* Migrate tests to xunit

* Update sample project to dotnetcore3.1
* Use Sqlite in sample project to run it everywhere
* Fix: Filter with escaped comma
* Fix: Filter "null" does not work with Contains or StartsWith
* Code cleanup: Adjust namespaces, adjust usings

.gitignore

@@ -261,3 +261,9 @@ paket-files/
 # Python Tools for Visual Studio (PTVS)
 __pycache__/
 *.pyc
+
+# Nuke output
+/output
+
+# Sample database
+Sieve.Sample/Sieve.db

Sieve.Sample/Controllers/PostsController.cs

@@ -2,10 +2,10 @@
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.EntityFrameworkCore;
 using Sieve.Models;
+using Sieve.Sample.Entities;
 using Sieve.Services;
-using SieveTests.Entities;
 
-namespace SieveTests.Controllers
+namespace Sieve.Sample.Controllers
 {
     [Route("api/[controller]/[action]")]
     public class PostsController : Controller

Sieve.Sample/Entities/ApplicationDbContext.cs

@@ -1,6 +1,6 @@
 using Microsoft.EntityFrameworkCore;
 
-namespace SieveTests.Entities
+namespace Sieve.Sample.Entities
 {
     public class ApplicationDbContext : DbContext
     {

Sieve.Sample/Entities/Post.cs

@@ -2,14 +2,14 @@
 using System.ComponentModel.DataAnnotations.Schema;
 using Sieve.Attributes;
 
-namespace SieveTests.Entities
+namespace Sieve.Sample.Entities
 {
     public class Post
     {
         public int Id { get; set; }
 
         [Sieve(CanFilter = true, CanSort = true)]
-        public string Title { get; set; } = Guid.NewGuid().ToString().Replace("-", string.Empty).Substring(0, 8);
+        public string Title { get; set; } = Guid.NewGuid().ToString().Replace("-", string.Empty)[..8];
 
         [Sieve(CanFilter = true, CanSort = true)]
         public int LikeCount { get; set; } = new Random().Next(0, 1000);

Sieve.Sample/Migrations/20210513114647_Initial.Designer.cs

@@ -0,0 +1,52 @@
+// <auto-generated />
+using System;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using Sieve.Sample.Entities;
+
+namespace Sieve.Sample.Migrations
+{
+    [DbContext(typeof(ApplicationDbContext))]
+    [Migration("20210513114647_Initial")]
+    partial class Initial
+    {
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "3.1.14");
+
+            modelBuilder.Entity("Sieve.Sample.Entities.Post", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int?>("CategoryId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("CommentCount")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<DateTimeOffset>("DateCreated")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime>("DateLastViewed")
+                        .HasColumnType("datetime");
+
+                    b.Property<int>("LikeCount")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Title")
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("Posts");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

Sieve.Sample/Migrations/20210513114647_Initial.cs

@@ -1,10 +1,9 @@
 using System;
-using Microsoft.EntityFrameworkCore.Metadata;
 using Microsoft.EntityFrameworkCore.Migrations;
 
-namespace SieveTests.Migrations
+namespace Sieve.Sample.Migrations
 {
-    public partial class Init : Migration
+    public partial class Initial : Migration
     {
         protected override void Up(MigrationBuilder migrationBuilder)
         {
@@ -13,14 +12,18 @@ namespace SieveTests.Migrations
                 columns: table => new
                 {
                     Id = table.Column<int>(nullable: false)
-                        .Annotation("SqlServer:ValueGenerationStrategy", SqlServerValueGenerationStrategy.IdentityColumn),
+                        .Annotation("Sqlite:Autoincrement", true),
+                    Title = table.Column<string>(nullable: true),
+                    LikeCount = table.Column<int>(nullable: false),
                     CommentCount = table.Column<int>(nullable: false),
                     DateCreated = table.Column<DateTimeOffset>(nullable: false),
-                    LikeCount = table.Column<int>(nullable: false),
-                    Title = table.Column<string>(nullable: true),
+                    DateLastViewed = table.Column<DateTime>(type: "datetime", nullable: false),
                     CategoryId = table.Column<int>(nullable: true)
                 },
-                constraints: table => table.PrimaryKey("PK_Posts", x => x.Id));
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_Posts", x => x.Id);
+                });
         }
 
         protected override void Down(MigrationBuilder migrationBuilder)

Sieve.Sample/Migrations/ApplicationDbContextModelSnapshot.cs

@@ -0,0 +1,50 @@
+// <auto-generated />
+using System;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using Sieve.Sample.Entities;
+
+namespace Sieve.Sample.Migrations
+{
+    [DbContext(typeof(ApplicationDbContext))]
+    partial class ApplicationDbContextModelSnapshot : ModelSnapshot
+    {
+        protected override void BuildModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "3.1.14");
+
+            modelBuilder.Entity("Sieve.Sample.Entities.Post", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int?>("CategoryId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("CommentCount")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<DateTimeOffset>("DateCreated")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime>("DateLastViewed")
+                        .HasColumnType("datetime");
+
+                    b.Property<int>("LikeCount")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Title")
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("Posts");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

Sieve.Sample/Program.cs

@@ -1,7 +1,7 @@
 using Microsoft.AspNetCore;
 using Microsoft.AspNetCore.Hosting;
 
-namespace SieveTests
+namespace Sieve.Sample
 {
     public static class Program
     {

Sieve.Sample/Services/ApplicationSieveProcessor.cs

@@ -1,9 +1,9 @@
 using Microsoft.Extensions.Options;
 using Sieve.Models;
+using Sieve.Sample.Entities;
 using Sieve.Services;
-using SieveTests.Entities;
 
-namespace SieveTests.Services
+namespace Sieve.Sample.Services
 {
     public class ApplicationSieveProcessor : SieveProcessor
     {

Sieve.Sample/Services/SieveCustomFilterMethods.cs

@@ -1,8 +1,8 @@
 using System.Linq;
+using Sieve.Sample.Entities;
 using Sieve.Services;
-using SieveTests.Entities;
 
-namespace SieveTests.Services
+namespace Sieve.Sample.Services
 {
     public class SieveCustomFilterMethods : ISieveCustomFilterMethods
     {

Sieve.Sample/Services/SieveCustomSortMethods.cs

@@ -1,8 +1,8 @@
 using System.Linq;
+using Sieve.Sample.Entities;
 using Sieve.Services;
-using SieveTests.Entities;
 
-namespace SieveTests.Services
+namespace Sieve.Sample.Services
 {
     public class SieveCustomSortMethods : ISieveCustomSortMethods
     {

Sieve.Sample/Sieve.Sample.csproj

@@ -0,0 +1,20 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="3.1.14">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Relational" Version="3.1.14" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="3.1.14" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\SieveUnitTests\SieveUnitTests.csproj" />
+    <ProjectReference Include="..\Sieve\Sieve.csproj" />
+  </ItemGroup>
+
+</Project>

Sieve.Sample/Startup.cs

@@ -0,0 +1,60 @@
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using Sieve.Models;
+using Sieve.Sample.Entities;
+using Sieve.Sample.Services;
+using Sieve.Services;
+
+namespace Sieve.Sample
+{
+    public class Startup
+    {
+        public Startup(IConfiguration configuration)
+        {
+            Configuration = configuration;
+        }
+
+        public IConfiguration Configuration { get; }
+
+        public void ConfigureServices(IServiceCollection services)
+        {
+            services.AddMvc(opts =>
+            {
+                opts.EnableEndpointRouting = false;
+            });
+
+            services.AddDbContext<ApplicationDbContext>(options =>
+                options.UseSqlite("Data Source=.\\sieve.db"));
+
+            services.Configure<SieveOptions>(Configuration.GetSection("Sieve"));
+
+            services.AddScoped<ISieveCustomSortMethods, SieveCustomSortMethods>();
+            services.AddScoped<ISieveCustomFilterMethods, SieveCustomFilterMethods>();
+            services.AddScoped<ISieveProcessor, ApplicationSieveProcessor>();
+        }
+
+        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
+        {
+            PrepareDatabase(app);
+
+            if (env.IsDevelopment())
+            {
+                app.UseDeveloperExceptionPage();
+            }
+
+            app.UseMvc();
+        }
+
+        private static void PrepareDatabase(IApplicationBuilder app)
+        {
+            using var scope = app.ApplicationServices.CreateScope();
+            var dbContext = scope.ServiceProvider.GetRequiredService<ApplicationDbContext>();
+            dbContext.Database.EnsureDeleted();
+            dbContext.Database.Migrate();
+        }
+    }
+}

Sieve.sln

@@ -5,7 +5,7 @@ VisualStudioVersion = 15.0.27130.2027
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Sieve", "Sieve\Sieve.csproj", "{B32B8B33-94B0-40E3-8FE5-D54602222717}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "SieveTests", "SieveTests\SieveTests.csproj", "{8043D264-42A0-4275-97A1-46400C02E37E}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Sieve.Sample", "Sieve.Sample\Sieve.Sample.csproj", "{8043D264-42A0-4275-97A1-46400C02E37E}"
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "SieveUnitTests", "SieveUnitTests\SieveUnitTests.csproj", "{21C3082D-F40E-457F-BE2E-AA099E19E199}"
 EndProject

