Test request caching when requesting GH notifications

gh-notifications-cache-requests.swift

import Foundation

func fetch(cachePolicy: URLRequest.CachePolicy) {
    let apiToken = ProcessInfo.processInfo.environment["GITHUB_API_TOKEN"]!
    var request = URLRequest(url: URL(string: "https://api.github.com/notifications?all=false&participating=true")!, cachePolicy: cachePolicy)
    request.addValue("token \(apiToken)", forHTTPHeaderField: "Authorization")
    request.addValue("no-cache", forHTTPHeaderField: "Cache-Control")
    URLSession.shared.dataTask(with: request) { _, response, _ in
        guard let httpResponse = response as? HTTPURLResponse else { return }
        let headers = httpResponse.allHeaderFields
        let df = DateFormatter()
        df.dateFormat = "yyyy-MM-dd HH:mm:ss"
        print(df.string(from: Date()), "Cache-Control:", headers["Cache-Control"]!, "Etag:", headers["Etag"] ?? "?", "Date:", headers["Date"]!)
    }.resume()
}

fetch(cachePolicy: .useProtocolCachePolicy)
Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { _ in
    fetch(cachePolicy: .useProtocolCachePolicy)
}

RunLoop.current.run()