// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using Microsoft.Build.Evaluation;
using Shouldly;
using Xunit;
 
#nullable disable
 
namespace Microsoft.Build.UnitTests.Evaluation
{
    public class ProjectCollection_Tests
    {
        [Fact]
        public void ProjectRootElementCache_IsDeterminedByEnvironmentVariable()
        {
            using var collectionWithDefaultCache = new ProjectCollection();
            collectionWithDefaultCache.ProjectRootElementCache.ShouldBeOfType<ProjectRootElementCache>();
 
            const string envKey = "MsBuildUseSimpleProjectRootElementCacheConcurrency";
 
            using (TestEnvironment env = TestEnvironment.Create())
            {
                env.SetEnvironmentVariable(envKey, "true");
                using var collectionWithSimpleCache = new ProjectCollection();
                collectionWithSimpleCache.ProjectRootElementCache.ShouldBeOfType<SimpleProjectRootElementCache>();
            }
        }
    }
}