truncate all tables in RealmSwift

Realm+truncateAll.swift

import RealmSwift

extension Realm {
    static func truncateAll(`in` realm: Realm) {
        for objectScheme in realm.schema.objectSchema {
            if let clazz = Realm.clazz(fromClassName: objectScheme.className) {
                try! clazz.deleteAll(in: realm)
            }
        }
    }
    
    static func clazz(fromClassName: String) -> Object.Type? {
        // very fragile...
        let object = String(reflecting: AppDelegate.self)
        let namespace = object.components(separatedBy: ".").first!
        let clazz: AnyClass = NSClassFromString("\(namespace).\(fromClassName)")!
        return clazz as? Object.Type
    }
}

extension Object {
    static func deleteAll(`in` realm: Realm) throws {
        let allObjects = realm.objects(self)
        try realm.write {
            realm.delete(allObjects)
        }
    }
}