How to run/terminate shell command when starting/finishing iOS tests?

I am trying to write an integration test for my iOS app & our API server. Both are in the same repo, so this test would prevent merging any changes that would break their ability to communicate.

The server team has created a bash script that I need to call to start a local copy of the API server. That script will run until it is terminated. How can I run that script when I run my iOS integration test? I can't put it as part of the build phase as the build will wait for it to terminate before it lets the build finish. I can't use Process directly in my tests to launch the script because that's only available on the Mac, not to iOS targets. Refactoring all my networking & model code to it's own framework that supports iOS & Mac targets would work, but that's a sizable refactor to do. Are there any other ways to run commands along with tests? I'm just using XCTest for all my tests.