Coverage Summary for Class: FeaturesKt (dev.suresh.lang)

 package dev.suresh.lang
 
 import kotlin.contracts.contract
 
 class Logger(val name: String) {
   fun log(message: String) = println("$name: $message")
 }
 
 context(Logger)
 fun store(msg: String) {
   log("Stored $msg in the file")
 }
 
 fun main() {
   val logger = Logger("main")
   with(logger) { store("Hello") }
 
   val anon = User.Anonymous
   val auth = User.Authenticated("Suresh")
 
   smartCast(anon)
   smartCast(auth)
 }
 
 fun smartCast(user: User) =
     when (user.isAuthenticated()) {
       true -> user.signOut()
       false -> user.signIn()
     }
 
 sealed class User {
 
   fun isAuthenticated(): Boolean {
     contract {
       returns(true) implies (this@User is Authenticated)
       returns(false) implies (this@User is Anonymous)
     }
     return this is Authenticated
   }
 
   data object Anonymous : User() {
     fun signIn() = println("Please sign in")
   }
 
   data class Authenticated(val name: String) : User() {
     fun signOut() = println("Signing out $name")
   }
 }