// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using System;
using System.Runtime.CompilerServices;
using CommunityToolkit.HighPerformance;
using Microsoft.VisualStudio.TestTools.UnitTesting;

namespace CommunityToolkit.HighPerformance.UnitTests.Extensions;

[TestClass]
public class Test_StringExtensions
{
    [TestMethod]
    public void Test_StringExtensions_DangerousGetReference()
    {
        string text = "Hello, world!";

        ref char r0 = ref text.DangerousGetReference();
        ref char r1 = ref Unsafe.AsRef(in text.AsSpan()[0]);

        Assert.IsTrue(Unsafe.AreSame(ref r0, ref r1));
    }

    [TestMethod]
    public void Test_StringExtensions_DangerousGetReferenceAt_Zero()
    {
        string text = "Hello, world!";

        ref char r0 = ref text.DangerousGetReference();
        ref char r1 = ref text.DangerousGetReferenceAt(0);

        Assert.IsTrue(Unsafe.AreSame(ref r0, ref r1));
    }

    [TestMethod]
    public void Test_StringExtensions_DangerousGetReferenceAt_Index()
    {
        string text = "Hello, world!";

        ref char r0 = ref text.DangerousGetReferenceAt(5);
        ref char r1 = ref Unsafe.AsRef(in text.AsSpan()[5]);

        Assert.IsTrue(Unsafe.AreSame(ref r0, ref r1));
    }
}