TestHelper.cs

using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Net.Http.Formatting;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc.WebApiCompatShim;
using Microsoft.Extensions.Options;
using Moq;

namespace Messaging.Tests
{
    public static class TestHelpers
    {
        public static HttpRequestMessage SetupHttp(HttpRequestMessage requestMessage)
        {
            var services = new Mock<IServiceProvider>(MockBehavior.Strict);
            var formatter = new XmlMediaTypeFormatter();
            var context = new DefaultHttpContext();

            var contentNegotiator = new Mock<IContentNegotiator>();
            contentNegotiator
                .Setup(c => c.Negotiate(It.IsAny<Type>(), It.IsAny<HttpRequestMessage>(), It.IsAny<IEnumerable<MediaTypeFormatter>>()))
                .Returns(new ContentNegotiationResult(formatter, mediaType: null));

            var options = new WebApiCompatShimOptions();

            if (formatter == null)
            {
                options.Formatters.AddRange(new MediaTypeFormatterCollection());
            }
            else
            {
                options.Formatters.Add(formatter);
            }

            var optionsAccessor = new Mock<IOptions<WebApiCompatShimOptions>>();
            optionsAccessor.SetupGet(o => o.Value).Returns(options);

            services.Setup(s => s.GetService(typeof(IOptions<WebApiCompatShimOptions>))).Returns(optionsAccessor.Object);

            if (contentNegotiator != null)
            {
                services.Setup(s => s.GetService(typeof(IContentNegotiator))).Returns(contentNegotiator);
            }

            context.RequestServices = CreateServices(contentNegotiator.Object, formatter);
            requestMessage.Properties.Add(nameof(HttpContext), context);
            return requestMessage;
        }

        private static IServiceProvider CreateServices(
            IContentNegotiator contentNegotiator = null,
            MediaTypeFormatter formatter = null)
        {
            var options = new WebApiCompatShimOptions();

            if (formatter == null)
            {
                options.Formatters.AddRange(new MediaTypeFormatterCollection());
            }
            else
            {
                options.Formatters.Add(formatter);
            }

            var optionsAccessor = new Mock<IOptions<WebApiCompatShimOptions>>();
            optionsAccessor.SetupGet(o => o.Value).Returns(options);

            var services = new Mock<IServiceProvider>(MockBehavior.Strict);
            services.Setup(s => s.GetService(typeof(IOptions<WebApiCompatShimOptions>))).Returns(optionsAccessor.Object);

            if (contentNegotiator != null)
            {
                services.Setup(s => s.GetService(typeof(IContentNegotiator))).Returns(contentNegotiator);
            }

            return services.Object;
        }
    }
}