Sieve/Models/SieveModel.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations;
 using System.Linq;
 using System.Runtime.Serialization;
@@ -13,8 +14,16 @@ namespace Sieve.Models
         where TFilterTerm : IFilterTerm, new()
         where TSortTerm : ISortTerm, new()
     {
+        /// <summary>
+        /// Pattern used to split filters and sorts by comma.
+        /// </summary>
         private const string EscapedCommaPattern = @"(?<!($|[^\\])(\\\\)*?\\),\s*";
         
+        /// <summary>
+        /// Escaped comma e.g. used in filter filter string.
+        /// </summary>
+        private const string EscapedComma = @"\,";
+
         [DataMember]
         public string Filters { get; set; }
 
@@ -34,15 +43,20 @@ namespace Sieve.Models
                 var value = new List<TFilterTerm>();
                 foreach (var filter in Regex.Split(Filters, EscapedCommaPattern))
                 {
-                    if (string.IsNullOrWhiteSpace(filter)) continue;
+                    if (string.IsNullOrWhiteSpace(filter))
+                    {
+                        continue;
+                    }
+
+                    var filterValue = filter.Replace(EscapedComma, ",");
 
                     if (filter.StartsWith("("))
                     {
-                        var filterOpAndVal = filter.Substring(filter.LastIndexOf(")") + 1);
-                        var subfilters = filter.Replace(filterOpAndVal, "").Replace("(", "").Replace(")", "");
+                        var filterOpAndVal = filterValue[(filterValue.LastIndexOf(")", StringComparison.Ordinal) + 1)..];
+                        var subFilters = filterValue.Replace(filterOpAndVal, "").Replace("(", "").Replace(")", "");
                         var filterTerm = new TFilterTerm
                         {
-                            Filter = subfilters + filterOpAndVal
+                            Filter = subFilters + filterOpAndVal
                         };
                         value.Add(filterTerm);
                     }
@@ -50,7 +64,7 @@ namespace Sieve.Models
                     {
                         var filterTerm = new TFilterTerm
                         {
-                            Filter = filter
+                            Filter = filterValue
                         };
                         value.Add(filterTerm);
                     }
@@ -65,29 +79,28 @@ namespace Sieve.Models
 
         public List<TSortTerm> GetSortsParsed()
         {
-            if (Sorts != null)
-            {
-                var value = new List<TSortTerm>();
-                foreach (var sort in Regex.Split(Sorts, EscapedCommaPattern))
-                {
-                    if (string.IsNullOrWhiteSpace(sort)) continue;
-
-                    var sortTerm = new TSortTerm()
-                    {
-                        Sort = sort
-                    };
-                    if (!value.Any(s => s.Name == sortTerm.Name))
-                    {
-                        value.Add(sortTerm);
-                    }
-                }
-                return value;
-            }
-            else
+            if (Sorts == null)
             {
                 return null;
             }
 
+            var value = new List<TSortTerm>();
+            foreach (var sort in Regex.Split(Sorts, EscapedCommaPattern))
+            {
+                if (string.IsNullOrWhiteSpace(sort)) continue;
+
+                var sortTerm = new TSortTerm
+                {
+                    Sort = sort
+                };
+
+                if (value.All(s => s.Name != sortTerm.Name))
+                {
+                    value.Add(sortTerm);
+                }
+            }
+
+            return value;
         }
     }
 }

Sieve/Services/SieveProcessor.cs

@@ -14,40 +14,50 @@ namespace Sieve.Services
 {
     public class SieveProcessor : SieveProcessor<SieveModel, FilterTerm, SortTerm>, ISieveProcessor
     {
-        public SieveProcessor(IOptions<SieveOptions> options) : base(options)
+        public SieveProcessor(IOptions<SieveOptions> options)
+            : base(options)
         {
         }
 
-        public SieveProcessor(IOptions<SieveOptions> options, ISieveCustomSortMethods customSortMethods) : base(options, customSortMethods)
+        public SieveProcessor(IOptions<SieveOptions> options, ISieveCustomSortMethods customSortMethods)
+            : base(options, customSortMethods)
         {
         }
 
-        public SieveProcessor(IOptions<SieveOptions> options, ISieveCustomFilterMethods customFilterMethods) : base(options, customFilterMethods)
+        public SieveProcessor(IOptions<SieveOptions> options, ISieveCustomFilterMethods customFilterMethods)
+            : base(options, customFilterMethods)
         {
         }
 
-        public SieveProcessor(IOptions<SieveOptions> options, ISieveCustomSortMethods customSortMethods, ISieveCustomFilterMethods customFilterMethods) : base(options, customSortMethods, customFilterMethods)
+        public SieveProcessor(IOptions<SieveOptions> options, ISieveCustomSortMethods customSortMethods,
+            ISieveCustomFilterMethods customFilterMethods) : base(options, customSortMethods, customFilterMethods)
         {
         }
     }
 
-    public class SieveProcessor<TFilterTerm, TSortTerm> : SieveProcessor<SieveModel<TFilterTerm, TSortTerm>, TFilterTerm, TSortTerm>, ISieveProcessor<TFilterTerm, TSortTerm>
+    public class SieveProcessor<TFilterTerm, TSortTerm> :
+        SieveProcessor<SieveModel<TFilterTerm, TSortTerm>, TFilterTerm, TSortTerm>, ISieveProcessor<TFilterTerm, TSortTerm>
         where TFilterTerm : IFilterTerm, new()
         where TSortTerm : ISortTerm, new()
     {
-        public SieveProcessor(IOptions<SieveOptions> options) : base(options)
+        public SieveProcessor(IOptions<SieveOptions> options)
+            : base(options)
         {
         }
 
-        public SieveProcessor(IOptions<SieveOptions> options, ISieveCustomSortMethods customSortMethods) : base(options, customSortMethods)
+        public SieveProcessor(IOptions<SieveOptions> options, ISieveCustomSortMethods customSortMethods)
+            : base(options, customSortMethods)
         {
         }
 
-        public SieveProcessor(IOptions<SieveOptions> options, ISieveCustomFilterMethods customFilterMethods) : base(options, customFilterMethods)
+        public SieveProcessor(IOptions<SieveOptions> options, ISieveCustomFilterMethods customFilterMethods)
+            : base(options, customFilterMethods)
         {
         }
 
-        public SieveProcessor(IOptions<SieveOptions> options, ISieveCustomSortMethods customSortMethods, ISieveCustomFilterMethods customFilterMethods) : base(options, customSortMethods, customFilterMethods)
+        public SieveProcessor(IOptions<SieveOptions> options, ISieveCustomSortMethods customSortMethods,
+            ISieveCustomFilterMethods customFilterMethods)
+            : base(options, customSortMethods, customFilterMethods)
         {
         }
     }
@@ -57,17 +67,17 @@ namespace Sieve.Services
         where TFilterTerm : IFilterTerm, new()
         where TSortTerm : ISortTerm, new()
     {
-        private const string nullFilterValue = "null";
+        private const string NullFilterValue = "null";
         private readonly IOptions<SieveOptions> _options;
         private readonly ISieveCustomSortMethods _customSortMethods;
         private readonly ISieveCustomFilterMethods _customFilterMethods;
-        private readonly SievePropertyMapper mapper = new SievePropertyMapper();
+        private readonly SievePropertyMapper _mapper = new SievePropertyMapper();
 
         public SieveProcessor(IOptions<SieveOptions> options,
             ISieveCustomSortMethods customSortMethods,
             ISieveCustomFilterMethods customFilterMethods)
         {
-            mapper = MapProperties(mapper);
+            _mapper = MapProperties(_mapper);
             _options = options;
             _customSortMethods = customSortMethods;
             _customFilterMethods = customFilterMethods;
@@ -76,7 +86,7 @@ namespace Sieve.Services
         public SieveProcessor(IOptions<SieveOptions> options,
             ISieveCustomSortMethods customSortMethods)
         {
-            mapper = MapProperties(mapper);
+            _mapper = MapProperties(_mapper);
             _options = options;
             _customSortMethods = customSortMethods;
         }
@@ -84,14 +94,14 @@ namespace Sieve.Services
         public SieveProcessor(IOptions<SieveOptions> options,
             ISieveCustomFilterMethods customFilterMethods)
         {
-            mapper = MapProperties(mapper);
+            _mapper = MapProperties(_mapper);
             _options = options;
             _customFilterMethods = customFilterMethods;
         }
 
         public SieveProcessor(IOptions<SieveOptions> options)
         {
-            mapper = MapProperties(mapper);
+            _mapper = MapProperties(_mapper);
             _options = options;
         }
 
