list-reminder.swift

//import Cocoa
//var str = "Hello, playground"
import EventKit

let eventStore = EKEventStore()

func allowAuthorization() {
    if getAuthorization_status() {
        // 許可されている
        return
    } else {
        // 許可されていない
        eventStore.requestAccess(to:.event, completion: {
            (granted, error) in
            if granted {
                return
            }
            else {
                print("Not allowed")
            }
        })
        
    }
}

// 認証ステータスを確認する
func getAuthorization_status() -> Bool {
    // 認証ステータスを取得
    let status = EKEventStore.authorizationStatus(for:.event)
    
    // ステータスを表示 許可されている場合のみtrueを返す
    switch status {
    case .notDetermined:
        print("NotDetermined")
        return false
        
    case .denied:
        print("Denied")
        return false
        
    case .authorized:
        print("Authorized")
        return true
        
    case .restricted:
        print("Restricted")
        return false
    }
}

allowAuthorization()
// getAuthorization_status()



func viewDidLoad() {
//    eventStore = EKEventStore()
    eventStore.requestAccess(to: .reminder) { (granted, error) in
    print("OK")
//            let allReminders = EKReminder()
            let cals = eventStore.calendars(for: .reminder)
            let predicate = eventStore.predicateForIncompleteReminders(withDueDateStarting: nil, ending: nil, calendars: cals)
            
            eventStore.fetchReminders(matching: predicate, completion: { (reminders: [EKReminder]?) -> Void in
                print(reminders!)
                var a: [[String:Any]] = []
                for reminder: EKReminder? in reminders! as [EKReminder?] ?? [EKReminder?]() {
                    a.append(["title": reminder?.title as Any])
                }
                do {
                let data = try JSONSerialization.data(withJSONObject: a)
                    let s = String(data: data, encoding: String.Encoding.utf8)
                    print(s!)
                } catch let err {
                    print(err)
                }
            })
    }
}

viewDidLoad()
print(".")

Works on Playground, but doesn't work with swift command in iTerm2.
The latter returns empty.