding a check of urlString.utf8.count == urlString.utf16.count allows us to evaluate the string in the same way that we were in Obj-C
  • More details on this test as a whole below...

The Why

I found this super interesting so adding it here if other folks are also interested:

• NSString - these are UTF-16 (more reading here)
• String - these are UTF-8 (more reading here)
• The testLargerMixedJSONWithEmoji test has been failing because "😍" is 2 extra bytes in UTF-8 vs UTF-16 and "™£¢" is 4 extra bytes in UTF-8 vs UTF-16
• Lots of discussions about eventually adding some logic around this to Foundation directly in the Swift forums

Alternatives

There are some alternatives to the check I added here that we can explore, but the approach I took was the closest to our v5 implementation here which used asString to see if it could be cast to a NSString (UTF-16) and if not returned null. Some alternatives:

• Cast urlString to NSString - downside, we would then need to cast it back to a string in return URL(string: urlString) because NSString is not implicitly convertible to String
• Using something like UIApplication.shared.canOpenURL could be an option but we would need to replace our URLs in tests with actual URLs. This also seems like overkill a bit imo, but open to opinions!
• ... maybe something I haven't thought of yet?

Checklist

• [ ] Added a changelog entry

Authors

• @jaxdesmarais

[agedd]

this is pretty cool ~ it was interesting to learn about how utf-8 and utf-16 are different on a byte level - thanks for linking these articles in your pr! 🎉