I was running into strange unit test failures while testing a PR, failures unrelated to the PR work, and (eventually) realized it was related to the primary language of the Simulator I was running the tests on. Some of unit tests rely on English language strings and US region specific formatting to be considered successes.
I think at minimum for the time being we should at least document that the unit tests require the device's language/region to be en-US.
- Set your device/Simulator's primary language to something other than English and region to something other than US in Settings > General > Language & Region (e.g. French/France)
- Run the app's unit tests against that Simulator
All tests succeed.
Some tests fail.