@@ -106,12 +116,8 @@ namespace Sieve.Services
         /// <param name="applySorting">Should the data be sorted? Defaults to true.</param>
         /// <param name="applyPagination">Should the data be paginated? Defaults to true.</param>
         /// <returns>Returns a transformed version of `source`</returns>
-        public IQueryable<TEntity> Apply<TEntity>(
-            TSieveModel model,
-            IQueryable<TEntity> source,
-            object[] dataForCustomMethods = null,
-            bool applyFiltering = true,
-            bool applySorting = true,
+        public IQueryable<TEntity> Apply<TEntity>(TSieveModel model, IQueryable<TEntity> source,
+            object[] dataForCustomMethods = null, bool applyFiltering = true, bool applySorting = true,
             bool applyPagination = true)
         {
             var result = source;
@@ -123,19 +129,16 @@ namespace Sieve.Services
 
             try
             {
-                // Filter
                 if (applyFiltering)
                 {
                     result = ApplyFiltering(model, result, dataForCustomMethods);
                 }
 
-                // Sort
                 if (applySorting)
                 {
                     result = ApplySorting(model, result, dataForCustomMethods);
                 }
 
-                // Paginate
                 if (applyPagination)
                 {
                     result = ApplyPagination(model, result);
@@ -145,25 +148,21 @@ namespace Sieve.Services
             }
             catch (Exception ex)
             {
-                if (_options.Value.ThrowExceptions)
-                {
-                    if (ex is SieveException)
-                    {
-                        throw;
-                    }
-
-                    throw new SieveException(ex.Message, ex);
-                }
-                else
+                if (!_options.Value.ThrowExceptions)
                 {
                     return result;
                 }
+
+                if (ex is SieveException)
+                {
+                    throw;
+                }
+
+                throw new SieveException(ex.Message, ex);
             }
         }
 
-        private IQueryable<TEntity> ApplyFiltering<TEntity>(
-            TSieveModel model,
-            IQueryable<TEntity> result,
+        private IQueryable<TEntity> ApplyFiltering<TEntity>(TSieveModel model, IQueryable<TEntity> result,
             object[] dataForCustomMethods = null)
         {
             if (model?.GetFiltersParsed() == null)
@@ -181,25 +180,20 @@ namespace Sieve.Services
                     var (fullPropertyName, property) = GetSieveProperty<TEntity>(false, true, filterTermName);
                     if (property != null)
                     {
-                        Expression propertyValue = parameter;
-                        Expression nullCheck = null;
-                        var names = fullPropertyName.Split('.');
-                        for (var i = 0; i < names.Length; i++)
+                        if (filterTerm.Values == null)
                         {
-                            propertyValue = Expression.PropertyOrField(propertyValue, names[i]);
-
-                            if (i != names.Length - 1 && propertyValue.Type.IsNullable())
-                            {
-                                nullCheck = GenerateFilterNullCheckExpression(propertyValue, nullCheck);
-                            }
+                            continue;
                         }
 
-                        if (filterTerm.Values == null) continue;
-
                         var converter = TypeDescriptor.GetConverter(property.PropertyType);
                         foreach (var filterTermValue in filterTerm.Values)
                         {
-                            var isFilterTermValueNull = filterTermValue.ToLower() == nullFilterValue;
+                            var (propertyValue, nullCheck) =
+                                GetPropertyValueAndNullCheckExpression(parameter, fullPropertyName);
+
+                            var isFilterTermValueNull =
+                                IsFilterTermValueNull(propertyValue, filterTerm, filterTermValue);
+
                             var filterValue = isFilterTermValueNull
                                 ? Expression.Constant(null, property.PropertyType)
                                 : ConvertStringValueToConstantExpression(filterTermValue, property, converter);
@@ -208,11 +202,11 @@ namespace Sieve.Services
                             {
                                 propertyValue = Expression.Call(propertyValue,
                                     typeof(string).GetMethods()
-                                    .First(m => m.Name == "ToUpper" && m.GetParameters().Length == 0));
+                                        .First(m => m.Name == "ToUpper" && m.GetParameters().Length == 0));
 
                                 filterValue = Expression.Call(filterValue,
                                     typeof(string).GetMethods()
-                                    .First(m => m.Name == "ToUpper" && m.GetParameters().Length == 0));
+                                        .First(m => m.Name == "ToUpper" && m.GetParameters().Length == 0));
                             }
 
                             var expression = GetExpression(filterTerm, filterValue, propertyValue);
@@ -222,60 +216,97 @@ namespace Sieve.Services
                                 expression = Expression.Not(expression);
                             }
 
-                            var filterValueNullCheck = !isFilterTermValueNull && propertyValue.Type.IsNullable()
-                                ? GenerateFilterNullCheckExpression(propertyValue, nullCheck)
-                                : nullCheck;
-
+                            var filterValueNullCheck = GetFilterValueNullCheck(parameter, fullPropertyName, isFilterTermValueNull);
                             if (filterValueNullCheck != null)
                             {
                                 expression = Expression.AndAlso(filterValueNullCheck, expression);
                             }
 
-                            if (innerExpression == null)
-                            {
-                                innerExpression = expression;
-                            }
-                            else
-                            {
-                                innerExpression = Expression.OrElse(innerExpression, expression);
-                            }
+                            innerExpression = innerExpression == null
+                                ? expression
+                                : Expression.OrElse(innerExpression, expression);
                         }
                     }
                     else
                     {
                         result = ApplyCustomMethod(result, filterTermName, _customFilterMethods,
-                            new object[] {
-                                            result,
-                                            filterTerm.Operator,
-                                            filterTerm.Values
-                            }, dataForCustomMethods);
-
+                            new object[] {result, filterTerm.Operator, filterTerm.Values}, dataForCustomMethods);
                     }
                 }
+
                 if (outerExpression == null)
                 {
                     outerExpression = innerExpression;
                     continue;
                 }
+
                 if (innerExpression == null)
                 {
                     continue;
                 }
+
                 outerExpression = Expression.AndAlso(outerExpression, innerExpression);
             }
+
             return outerExpression == null
                 ? result
                 : result.Where(Expression.Lambda<Func<TEntity, bool>>(outerExpression, parameter));
         }
 
-        private static Expression GenerateFilterNullCheckExpression(Expression propertyValue, Expression nullCheckExpression)
+        private static Expression GetFilterValueNullCheck(Expression parameter, string fullPropertyName,
+            bool isFilterTermValueNull)
+        {
+            var (propertyValue, nullCheck) = GetPropertyValueAndNullCheckExpression(parameter, fullPropertyName);
+
+            if (!isFilterTermValueNull && propertyValue.Type.IsNullable())
+            {
+                return GenerateFilterNullCheckExpression(propertyValue, nullCheck);
+            }
+
+            return nullCheck;
+        }
+
+        private static bool IsFilterTermValueNull(Expression propertyValue, TFilterTerm filterTerm,
+            string filterTermValue)
+        {
+            var isNotString = propertyValue.Type != typeof(string);
+
+            var isValidStringNullOperation = filterTerm.OperatorParsed == FilterOperator.Equals ||
+                                             filterTerm.OperatorParsed == FilterOperator.NotEquals;
+
+            return filterTermValue.ToLower() == NullFilterValue && (isNotString || isValidStringNullOperation);
+        }
+
+        private static (Expression propertyValue, Expression nullCheck) GetPropertyValueAndNullCheckExpression(
+            Expression parameter, string fullPropertyName)
+        {
+            var propertyValue = parameter;
+            Expression nullCheck = null;
+            var names = fullPropertyName.Split('.');
+            for (var i = 0; i < names.Length; i++)
+            {
+                propertyValue = Expression.PropertyOrField(propertyValue, names[i]);
+
+                if (i != names.Length - 1 && propertyValue.Type.IsNullable())
+                {
+                    nullCheck = GenerateFilterNullCheckExpression(propertyValue, nullCheck);
+                }
+            }
+
+            return (propertyValue, nullCheck);
+        }
+
+        private static Expression GenerateFilterNullCheckExpression(Expression propertyValue,
+            Expression nullCheckExpression)
         {
             return nullCheckExpression == null
                 ? Expression.NotEqual(propertyValue, Expression.Default(propertyValue.Type))
-                : Expression.AndAlso(nullCheckExpression, Expression.NotEqual(propertyValue, Expression.Default(propertyValue.Type)));
+                : Expression.AndAlso(nullCheckExpression,
+                    Expression.NotEqual(propertyValue, Expression.Default(propertyValue.Type)));
         }
 
