The tests make calls to the Resend API which means that the RESEND_API_KEY must be set in order to
run them.
You will notice that some of the tests are slow, there's 2 reasons for this:
- The tests all use a shared client that implements rate-limiting to avoid getting errors from the server
- There are some thread sleep statements here and there to make sure that calls that create a resource have been properly processed
Note that because rate limiting only works for the nonblocking feature, if more non-async tests
are added, it might be necessary to add thread sleeps.
Before implementing or even suggesting a new feature, make sure to check the unreleased section of the Changelog. The reason for that is that sometimes I might implement something but not publish it immediately to avoid flooding crates.io with new releases every time a small change is made. Open an issue about it and I'll be sure to cut a release!