[natecook1000]

This adds a Build / Test [release] step to the tests for macOS and Linux, so that tests can be run in both modes. It includes new inputs for:

• macos_release_build_command (default: xcrun swift test -c release)
• linux_release_build_command (default: swift test -c release)
• enable_release_tests (default: false)

[rauhul]

Why not just run in release always?

[FranzBusch]

Why not just run in release always?

Most packages don't support building tests in release mode due to @testable imports AFAIK

[rauhul]

@testable supports release mode. It just makes internal api visible outside the module unit.

[natecook1000]

Huh, that isn't my experience! I thought it would just be easier to not block on this for packages that couldn't support it fully.

[ahoppen]

I think you need to pass --enable-testable-imports to test a package with @testable imports in release mode.

[jrflat]

FWIW even with --enable-testable-imports, System was still failing to build tests in release mode (due to some #if DEBUG conditionals, fixed by PR above). We would probably need to keep enable_release_tests defaulting to false or otherwise track down/help fix potential failures in projects using this workflow.

[MahdiBM]

The way to enable @testable imports even in release builds is to use -Xswiftc -enable-testing like I've added a few months ago to Vapor's reusable CI for release-mode testing of packages when possible.
I'm not quite sure why --enable-testable-imports doesn't cut it. Could be a bug.

[FranzBusch]

I'm just going to request changes here since we have #316 in-flight which is changing some of the fundamental ways we define the test matrix. We can relayer it on top of that if we still find it useful. It does bring release mode testing with it already.