-        private Expression ConvertStringValueToConstantExpression(string value, PropertyInfo property, TypeConverter converter)
+        private static Expression ConvertStringValueToConstantExpression(string value, PropertyInfo property,
+            TypeConverter converter)
         {
             dynamic constantVal = converter.CanConvertFrom(typeof(string))
                 ? converter.ConvertFrom(value)
@@ -286,47 +317,34 @@ namespace Sieve.Services
 
         private static Expression GetExpression(TFilterTerm filterTerm, dynamic filterValue, dynamic propertyValue)
         {
-            switch (filterTerm.OperatorParsed)
+            return filterTerm.OperatorParsed switch
             {
-                case FilterOperator.Equals:
-                    return Expression.Equal(propertyValue, filterValue);
-                case FilterOperator.NotEquals:
-                    return Expression.NotEqual(propertyValue, filterValue);
-                case FilterOperator.GreaterThan:
-                    return Expression.GreaterThan(propertyValue, filterValue);
-                case FilterOperator.LessThan:
-                    return Expression.LessThan(propertyValue, filterValue);
-                case FilterOperator.GreaterThanOrEqualTo:
-                    return Expression.GreaterThanOrEqual(propertyValue, filterValue);
-                case FilterOperator.LessThanOrEqualTo:
-                    return Expression.LessThanOrEqual(propertyValue, filterValue);
-                case FilterOperator.Contains:
-                    return Expression.Call(propertyValue,
-                        typeof(string).GetMethods()
-                        .First(m => m.Name == "Contains" && m.GetParameters().Length == 1),
-                        filterValue);
-                case FilterOperator.StartsWith:
-                    return Expression.Call(propertyValue,
-                        typeof(string).GetMethods()
-                        .First(m => m.Name == "StartsWith" && m.GetParameters().Length == 1),
-                        filterValue);
-                default:
-                    return Expression.Equal(propertyValue, filterValue);
-            }
+                FilterOperator.Equals => Expression.Equal(propertyValue, filterValue),
+                FilterOperator.NotEquals => Expression.NotEqual(propertyValue, filterValue),
+                FilterOperator.GreaterThan => Expression.GreaterThan(propertyValue, filterValue),
+                FilterOperator.LessThan => Expression.LessThan(propertyValue, filterValue),
+                FilterOperator.GreaterThanOrEqualTo => Expression.GreaterThanOrEqual(propertyValue, filterValue),
+                FilterOperator.LessThanOrEqualTo => Expression.LessThanOrEqual(propertyValue, filterValue),
+                FilterOperator.Contains => Expression.Call(propertyValue,
+                    typeof(string).GetMethods().First(m => m.Name == "Contains" && m.GetParameters().Length == 1),
+                    filterValue),
+                FilterOperator.StartsWith => Expression.Call(propertyValue,
+                    typeof(string).GetMethods().First(m => m.Name == "StartsWith" && m.GetParameters().Length == 1),
+                    filterValue),
+                _ => Expression.Equal(propertyValue, filterValue)
+            };
         }
 
         // Workaround to ensure that the filter value gets passed as a parameter in generated SQL from EF Core
         // See https://github.com/aspnet/EntityFrameworkCore/issues/3361
         // Expression.Constant passed the target type to allow Nullable comparison
         // See http://bradwilson.typepad.com/blog/2008/07/creating-nullab.html
-        private Expression GetClosureOverConstant<T>(T constant, Type targetType)
+        private static Expression GetClosureOverConstant<T>(T constant, Type targetType)
         {
             return Expression.Constant(constant, targetType);
         }
 
-        private IQueryable<TEntity> ApplySorting<TEntity>(
-            TSieveModel model,
-            IQueryable<TEntity> result,
+        private IQueryable<TEntity> ApplySorting<TEntity>(TSieveModel model, IQueryable<TEntity> result,
             object[] dataForCustomMethods = null)
         {
             if (model?.GetSortsParsed() == null)
@@ -346,33 +364,29 @@ namespace Sieve.Services
                 else
                 {
                     result = ApplyCustomMethod(result, sortTerm.Name, _customSortMethods,
-                        new object[]
-                        {
-                        result,
-                        useThenBy,
-                        sortTerm.Descending
-                        }, dataForCustomMethods);
+                        new object[] {result, useThenBy, sortTerm.Descending}, dataForCustomMethods);
                 }
+
                 useThenBy = true;
             }
 
             return result;
         }
 
-        private IQueryable<TEntity> ApplyPagination<TEntity>(
-            TSieveModel model,
-            IQueryable<TEntity> result)
+        private IQueryable<TEntity> ApplyPagination<TEntity>(TSieveModel model, IQueryable<TEntity> result)
         {
             var page = model?.Page ?? 1;
             var pageSize = model?.PageSize ?? _options.Value.DefaultPageSize;
             var maxPageSize = _options.Value.MaxPageSize > 0 ? _options.Value.MaxPageSize : pageSize;
 
-            if (pageSize > 0)
+            if (pageSize <= 0)
             {
-                result = result.Skip((page - 1) * pageSize);
-                result = result.Take(Math.Min(pageSize, maxPageSize));
+                return result;
             }
 
+            result = result.Skip((page - 1) * pageSize);
+            result = result.Take(Math.Min(pageSize, maxPageSize));
+
             return result;
         }
 
@@ -381,51 +395,52 @@ namespace Sieve.Services
             return mapper;
         }
 
-        private (string, PropertyInfo) GetSieveProperty<TEntity>(
-            bool canSortRequired,
-            bool canFilterRequired,
+        private (string, PropertyInfo) GetSieveProperty<TEntity>(bool canSortRequired, bool canFilterRequired,
             string name)
         {
-            var property = mapper.FindProperty<TEntity>(canSortRequired, canFilterRequired, name, _options.Value.CaseSensitive);
-            if (property.Item1 == null)
+            var property = _mapper.FindProperty<TEntity>(canSortRequired, canFilterRequired, name,
+                _options.Value.CaseSensitive);
+            if (property.Item1 != null)
             {
-                var prop = FindPropertyBySieveAttribute<TEntity>(canSortRequired, canFilterRequired, name, _options.Value.CaseSensitive);
-                return (prop?.Name, prop);
+                return property;
             }
-            return property;
 
+            var prop = FindPropertyBySieveAttribute<TEntity>(canSortRequired, canFilterRequired, name,
+                _options.Value.CaseSensitive);
+            return (prop?.Name, prop);
         }
 
-        private PropertyInfo FindPropertyBySieveAttribute<TEntity>(
-            bool canSortRequired,
-            bool canFilterRequired,
-            string name,
-            bool isCaseSensitive)
+        private static PropertyInfo FindPropertyBySieveAttribute<TEntity>(bool canSortRequired, bool canFilterRequired,
+            string name, bool isCaseSensitive)
         {
-            return Array.Find(typeof(TEntity).GetProperties(), p =>
-            {
-                return p.GetCustomAttribute(typeof(SieveAttribute)) is SieveAttribute sieveAttribute
-                && (!canSortRequired || sieveAttribute.CanSort)
-                && (!canFilterRequired || sieveAttribute.CanFilter)
-                && (sieveAttribute.Name ?? p.Name).Equals(name, isCaseSensitive ? StringComparison.Ordinal : StringComparison.OrdinalIgnoreCase);
-            });
+            return Array.Find(typeof(TEntity).GetProperties(),
+                p => p.GetCustomAttribute(typeof(SieveAttribute)) is SieveAttribute SieveAttribute
+                     && (!canSortRequired || SieveAttribute.CanSort)
+                     && (!canFilterRequired || SieveAttribute.CanFilter)
+                     && (SieveAttribute.Name ?? p.Name).Equals(name,
+                         isCaseSensitive ? StringComparison.Ordinal : StringComparison.OrdinalIgnoreCase));
         }
 
-        private IQueryable<TEntity> ApplyCustomMethod<TEntity>(IQueryable<TEntity> result, string name, object parent, object[] parameters, object[] optionalParameters = null)
+        private IQueryable<TEntity> ApplyCustomMethod<TEntity>(IQueryable<TEntity> result, string name, object parent,
+            object[] parameters, object[] optionalParameters = null)
         {
             var customMethod = parent?.GetType()
                 .GetMethodExt(name,
-                _options.Value.CaseSensitive ? BindingFlags.Default : BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.Instance,
-                typeof(IQueryable<TEntity>));
+                    _options.Value.CaseSensitive
+                        ? BindingFlags.Default
+                        : BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.Instance,
+                    typeof(IQueryable<TEntity>));
 
 
             if (customMethod == null)
             {
                 // Find generic methods `public IQueryable<T> Filter<T>(IQueryable<T> source, ...)`
                 var genericCustomMethod = parent?.GetType()
-                .GetMethodExt(name,
-                _options.Value.CaseSensitive ? BindingFlags.Default : BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.Instance,
-                typeof(IQueryable<>));
+                    .GetMethodExt(name,
+                        _options.Value.CaseSensitive
+                            ? BindingFlags.Default
+                            : BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.Instance,
+                        typeof(IQueryable<>));
 
                 if (genericCustomMethod != null &&
                     genericCustomMethod.ReturnType.IsGenericType &&
@@ -433,7 +448,8 @@ namespace Sieve.Services
                 {
                     var genericBaseType = genericCustomMethod.ReturnType.GenericTypeArguments[0];
                     var constraints = genericBaseType.GetGenericParameterConstraints();
-                    if (constraints == null || constraints.Length == 0 || constraints.All((t) => t.IsAssignableFrom(typeof(TEntity))))
+                    if (constraints == null || constraints.Length == 0 ||
+                        constraints.All((t) => t.IsAssignableFrom(typeof(TEntity))))
                     {
                         customMethod = genericCustomMethod.MakeGenericMethod(typeof(TEntity));
                     }
@@ -462,40 +478,34 @@ namespace Sieve.Services
             }
             else
             {
-                var incompatibleCustomMethods = parent?
-                                                    .GetType()
-                                                    .GetMethods
-                                                    (
-                                                        _options.Value.CaseSensitive
-                                                            ? BindingFlags.Default
-                                                            : BindingFlags.IgnoreCase | BindingFlags.Public |
-                                                              BindingFlags.Instance
-                                                    )
-                                                    .Where(method => string.Equals(method.Name, name,
-                                                        _options.Value.CaseSensitive
-                                                            ? StringComparison.InvariantCulture
-                                                            : StringComparison.InvariantCultureIgnoreCase))
-                                                    .ToList()
-                                                ??
-                                                new List<MethodInfo>();
+                var incompatibleCustomMethods =
+                    parent?
+                        .GetType()
+                        .GetMethods(_options.Value.CaseSensitive
+                            ? BindingFlags.Default
+                            : BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.Instance)
+                        .Where(method => string.Equals(method.Name, name,
+                            _options.Value.CaseSensitive
+                                ? StringComparison.InvariantCulture
+                                : StringComparison.InvariantCultureIgnoreCase))
+                        .ToList()
+                    ?? new List<MethodInfo>();
 
