I think there's an issue with tests in Julia:

decodemorse("----. ---.. --... -.... ..... ....- ...-- ..--- .---- -----") --> "9 8 7 6 5 4 3 2 1 0"

These characters don't have 4 spaces between them, so the output should be one word per the instructions. Am I missing something?

Thanks for the edits! I've done all but packing all testing code within the call to test_that. It seems cleaner to have test setup separate from the actual tests so that what test_that is testing is clear. Happy to try everything in test_that if that's accepted practice here.

Might as well add some multiple dispatch. Julia people, is this the right way to handle these inputs or are conditionals more "julian"?