CombineLatestTests.swift

import XCTest
import ReactiveSwift
import Result

class PerformanceTests: XCTestCase {
	let iterations = 50_000

	func testStackBlowing() {
		func nest(_ signal: Signal<(), NoError>) -> Signal<(), NoError> {
			let (never, o) = type(of: signal).pipe()
			defer { o.send(value: ()) }
			return Signal.combineLatest(never, never, never, never, never, never, never, never, never, signal).map { $0.9 }
		}

		var (signal, observer) = Signal<(), NoError>.pipe()
		var itr = 0

		repeat {
			signal = nest(signal)
			observer.send(value: ())
			itr += 1
			if itr % 50 == 0 {
				print(itr)
			}
		} while itr < 10000
	}

	func testCombineSignalTenary() {
		let (s1, o1) = Signal<Int, NoError>.pipe()
		let (s2, o2) = Signal<Int, NoError>.pipe()
		let (s3, o3) = Signal<Int, NoError>.pipe()

		let combined = Signal.combineLatest(s1, s2, s3)

		o1.send(value: 0)
		o2.send(value: 1)
		o3.send(value: 2)

		combined.observeValues { _ in }

		measure {
			for i in 0 ..< self.iterations {
				o1.send(value: i)
				o2.send(value: i + 1)
				o3.send(value: i + 2)
			}
		}
	}

	func testCombineProducerTernary() {
		let (s1, o1) = Signal<Int, NoError>.pipe()
		let (s2, o2) = Signal<Int, NoError>.pipe()
		let (s3, o3) = Signal<Int, NoError>.pipe()

		let combined = SignalProducer.combineLatest(SignalProducer(s1), SignalProducer(s2), SignalProducer(s3))

		o1.send(value: 0)
		o2.send(value: 1)
		o3.send(value: 2)

		combined.startWithValues { _ in }

		measure {
			for i in 0 ..< self.iterations {
				o1.send(value: i)
				o2.send(value: i + 1)
				o3.send(value: i + 2)
			}
		}
	}

	func testCombineSignal6ary() {
		let (s1, o1) = Signal<Int, NoError>.pipe()
		let (s2, o2) = Signal<Int, NoError>.pipe()
		let (s3, o3) = Signal<Int, NoError>.pipe()
		let (s4, o4) = Signal<Int, NoError>.pipe()
		let (s5, o5) = Signal<Int, NoError>.pipe()
		let (s6, o6) = Signal<Int, NoError>.pipe()

		let combined = Signal.combineLatest(s1, s2, s3, s4, s5, s6)

		o1.send(value: 0)
		o2.send(value: 1)
		o3.send(value: 2)
		o1.send(value: 3)
		o2.send(value: 4)
		o3.send(value: 5)

		combined.observeValues { _ in }

		measure {
			for i in 0 ..< self.iterations {
				o1.send(value: i)
				o2.send(value: i + 1)
				o3.send(value: i + 2)
				o4.send(value: i + 3)
				o5.send(value: i + 4)
				o6.send(value: i + 5)
			}
		}
	}

	func testCombineProducer6ary() {
		let (s1, o1) = Signal<Int, NoError>.pipe()
		let (s2, o2) = Signal<Int, NoError>.pipe()
		let (s3, o3) = Signal<Int, NoError>.pipe()
		let (s4, o4) = Signal<Int, NoError>.pipe()
		let (s5, o5) = Signal<Int, NoError>.pipe()
		let (s6, o6) = Signal<Int, NoError>.pipe()


		let combined = SignalProducer.combineLatest(SignalProducer(s1), SignalProducer(s2), SignalProducer(s3),
		                                            SignalProducer(s4), SignalProducer(s5), SignalProducer(s6))

		o1.send(value: 0)
		o2.send(value: 1)
		o3.send(value: 2)
		o4.send(value: 3)
		o5.send(value: 4)
		o6.send(value: 5)

		combined.startWithValues { _ in }

		measure {
			for i in 0 ..< self.iterations {
				o1.send(value: i)
				o2.send(value: i + 1)
				o3.send(value: i + 2)
				o4.send(value: i + 3)
				o5.send(value: i + 4)
				o6.send(value: i + 5)
			}
		}
	}
}