-                if (incompatibleCustomMethods.Any())
-                {
-                    var incompatibles =
-                        from incompatibleCustomMethod in incompatibleCustomMethods
-                        let expected = typeof(IQueryable<TEntity>)
-                        let actual = incompatibleCustomMethod.ReturnType
-                        select new SieveIncompatibleMethodException(name, expected, actual,
-                            $"{name} failed. Expected a custom method for type {expected} but only found for type {actual}");
-
-                    var aggregate = new AggregateException(incompatibles);
-
-                    throw new SieveIncompatibleMethodException(aggregate.Message, aggregate);
-                }
-                else
+                if (!incompatibleCustomMethods.Any())
                 {
                     throw new SieveMethodNotFoundException(name, $"{name} not found.");
                 }
+
+                var incompatibles =
+                    from incompatibleCustomMethod in incompatibleCustomMethods
+                    let expected = typeof(IQueryable<TEntity>)
+                    let actual = incompatibleCustomMethod.ReturnType
+                    select new SieveIncompatibleMethodException(name, expected, actual,
+                        $"{name} failed. Expected a custom method for type {expected} but only found for type {actual}");
+
+                var aggregate = new AggregateException(incompatibles);
+
+                throw new SieveIncompatibleMethodException(aggregate.Message, aggregate);
             }
 
             return result;

Sieve/Sieve.csproj

@@ -1,22 +1,25 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
-    <Version>2.3.3</Version>
-    <Description>Sieve is a simple, clean, and extensible framework for .NET Core that adds sorting, filtering, and pagination functionality out of the box. Most common use case would be for serving ASP.NET Core GET queries. Documentation available on GitHub: https://github.com/Biarity/Sieve/
-</Description>
-    <Copyright>Copyright 2018</Copyright>
-    <PackageLicenseUrl>https://github.com/Biarity/Sieve/blob/master/LICENSE</PackageLicenseUrl>
+    <TargetFramework>netstandard2.1</TargetFramework>   
+    <Description>Sieve is a simple, clean, and extensible framework for .NET Core that adds sorting, filtering, and pagination functionality out of the box. Most common use case would be for serving ASP.NET Core GET queries. Documentation available on GitHub: https://github.com/Biarity/Sieve/</Description>
+    <Authors>2018 Biarity, 2021 Kevin Sommer</Authors>
+
+    <PackageTags>Filter;Sort;Page;Paging;</PackageTags>
+    <PackageIcon>icon.png</PackageIcon>
     <PackageProjectUrl>https://github.com/Biarity/Sieve</PackageProjectUrl>
-    <PackageIconUrl>https://emojipedia-us.s3.amazonaws.com/thumbs/240/twitter/120/alembic_2697.png</PackageIconUrl>
-    <RepositoryUrl></RepositoryUrl>
-    <PackageReleaseNotes>Only Skip when pageSize &gt; 0 (#63)
-Added support for generic filter and sort methods (#60)
-Don't process when filterTerm.Values is null (#59)
-</PackageReleaseNotes>
-    <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
+    <PackageLicenseExpression>Apache-2.0</PackageLicenseExpression>
     <PackageRequireLicenseAcceptance>true</PackageRequireLicenseAcceptance>
-    <Authors>Biarity</Authors>
+
+    <RepositoryUrl>https://github.com/Biarity/Sieve</RepositoryUrl>
+    <RepositoryType>git</RepositoryType>
+
+    <!-- Declare that the Repository URL can be published to NuSpec -->
+    <PublishRepositoryUrl>true</PublishRepositoryUrl>
+    <!-- Embed source files that are not tracked by the source control manager to the PDB -->
+    <EmbedUntrackedSources>true</EmbedUntrackedSources>
+    <!-- Include PDB in the built .nupkg -->
+    <AllowedOutputExtensionsInPackageBuildOutputFolder>$(AllowedOutputExtensionsInPackageBuildOutputFolder);.pdb</AllowedOutputExtensionsInPackageBuildOutputFolder>
   </PropertyGroup>
 
   <ItemGroup>

SieveTests/Migrations/20180127005347_Init.Designer.cs

@@ -1,44 +0,0 @@
-// <auto-generated />
-using Microsoft.EntityFrameworkCore;
-using Microsoft.EntityFrameworkCore.Infrastructure;
-using Microsoft.EntityFrameworkCore.Metadata;
-using Microsoft.EntityFrameworkCore.Migrations;
-using Microsoft.EntityFrameworkCore.Storage;
-using Microsoft.EntityFrameworkCore.Storage.Internal;
-using SieveTests.Entities;
-using System;
-
-namespace SieveTests.Migrations
-{
-    [DbContext(typeof(ApplicationDbContext))]
-    [Migration("20180127005347_Init")]
-    partial class Init
-    {
-        protected override void BuildTargetModel(ModelBuilder modelBuilder)
-        {
-#pragma warning disable 612, 618
-            modelBuilder
-                .HasAnnotation("ProductVersion", "2.0.1-rtm-125")
-                .HasAnnotation("SqlServer:ValueGenerationStrategy", SqlServerValueGenerationStrategy.IdentityColumn);
-
-            modelBuilder.Entity("SieveTests.Entities.Post", b =>
-                {
-                    b.Property<int>("Id")
-                        .ValueGeneratedOnAdd();
-
-                    b.Property<int>("CommentCount");
-
-                    b.Property<DateTimeOffset>("DateCreated");
-
-                    b.Property<int>("LikeCount");
-
-                    b.Property<string>("Title");
-
-                    b.HasKey("Id");
-
-                    b.ToTable("Posts");
-                });
-#pragma warning restore 612, 618
-        }
-    }
-}

SieveTests/Migrations/20180522013323_AddDateLastViewedColumn.Designer.cs

@@ -1,47 +0,0 @@
-// <auto-generated />
-using Microsoft.EntityFrameworkCore;
-using Microsoft.EntityFrameworkCore.Infrastructure;
-using Microsoft.EntityFrameworkCore.Metadata;
-using Microsoft.EntityFrameworkCore.Migrations;
-using Microsoft.EntityFrameworkCore.Storage;
-using Microsoft.EntityFrameworkCore.Storage.Internal;
-using SieveTests.Entities;
-using System;
-
-namespace SieveTests.Migrations
-{
-    [DbContext(typeof(ApplicationDbContext))]
-    [Migration("20180522013323_AddDateLastViewedColumn")]
-    partial class AddDateLastViewedColumn
-    {
-        protected override void BuildTargetModel(ModelBuilder modelBuilder)
-        {
-#pragma warning disable 612, 618
-            modelBuilder
-                .HasAnnotation("ProductVersion", "2.0.1-rtm-125")
-                .HasAnnotation("SqlServer:ValueGenerationStrategy", SqlServerValueGenerationStrategy.IdentityColumn);
-
-            modelBuilder.Entity("SieveTests.Entities.Post", b =>
-                {
-                    b.Property<int>("Id")
-                        .ValueGeneratedOnAdd();
-
-                    b.Property<int>("CommentCount");
-
-                    b.Property<DateTimeOffset>("DateCreated");
-
-                    b.Property<DateTime>("DateLastViewed")
-                        .HasColumnType("datetime");
-
-                    b.Property<int>("LikeCount");
-
-                    b.Property<string>("Title");
-
-                    b.HasKey("Id");
-
-                    b.ToTable("Posts");
-                });
-#pragma warning restore 612, 618
-        }
-    }
-}

