RemoteVersion.swift

import Foundation
import ReactiveSwift
import ReactiveTask
import Result
import Tentacle

/// Synchronously returns the semantic version of the newest release,
/// if the given producer emits it within a reasonable timeframe.
///
public func remoteVersion(_ remoteVersionProducer: SignalProducer<Release, CarthageError>) -> SemanticVersion? {
	let latestRemoteVersion = remoteVersionProducer
		.attemptMap { release -> Result<SemanticVersion, CarthageError> in
			return SemanticVersion.from(Scanner(string: release.tag)).mapError(CarthageError.init(scannableError:))
		}
		// Add timeout on different queue so that `first()` doesn't block timeout scheduling
		.timeout(after: 0.5, raising: CarthageError.gitHubAPITimeout, on: QueueScheduler(qos: .default))
		.first()
	return latestRemoteVersion?.value
}