ln.threading/ln.threading.tests/PromiseTests.cs

using System;
using NUnit.Framework;

namespace ln.threading.tests
{
    public class PromiseTests
    {
        [Test]
        public void Test_A_Promises()
        {
            Promise<int> p = new Promise<int>((resolve,reject)=>{
                resolve(1234);
            });

            Assert.AreEqual(1234, p.Value);

            Assert.AreEqual(
                33,
                new Promise<string>((resolve,reject)=>{
                    resolve("resolved");
                })
                .Then((value)=>{
                    return 4;
                })
                .Then<int>((value)=>{
                    throw new Exception("TestException");
                })
                .Then((value)=>{
                    return value + 16;
                })
                .Catch((e)=>{
                    return 32;
                })
                .Then((value)=>{
                    return value + 1;
                })
                .Then((value)=>{
                    value ++;
                })
                .Value
            );

            Assert.AreEqual(
                23,
                new Promise<string>((resolve,reject)=>{
                    resolve("resolved");
                })
                .Then((value)=>{
                    return 4;
                })
                .Then<int>((value)=>{
                    return value + 2;
                })
                .Then((value)=>{
                    return value + 16;
                })
                .Catch((e)=>{
                    return 32;
                })
                .Then((value)=>{
                    return value + 1;
                })
                .Then((value)=>{
                    value ++;
                })
                .Value
            );  
        }

        [Test]
        public void Test_B_Promises()
        {
            Assert.AreEqual(
                "The magic result is 129",
                createTestPromise(1).Value
                );
            Assert.AreEqual(
                "The magic result is 130",
                createTestPromise(2).Value
                );
            Assert.AreEqual(
                "The magic result is 131",
                createTestPromise(3).Value
                );
            Assert.AreEqual(
                "The magic result is 132",
                createTestPromise(4).Value
                );
            Assert.AreEqual(
                "sorry, I have no result for you",
                createTestPromise(11).Value
                );
        }

        public Promise<string> createTestPromise(int i)
        {
            return new Promise<int>((resolve, reject)=>{
                resolve(i);
            })
            .Then((n)=>{
                if (n== 11)
                    throw new Exception("I don't like 11");
                return n + 128;
            })
            .Then(
                (n)=>{
                    return string.Format("The magic result is {0}", n);
                },
                (e)=>{
                    return "sorry, I have no result for you";
                })
            ;
        }

    }
}