SieveTests/Migrations/20180522013323_AddDateLastViewedColumn.cs

@@ -1,25 +0,0 @@
-using System;
-using Microsoft.EntityFrameworkCore.Migrations;
-
-namespace SieveTests.Migrations
-{
-    public partial class AddDateLastViewedColumn : Migration
-    {
-        protected override void Up(MigrationBuilder migrationBuilder)
-        {
-            migrationBuilder.AddColumn<DateTime>(
-                name: "DateLastViewed",
-                table: "Posts",
-                type: "datetime",
-                nullable: false,
-                defaultValue: new DateTime(1, 1, 1, 0, 0, 0, 0, DateTimeKind.Unspecified));
-        }
-
-        protected override void Down(MigrationBuilder migrationBuilder)
-        {
-            migrationBuilder.DropColumn(
-                name: "DateLastViewed",
-                table: "Posts");
-        }
-    }
-}

SieveTests/Migrations/ApplicationDbContextModelSnapshot.cs

@@ -1,48 +0,0 @@
-// <auto-generated />
-using Microsoft.EntityFrameworkCore;
-using Microsoft.EntityFrameworkCore.Infrastructure;
-using Microsoft.EntityFrameworkCore.Metadata;
-using Microsoft.EntityFrameworkCore.Migrations;
-using Microsoft.EntityFrameworkCore.Storage;
-using Microsoft.EntityFrameworkCore.Storage.Internal;
-using SieveTests.Entities;
-using System;
-
-namespace SieveTests.Migrations
-{
-    [DbContext(typeof(ApplicationDbContext))]
-    partial class ApplicationDbContextModelSnapshot : ModelSnapshot
-    {
-        protected override void BuildModel(ModelBuilder modelBuilder)
-        {
-#pragma warning disable 612, 618
-            modelBuilder
-                .HasAnnotation("ProductVersion", "2.0.1-rtm-125")
-                .HasAnnotation("SqlServer:ValueGenerationStrategy", SqlServerValueGenerationStrategy.IdentityColumn);
-
-            modelBuilder.Entity("SieveTests.Entities.Post", b =>
-                {
-                    b.Property<int>("Id")
-                        .ValueGeneratedOnAdd();
-
-                    b.Property<int>("CommentCount");
-
-                    b.Property<DateTimeOffset>("DateCreated");
-
-                    b.Property<DateTime>("DateLastViewed")
-                        .HasColumnType("datetime");
-
-                    b.Property<int>("LikeCount");
-
-                    b.Property<int?>("CategoryId");
-
-                    b.Property<string>("Title");
-
-                    b.HasKey("Id");
-
-                    b.ToTable("Posts");
-                });
-#pragma warning restore 612, 618
-        }
-    }
-}

SieveTests/SieveTests.csproj

@@ -1,29 +0,0 @@
-<Project Sdk="Microsoft.NET.Sdk.Web">
-
-  <PropertyGroup>
-    <TargetFramework>netcoreapp2.0</TargetFramework>
-  </PropertyGroup>
-
-  <ItemGroup>
-    <Compile Remove="Migrations\20180127005211_Itit.cs" />
-    <Compile Remove="Migrations\20180127005211_Itit.Designer.cs" />
-  </ItemGroup>
-
-  <ItemGroup>
-    <Folder Include="wwwroot\" />
-  </ItemGroup>
-
-  <ItemGroup>
-    <PackageReference Include="Microsoft.AspNetCore.All" Version="2.0.9" />
-  </ItemGroup>
-
-  <ItemGroup>
-    <DotNetCliToolReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Tools" Version="2.0.1" />
-  </ItemGroup>
-
-  <ItemGroup>
-    <ProjectReference Include="..\SieveUnitTests\SieveUnitTests.csproj" />
-    <ProjectReference Include="..\Sieve\Sieve.csproj" />
-  </ItemGroup>
-
-</Project>

SieveTests/Startup.cs

@@ -1,67 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Diagnostics;
-using System.Linq;
-using Microsoft.AspNetCore.Builder;
-using Microsoft.AspNetCore.Hosting;
-using Microsoft.AspNetCore.Http;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Configuration;
-using Microsoft.Extensions.DependencyInjection;
-using Sieve.Models;
-using Sieve.Services;
-using SieveTests.Entities;
-using SieveTests.Services;
-
-namespace SieveTests
-{
-    public class Startup
-    {
-        public Startup(IConfiguration configuration)
-        {
-            Configuration = configuration;
-        }
-
-        public IConfiguration Configuration { get; }
-
-        // This method gets called by the runtime. Use this method to add services to the container.
-        public void ConfigureServices(IServiceCollection services)
-        {
-            services.AddMvc();
-
-            services.AddDbContext<ApplicationDbContext>(options =>
-                options.UseSqlServer(Configuration.GetConnectionString("TestSqlServer")));
-
-            services.Configure<SieveOptions>(Configuration.GetSection("Sieve"));
-
-            services.AddScoped<ISieveCustomSortMethods, SieveCustomSortMethods>();
-            services.AddScoped<ISieveCustomFilterMethods, SieveCustomFilterMethods>();
-            services.AddScoped<ISieveProcessor, ApplicationSieveProcessor>();
-        }
-
-        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
-        public void Configure(IApplicationBuilder app, IHostingEnvironment env)
-        {
-            // TIME MEASUREMENT
-            var times = new List<long>();
-            app.Use(async (context, next) =>
-            {
-                var sw = new Stopwatch();
-                sw.Start();
-                await next.Invoke();
-                sw.Stop();
-                times.Add(sw.ElapsedMilliseconds);
-                var text = $"AVG: {(int)times.Average()}ms; AT {sw.ElapsedMilliseconds}; COUNT: {times.Count()}";
-                Console.WriteLine(text);
-                await context.Response.WriteAsync($"<!-- {text} -->");
-            });
-
-            if (env.IsDevelopment())
-            {
-                app.UseDeveloperExceptionPage();
-            }
-
-            app.UseMvc();
-        }
-    }
-}

SieveUnitTests/Entities/Comment.cs

@@ -7,5 +7,8 @@ namespace SieveUnitTests.Entities
     {
         [Sieve(CanFilter = true)]
         public string Text { get; set; }
+        
+        [Sieve(CanFilter = true)]
+        public string Author { get; set; }
     }
 }

SieveUnitTests/General.cs

@@ -1,32 +1,34 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using Microsoft.VisualStudio.TestTools.UnitTesting;
 using Sieve.Exceptions;
 using Sieve.Models;
 using Sieve.Services;
-using SieveUnitTests.Abstractions.Entity;
 using SieveUnitTests.Entities;
 using SieveUnitTests.Services;
+using Xunit;
+using Xunit.Abstractions;
 
 namespace SieveUnitTests
 {
-    [TestClass]
     public class General
     {
+        private readonly ITestOutputHelper _testOutputHelper;
         private readonly SieveProcessor _processor;
         private readonly IQueryable<Post> _posts;
         private readonly IQueryable<Comment> _comments;
 
-        public General()
+        public General(ITestOutputHelper testOutputHelper)
         {
+            _testOutputHelper = testOutputHelper;
             _processor = new ApplicationSieveProcessor(new SieveOptionsAccessor(),
                 new SieveCustomSortMethods(),
                 new SieveCustomFilterMethods());
 
             _posts = new List<Post>
             {
-                new Post() {
+                new Post
+                {
                     Id = 0,
                     Title = "A",
                     LikeCount = 100,
@@ -35,7 +37,8 @@ namespace SieveUnitTests
                     TopComment = new Comment { Id = 0, Text = "A1" },
                     FeaturedComment = new Comment { Id = 4, Text = "A2" }
                 },
-                new Post() {
+                new Post
+                {
                     Id = 1,
                     Title = "B",
                     LikeCount = 50,
@@ -44,7 +47,8 @@ namespace SieveUnitTests
                     TopComment = new Comment { Id = 3, Text = "B1" },
                     FeaturedComment = new Comment { Id = 5, Text = "B2" }
                 },
-                new Post() {
+                new Post
+                {
                     Id = 2,
                     Title = "C",
                     LikeCount = 0,
@@ -52,7 +56,8 @@ namespace SieveUnitTests
                     TopComment = new Comment { Id = 2, Text = "C1" },
                     FeaturedComment = new Comment { Id = 6, Text = "C2" }
                 },
-                new Post() {
+                new Post
+                {
                     Id = 3,
                     Title = "D",
                     LikeCount = 3,
@@ -65,281 +70,301 @@ namespace SieveUnitTests
 
             _comments = new List<Comment>
             {
-                new Comment() {
+                new Comment
+                {
                     Id = 0,
                     DateCreated = DateTimeOffset.UtcNow.AddDays(-20),
                     Text = "This is an old comment."
                 },
-                new Comment() {
+                new Comment
+                {
                     Id = 1,
                     DateCreated = DateTimeOffset.UtcNow.AddDays(-1),
                     Text = "This is a fairly new comment."
                 },
-                new Comment() {
+                new Comment
+                {
                     Id = 2,
                     DateCreated = DateTimeOffset.UtcNow,
-                    Text = "This is a brand new comment. (Text in braces)"
+                    Text = "This is a brand new comment. (Text in braces, comma separated)"
                 },
             }.AsQueryable();
         }
 
