CompareToDiffingExtensionsTest.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using Bunit.SampleComponents;
using Bunit.TestUtililities;
using Shouldly;
using Xunit;

namespace Bunit
{
    public class CompareToDiffingExtensionsTest : ComponentTestFixture
    {
        /// <summary>
        /// Returns an array of arrays containing:
        /// (MethodInfo methodInfo, string argName, object[] methodArgs)
        /// </summary>
        /// <returns></returns>
        public static IEnumerable<object[]> GetCompareToMethods()
        {
            var methods = typeof(CompareToExtensions)
                .GetMethods()
                .Where(x => x.Name.Equals(nameof(CompareToExtensions.CompareTo), StringComparison.Ordinal))
                .ToList();

            foreach (var method in methods)
            {
                var p1Info = method.GetParameters()[0];
                var p2Info = method.GetParameters()[1];
                object p1 = p1Info.ParameterType.ToMockInstance();
                object p2 = p2Info.ParameterType.ToMockInstance();

                yield return new object[] { method, p1Info.Name!, new object[] { null!, p2! } };
                yield return new object[] { method, p2Info.Name!, new object[] { p1!, null! } };
            }
        }

        [Theory(DisplayName = "CompareTo null values throws")]
        [MemberData(nameof(GetCompareToMethods))]
        public void Test001(MethodInfo methodInfo, string argName, object[] args)
        {
            Should.Throw<TargetInvocationException>(() => methodInfo.Invoke(null, args))
                .InnerException
                .ShouldBeOfType<ArgumentNullException>()
                .ParamName.ShouldBe(argName);
        }

        [Fact(DisplayName = "CompareTo with rendered fragment and string")]
        public void Test002()
        {
            var rf1 = RenderComponent<Simple1>((nameof(Simple1.Header), "FOO"));
            var rf2 = RenderComponent<Simple1>((nameof(Simple1.Header), "BAR"));

            rf1.CompareTo(rf2.Markup).Count.ShouldBe(1);
        }

        [Fact(DisplayName = "CompareTo with rendered fragment and rendered fragment")]
        public void Test003()
        {
            var rf1 = RenderComponent<Simple1>((nameof(Simple1.Header), "FOO"));
            var rf2 = RenderComponent<Simple1>((nameof(Simple1.Header), "BAR"));

            rf1.CompareTo(rf2).Count.ShouldBe(1);
        }

        [Fact(DisplayName = "CompareTo with INode and INodeList")]
        public void Test004()
        {
            var rf1 = RenderComponent<Simple1>((nameof(Simple1.Header), "FOO"));
            var rf2 = RenderComponent<Simple1>((nameof(Simple1.Header), "BAR"));

            var elm = rf1.Find("h1");            
            elm.CompareTo(rf2.Nodes).Count.ShouldBe(1);
        }

        [Fact(DisplayName = "CompareTo with INodeList and INode")]
        public void Test005()
        {
            var rf1 = RenderComponent<Simple1>((nameof(Simple1.Header), "FOO"));
            var rf2 = RenderComponent<Simple1>((nameof(Simple1.Header), "BAR"));

            var elm = rf1.Find("h1");            
            rf2.Nodes.CompareTo(elm).Count.ShouldBe(1);
        }
    }
}