ladybird/Tests/LibCore/TestEventLoopActor.swift

/*
 * Copyright (c) 2025, Andrew Kaster <andrew@ladybird.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

import AK
import Core
import CoreTesting
import Testing

actor TestEventLoopActor: EventLoopActor {
    nonisolated public let executor: EventLoopExecutor

    init() {
        install_thread_local_event_loop()
        executor = EventLoopExecutor()
    }

    nonisolated func submit(action: @escaping @Sendable () async -> Void) {
        Task(executorPreference: self.executor) {
            await action()
        }
    }
}

@Suite
struct TestEventLoop {
    @Test
    func testEventLoopActor() async {
        // Creates an executor around EventLoop::current()
        let actor = TestEventLoopActor()

        let ev = Core.EventLoop.current()
        print("Event loop at \(Unmanaged.passUnretained(ev).toOpaque())")

        let (stream, continuation) = AsyncStream<Int>.makeStream()
        var iterator = stream.makeAsyncIterator()

        actor.submit {
            #expect(ev == Core.EventLoop.current(), "Closure is executed on event loop")
            print("Hello from event loop at \(Unmanaged.passUnretained(Core.EventLoop.current()).toOpaque())")

            continuation.yield(42)
        }

        actor.submit {
            #expect(ev == Core.EventLoop.current(), "Closure is executed on event loop")
            Core.EventLoop.current().quit(4)

            continuation.yield(1234)
            continuation.finish()
        }

        let rc = ev.exec()
        #expect(rc == 4)
        // Values not available until event loop has processed tasks
        #expect(await iterator.next() == 42)
        #expect(await iterator.next() == 1234)

        #expect(ev == Core.EventLoop.current(), "Event loop exists until end of function")
    }
}