-        [TestMethod]
+        [Fact]
         public void ContainsCanBeCaseInsensitive()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "Title@=*a"
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.AreEqual(result.First().Id, 0);
-            Assert.IsTrue(result.Count() == 1);
+            Assert.Equal(0, result.First().Id);
+            Assert.True(result.Count() == 1);
         }
 
-        [TestMethod]
+        [Fact]
         public void NotEqualsCanBeCaseInsensitive()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "Title!=*a"
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.AreEqual(result.First().Id, 1);
-            Assert.IsTrue(result.Count() == 3);
+            Assert.Equal(1, result.First().Id);
+            Assert.True(result.Count() == 3);
         }
 
-        [TestMethod]
+        [Fact]
         public void ContainsIsCaseSensitive()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "Title@=a",
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.IsTrue(result.Count() == 0);
+            Assert.True(!result.Any());
         }
 
-        [TestMethod]
+        [Fact]
         public void NotContainsWorks()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "Title!@=D",
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.IsTrue(result.Count() == 3);
+            Assert.True(result.Count() == 3);
         }
 
-        [TestMethod]
+        [Fact]
         public void CanFilterBools()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "IsDraft==false"
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.IsTrue(result.Count() == 2);
+            Assert.True(result.Count() == 2);
         }
 
-        [TestMethod]
+        [Fact]
         public void CanSortBools()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Sorts = "-IsDraft"
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.AreEqual(result.First().Id, 0);
+            Assert.Equal(0, result.First().Id);
         }
 
-        [TestMethod]
+        [Fact]
         public void CanFilterNullableInts()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "CategoryId==1"
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.IsTrue(result.Count() == 2);
+            Assert.True(result.Count() == 2);
         }
         
-        [TestMethod]
+        [Theory]
+        [InlineData(@"Text@=*\,")]
+        [InlineData(@"Text@=*\, ")]
+        [InlineData(@"Text@=*braces\,")]
+        [InlineData(@"Text@=*braces\, comma")]
+        public void CanFilterWithEscapedComma(string filter)
+        {
+            var model = new SieveModel
+            {
+                Filters = filter
+            };
+
+            var result = _processor.Apply(model, _comments);
+
+            Assert.True(result.Count() == 1);
+        }
+
+        [Fact]
         public void EqualsDoesntFailWithNonStringTypes()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "LikeCount==50",
             };
 
-            Console.WriteLine(model.GetFiltersParsed()[0].Values);
-            Console.WriteLine(model.GetFiltersParsed()[0].Operator);
-            Console.WriteLine(model.GetFiltersParsed()[0].OperatorParsed);
+            _testOutputHelper.WriteLine(model.GetFiltersParsed()[0].Values.ToString());
+            _testOutputHelper.WriteLine(model.GetFiltersParsed()[0].Operator);
+            _testOutputHelper.WriteLine(model.GetFiltersParsed()[0].OperatorParsed.ToString());
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.AreEqual(result.First().Id, 1);
-            Assert.IsTrue(result.Count() == 1);
+            Assert.Equal(1, result.First().Id);
+            Assert.True(result.Count() == 1);
         }
 
-        [TestMethod]
+        [Fact]
         public void CustomFiltersWork()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "Isnew",
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.IsFalse(result.Any(p => p.Id == 0));
-            Assert.IsTrue(result.Count() == 3);
+            Assert.False(result.Any(p => p.Id == 0));
+            Assert.True(result.Count() == 3);
         }
 
-        [TestMethod]
+        [Fact]
         public void CustomGenericFiltersWork()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "Latest",
             };
 
             var result = _processor.Apply(model, _comments);
 
-            Assert.IsFalse(result.Any(p => p.Id == 0));
-            Assert.IsTrue(result.Count() == 2);
+            Assert.False(result.Any(p => p.Id == 0));
+            Assert.True(result.Count() == 2);
         }
 
-        [TestMethod]
+        [Fact]
         public void CustomFiltersWithOperatorsWork()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "HasInTitle==A",
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.IsTrue(result.Any(p => p.Id == 0));
-            Assert.IsTrue(result.Count() == 1);
+            Assert.True(result.Any(p => p.Id == 0));
+            Assert.True(result.Count() == 1);
         }
 
-        [TestMethod]
+        [Fact]
         public void CustomFiltersMixedWithUsualWork1()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "Isnew,CategoryId==2",
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.IsTrue(result.Any(p => p.Id == 3));
-            Assert.IsTrue(result.Count() == 1);
+            Assert.True(result.Any(p => p.Id == 3));
+            Assert.True(result.Count() == 1);
         }
 
-        [TestMethod]
+        [Fact]
         public void CustomFiltersMixedWithUsualWork2()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "CategoryId==2,Isnew",
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.IsTrue(result.Any(p => p.Id == 3));
-            Assert.IsTrue(result.Count() == 1);
+            Assert.True(result.Any(p => p.Id == 3));
+            Assert.True(result.Count() == 1);
         }
 
-        [TestMethod]
+        [Fact]
         public void CustomFiltersOnDifferentSourcesCanShareName()
         {
-            var postModel = new SieveModel()
+            var postModel = new SieveModel
             {
                 Filters = "CategoryId==2,Isnew",
             };
 
             var postResult = _processor.Apply(postModel, _posts);
 
-            Assert.IsTrue(postResult.Any(p => p.Id == 3));
-            Assert.AreEqual(1, postResult.Count());
+            Assert.True(postResult.Any(p => p.Id == 3));
+            Assert.Equal(1, postResult.Count());
 
-            var commentModel = new SieveModel()
+            var commentModel = new SieveModel
             {
                 Filters = "Isnew",
             };
 
             var commentResult = _processor.Apply(commentModel, _comments);
 
-            Assert.IsTrue(commentResult.Any(c => c.Id == 2));
-            Assert.AreEqual(2, commentResult.Count());
+            Assert.True(commentResult.Any(c => c.Id == 2));
+            Assert.Equal(2, commentResult.Count());
         }
 
-        [TestMethod]
+        [Fact]
         public void CustomSortsWork()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Sorts = "Popularity",
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.IsFalse(result.First().Id == 0);
+            Assert.False(result.First().Id == 0);
         }
 
-        [TestMethod]
+        [Fact]
         public void CustomGenericSortsWork()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Sorts = "Oldest",
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.IsTrue(result.Last().Id == 0);
+            Assert.True(result.Last().Id == 0);
         }
 
-        [TestMethod]
+        [Fact]
         public void MethodNotFoundExceptionWork()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "does not exist",
             };
 
-            Assert.ThrowsException<SieveMethodNotFoundException>(() => _processor.Apply(model, _posts));
+            Assert.Throws<SieveMethodNotFoundException>(() => _processor.Apply(model, _posts));
         }
 
-        [TestMethod]
+        [Fact]
         public void IncompatibleMethodExceptionsWork()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "TestComment",
             };
 
-            Assert.ThrowsException<SieveIncompatibleMethodException>(() => _processor.Apply(model, _posts));
+            Assert.Throws<SieveIncompatibleMethodException>(() => _processor.Apply(model, _posts));
         }
 
-        [TestMethod]
+        [Fact]
         public void OrNameFilteringWorks()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "(Title|LikeCount)==3",
             };
@@ -348,17 +373,17 @@ namespace SieveUnitTests
             var entry = result.FirstOrDefault();
             var resultCount = result.Count();
 
-            Assert.IsNotNull(entry);
-            Assert.AreEqual(1, resultCount);
-            Assert.AreEqual(3, entry.Id);
+            Assert.NotNull(entry);
+            Assert.Equal(1, resultCount);
+            Assert.Equal(3, entry.Id);
         }
 
-        [DataTestMethod]
-        [DataRow("CategoryId==1,(CategoryId|LikeCount)==50")]
-        [DataRow("(CategoryId|LikeCount)==50,CategoryId==1")]
+        [Theory]
+        [InlineData("CategoryId==1,(CategoryId|LikeCount)==50")]
+        [InlineData("(CategoryId|LikeCount)==50,CategoryId==1")]
         public void CombinedAndOrFilterIndependentOfOrder(string filter)
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = filter,
             };
@@ -367,14 +392,14 @@ namespace SieveUnitTests
             var entry = result.FirstOrDefault();
             var resultCount = result.Count();
 
-            Assert.IsNotNull(entry);
-            Assert.AreEqual(1, resultCount);
+            Assert.NotNull(entry);
+            Assert.Equal(1, resultCount);
         }
 
-        [TestMethod]
+        [Fact]
         public void CombinedAndOrWithSpaceFilteringWorks()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "Title==D, (Title|LikeCount)==3",
             };
@@ -383,97 +408,98 @@ namespace SieveUnitTests
             var entry = result.FirstOrDefault();
             var resultCount = result.Count();
 
-            Assert.IsNotNull(entry);
-            Assert.AreEqual(1, resultCount);
-            Assert.AreEqual(3, entry.Id);
+            Assert.NotNull(entry);
+            Assert.Equal(1, resultCount);
+            Assert.Equal(3, entry.Id);
         }
 
