Nimble Next

[younata]

This represents the work for the Nimble 13 Next version.

The idea is to keep this as a draft PR until it's ready. Nimble 13 Next betas will source from this PR.

Work for the next minor version of Nimble will continue to target main, and I'll regularly rebase this PR on top of main to keep it in sync.

Once I feel like we're ready to release this, I'll merge this PR into main.

Contents:

• Make expect+async and AsyncExpression conform to Sendable #1067
• Make expect for async closures take in Sendable closures #1070
• Make the async variants of expect require sendable values #1071
• Make AsyncPredicate Sendable, constrain it to Sendable types #1072
• Update Require DSL to be (mostly) Sendable. #1130
• Make FailureMessage Sendable. #1131
• Make MatcherResult conform to Sendable #1132
• Make the Polling Helpers Sendable #1133
• Make AssertionHandler Sendable #1141
• Fix concurrency warnings for more objective-c/foundation types #1165
• Nimble 14: Fix concurrency warnings in test #1166
• Nimble 14: Make all parts of the dsl must take in sending #1167
• Nimble 14: Remove usage of the swift 6 only sending keyword #1168
• Nimble 14: Fix broken tests in swift 6 #1169

TODO

• Fix all the remaining concurrency warnings

[younata]

Now that we require Sendable closures when using async toEventually/async expressions, this presents an issue integrating with Quick.

In Quick, the common/promoted styling is to declare variables as vars in an ExampleGroup (i.e. describe, context, or even the root example group in the spec method). In Swift 5.9, when you pass a var to a sendable closure, you have to explicitly declare it. i.e.:

var subject: SomeClass!

// ...

it("does something") {
    expect { [subject] in await subject!.value }.to(...)
    // Note: In the closure, the type of `subject` is changed from a force-unwrap optional to a standard optional.
    // that is, the `!` boilerplate is now required.
}

Which is a terrible experience. It would be awfully nice if Swift would let us implicitly capture that var and pass it along.

[younata]

With the merging of #1167, all of the concurrency warnings are fixed (when running on Xcode 16).

Unfortunately, this refuses to build on pre-swift-6 versions of Xcode thanks to the use of sending, and there are even broken tests to go look through.