0.1.0

[mbrandonw]

⏰ A few clocks that make working with Swift concurrency more testable and more versatile.

---

This discussion was created from the release 0.1.0.

[davdroman]

Loving this release!

One question. Am I right in assuming that dot-syntax shorthands are not available due to Swift's lack of extensions on existentials (for now)?

#if compiler(>=5.8) // theoretical Swift version where existential extensions are supported
@available(iOS 16, macOS 13, tvOS 16, watchOS 9, *)
extension any Clock<Duration> {
    @inlinable
    public static var immediate: ImmediateClock { .init() }

    @inlinable
    public static var test: TestClock { .init() }

    @inlinable
    public static func unimplemented(
        name: String = "Clock",
        now: Instant = .init()
    ) -> UnimplementedClock {
        .init(name: name, now: now)
    }
}
#endif

If so, this could make for a compelling snippet in a potential future proposal.

[mbrandonw]

We actually do have support for the dot-syntax shorthands:

swift-clocks/Sources/Clocks/ImmediateClock.swift

Lines 157 to 177 in 7379ef3

	extension Clock where Self == ImmediateClock<Swift.Duration> {
	/// A clock that does not suspend when sleeping.
	///
	/// Constructs and returns an ``ImmediateClock``
	///
	/// > Important: Due to [a bug in Swift](https://github.com/apple/swift/issues/61645), this static
	/// > value cannot be used in an existential context:
	/// >
	/// > ```swift
	/// > let clock: any Clock<Duration> = .immediate // 🛑
	/// > ```
	/// >
	/// > To work around this bug, construct an immediate clock directly:
	/// >
	/// > ```swift
	/// > let clock: any Clock<Duration> = ImmediateClock() // ✅
	/// > ```
	public static var immediate: Self {
	ImmediateClock()
	}
	}

This should allow for things like:

store.dependencies.continuousClock = .immediate

But if you try using them it crashes the compiler 😆. We filed a bug for it:

swiftlang/swift#61645

[davdroman]

Excellent, thanks for surfacing this.

I knew about this crashing the compiler but I thought it was because it wasn't supposed to be used for existentials. Hopefully it's more feasable to have it fixed than to implement a whole new feature.