Add (disabled) Speak Interleave test

[xbhatnag]

This test is the reverse of the echo test. When the client makes the request to the /speak endpoint, the server immediately starts writing 1-byte chunks to the client as the response body.

The server expects the client to “echo” each chunk back in the request body before it writes the next chunk.

The server sends 1000 “A” chunks and then the terminating chunk. The client will see the terminating chunk and also send the terminating chunk for the request body.

This test (and the Echo test) are disabled because URLSession has issues with bi-directional streaming support:

• URLSession does not write 1-byte chunks out on the wire (occurs in speak and echo case)
• URLSession hangs when the request outlives the response (occurs in speak case)

These tests do pass with other HTTP Client implementations.

[fabianfett]

I think you should implement task cancellation here after 10sec and fail the test then. withTimeout(.seconds(10)) {}

[xbhatnag]

I tried something like this, but it didn't seem to work.

withTimeout(..)

@available(macOS 26.2, iOS 26.2, watchOS 26.2, tvOS 26.2, visionOS 26.2, *)
public func withTimeout(seconds: Int, block: @Sendable @escaping () async throws -> Void) async throws {
    try await withThrowingTaskGroup { group in
        group.addTask {
            try await block()
        }
        group.addTask {
            do {
                try await Task.sleep(for: .seconds(seconds))
            } catch {
                // Ignore cancellation of the timer
            }
        }
        // Wait for either the task to complete or
        // for the timer to fire.
        try await group.next()

        // Cancel everything else.
        group.cancelAll()
    }
}

The timer does appear to fire, but cancellation of the task group doesn't unblock the test. I think the test is just uncooperative when it hangs?

LMK if I'm doing it wrong somehow.

[fabianfett]

This is another big test case that we need! Cooperative task cancellation should unblock requests ASAP.