Sitecore Content Search Unit Test

ContentSearchTest.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using Moq;
using NUnit.Framework;
using Sitecore.ContentSearch;
using Sitecore.ContentSearch.Linq;
using Sitecore.ContentSearch.SearchTypes;

namespace Website
{
    [TestFixture]
    public class ContentSearchTest
    {
        [Test]
        public void GetProductsTest()
        {
            // arrange
            var repository = new TestableSearchRepository();

            // act
            var products = repository.GetProducts(null);

            // assert
            Assert.AreEqual(2, products.Count());
        }
    }

    public class ProductSearchResultItem : SearchResultItem
    {
        [IndexField("free")]
        public virtual bool Free { get; set; }
    }


    public class SearchRepository
    {
        public virtual IEnumerable<ProductSearchResultItem> GetProducts(SitecoreIndexableItem item)
        {
            using (var context = this.GetSearchContext(item))
            {
                var query = context.GetQueryable<ProductSearchResultItem>();

                var allProducts = query.GetResults();

                var products = query.Filter(searchResultItem => searchResultItem.Free);

                return products.ToList();
            }
        }

        protected virtual IProviderSearchContext GetSearchContext(SitecoreIndexableItem item)
        {
            return ContentSearchManager.CreateSearchContext(item);
        }
    }

    public class TestableSearchRepository : SearchRepository
    {
        protected override IProviderSearchContext GetSearchContext(SitecoreIndexableItem item)
        {
            // create the magic product index
            var index = new List<ProductSearchResultItem>();

            index.Add(new ProductSearchResultItem { Free = true });
            index.Add(new ProductSearchResultItem { Free = false });
            index.Add(new ProductSearchResultItem { Free = true });

            // create the mock context
            var context = new Mock<IProviderSearchContext>();
            context.Setup(c => c.GetQueryable<ProductSearchResultItem>()).Returns(index.AsQueryable());
            return context.Object;
        }
    }

    public static class ExtensionMocks
    {
        public static SearchResults<TSource> GetResults<TSource>(this IQueryable<TSource> source)
        {
            return new SearchResults<TSource>(source.Select(s => new SearchHit<TSource>(0, s)), 0);
        }

        public static IQueryable<TSource> Filter<TSource>(this IQueryable<TSource> source, Expression<Func<TSource, bool>> predicate)
        {
            return source.Where(predicate);
        }
    }
}

When trying your solution I found the ExtensionMocks only worked when in the same assembly as GetResults is executed. This doesn't work when the unit tests are in a separate project. I have come up with an alternate solution which uses a test double for IQueryable and IQueryProvider then provides the missing Execute method that GetResults relies on.

This is really useful, but in case anyone ends up in the same situation as me, this doesn't work for queries involving facets.