-        [TestMethod]
+        [Fact]
         public void OrValueFilteringWorks()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "Title==C|D",
             };
 
             var result = _processor.Apply(model, _posts);
-            Assert.AreEqual(2, result.Count());
-            Assert.IsTrue(result.Any(p => p.Id == 2));
-            Assert.IsTrue(result.Any(p => p.Id == 3));
+            Assert.Equal(2, result.Count());
+            Assert.True(result.Any(p => p.Id == 2));
+            Assert.True(result.Any(p => p.Id == 3));
         }
 
-        [TestMethod]
+        [Fact]
         public void OrValueFilteringWorks2()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "Text@=(|)",
             };
 
             var result = _processor.Apply(model, _comments);
-            Assert.AreEqual(1, result.Count());
-            Assert.AreEqual(2, result.FirstOrDefault().Id);
+            Assert.Equal(1, result.Count());
+            Assert.Equal(2, result.FirstOrDefault()?.Id);
         }
 
-        [TestMethod]
+        [Fact]
         public void NestedFilteringWorks()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "TopComment.Text!@=A",
             };
 
             var result = _processor.Apply(model, _posts);
-            Assert.AreEqual(3, result.Count());
+            Assert.Equal(3, result.Count());
             var posts = result.ToList();
-            Assert.IsTrue(posts[0].TopComment.Text.Contains("B"));
-            Assert.IsTrue(posts[1].TopComment.Text.Contains("C"));
-            Assert.IsTrue(posts[2].TopComment.Text.Contains("D"));
+            Assert.Contains("B", posts[0].TopComment.Text);
+            Assert.Contains("C", posts[1].TopComment.Text);
+            Assert.Contains("D", posts[2].TopComment.Text);
         }
 
-        [TestMethod]
+        [Fact]
         public void NestedSortingWorks()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Sorts = "TopComment.Id",
             };
 
             var result = _processor.Apply(model, _posts);
-            Assert.AreEqual(4, result.Count());
+            Assert.Equal(4, result.Count());
             var posts = result.ToList();
-            Assert.AreEqual(posts[0].Id, 0);
-            Assert.AreEqual(posts[1].Id, 3);
-            Assert.AreEqual(posts[2].Id, 2);
-            Assert.AreEqual(posts[3].Id, 1);
+            Assert.Equal(0, posts[0].Id);
+            Assert.Equal(3, posts[1].Id);
+            Assert.Equal(2, posts[2].Id);
+            Assert.Equal(1, posts[3].Id);
         }
 
-        [TestMethod]
+        [Fact]
         public void NestedFilteringWithIdenticTypesWorks()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "(topc|featc)@=*2",
             };
 
             var result = _processor.Apply(model, _posts);
-            Assert.AreEqual(4, result.Count());
+            Assert.Equal(4, result.Count());
 
-            model = new SieveModel()
+            model = new SieveModel
             {
                 Filters = "(topc|featc)@=*B",
             };
 
             result = _processor.Apply(model, _posts);
-            Assert.AreEqual(1, result.Count());
+            Assert.Equal(1, result.Count());
         }
 
-        [TestMethod]
+        [Fact]
         public void FilteringNullsWorks()
         {
             var posts = new List<Post>
             {
-                new Post() {
+                new Post
+                {
                     Id = 1,
                     Title = null,
                     LikeCount = 0,
@@ -484,21 +510,22 @@ namespace SieveUnitTests
                 },
             }.AsQueryable();
 
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "FeaturedComment.Text!@=Some value",
             };
 
             var result = _processor.Apply(model, posts);
-            Assert.AreEqual(0, result.Count());
+            Assert.Equal(0, result.Count());
         }
 
-        [TestMethod]
+        [Fact]
         public void SortingNullsWorks()
         {
             var posts = new List<Post>
             {
-                new Post() {
+                new Post
+                {
                     Id = 1,
                     Title = null,
                     LikeCount = 0,
@@ -507,7 +534,8 @@ namespace SieveUnitTests
                     TopComment =  new Comment { Id = 1 },
                     FeaturedComment = null
                 },
-                new Post() {
+                new Post
+                {
                     Id = 2,
                     Title = null,
                     LikeCount = 0,
@@ -518,24 +546,25 @@ namespace SieveUnitTests
                 },
             }.AsQueryable();
 
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Sorts = "TopComment.Id",
             };
 
             var result = _processor.Apply(model, posts);
-            Assert.AreEqual(2, result.Count());
+            Assert.Equal(2, result.Count());
             var sortedPosts = result.ToList();
-            Assert.AreEqual(sortedPosts[0].Id, 2);
-            Assert.AreEqual(sortedPosts[1].Id, 1);
+            Assert.Equal(2, sortedPosts[0].Id);
+            Assert.Equal(1, sortedPosts[1].Id);
         }
 
-        [TestMethod]
+        [Fact]
         public void FilteringOnNullWorks()
         {
             var posts = new List<Post>
             {
-                new Post() {
+                new Post
+                {
                     Id = 1,
                     Title = null,
                     LikeCount = 0,
@@ -544,7 +573,8 @@ namespace SieveUnitTests
                     TopComment = null,
                     FeaturedComment = null
                 },
-                new Post() {
+                new Post
+                {
                     Id = 2,
                     Title = null,
                     LikeCount = 0,
@@ -555,33 +585,33 @@ namespace SieveUnitTests
                 },
             }.AsQueryable();
 
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "FeaturedComment.Text==null",
             };
 
             var result = _processor.Apply(model, posts);
-            Assert.AreEqual(1, result.Count());
+            Assert.Equal(1, result.Count());
             var filteredPosts = result.ToList();
-            Assert.AreEqual(filteredPosts[0].Id, 2);
+            Assert.Equal(2, filteredPosts[0].Id);
         }
 
-        [TestMethod]
+        [Fact]
         public void BaseDefinedPropertyMappingSortingWorks_WithCustomName()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Sorts = "-CreateDate"
             };
 
             var result = _processor.Apply(model, _posts);
-            Assert.AreEqual(4, result.Count());
+            Assert.Equal(4, result.Count());
 
             var posts = result.ToList();
-            Assert.AreEqual(posts[0].Id, 3);
-            Assert.AreEqual(posts[1].Id, 2);
-            Assert.AreEqual(posts[2].Id, 1);
-            Assert.AreEqual(posts[3].Id, 0);
+            Assert.Equal(3,posts[0].Id);
+            Assert.Equal(2,posts[1].Id);
+            Assert.Equal(1,posts[2].Id);
+            Assert.Equal(0,posts[3].Id);
         }
     }
 }

SieveUnitTests/GeneralWithInterfaces.cs

@@ -1,33 +1,35 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Text;
-using Microsoft.VisualStudio.TestTools.UnitTesting;
 using Sieve.Exceptions;
 using Sieve.Models;
 using Sieve.Services;
 using SieveUnitTests.Abstractions.Entity;
 using SieveUnitTests.Entities;
 using SieveUnitTests.Services;
+using Xunit;
+using Xunit.Abstractions;
 
 namespace SieveUnitTests
 {
-    [TestClass]
     public class GeneralWithInterfaces
     {
+        private readonly ITestOutputHelper _testOutputHelper;
         private readonly SieveProcessor _processor;
         private readonly IQueryable<IPost> _posts;
         private readonly IQueryable<Comment> _comments;
 
-        public GeneralWithInterfaces()
+        public GeneralWithInterfaces(ITestOutputHelper testOutputHelper)
         {
+            _testOutputHelper = testOutputHelper;
             _processor = new ApplicationSieveProcessor(new SieveOptionsAccessor(),
                 new SieveCustomSortMethods(),
                 new SieveCustomFilterMethods());
 
             _posts = new List<IPost>
             {
-                new Post() {
+                new Post
+                {
                     Id = 0,
                     Title = "A",
                     LikeCount = 100,
@@ -36,7 +38,8 @@ namespace SieveUnitTests
                     TopComment = new Comment { Id = 0, Text = "A1" },
                     FeaturedComment = new Comment { Id = 4, Text = "A2" }
                 },
-                new Post() {
+                new Post
+                {
                     Id = 1,
                     Title = "B",
                     LikeCount = 50,
@@ -45,7 +48,8 @@ namespace SieveUnitTests
                     TopComment = new Comment { Id = 3, Text = "B1" },
                     FeaturedComment = new Comment { Id = 5, Text = "B2" }
                 },
-                new Post() {
+                new Post
+                {
                     Id = 2,
                     Title = "C",
                     LikeCount = 0,
@@ -53,7 +57,8 @@ namespace SieveUnitTests
                     TopComment = new Comment { Id = 2, Text = "C1" },
                     FeaturedComment = new Comment { Id = 6, Text = "C2" }
                 },
-                new Post() {
+                new Post
+                {
                     Id = 3,
                     Title = "D",
                     LikeCount = 3,
@@ -66,17 +71,20 @@ namespace SieveUnitTests
 
             _comments = new List<Comment>
             {
-                new Comment() {
+                new Comment
+                {
                     Id = 0,
                     DateCreated = DateTimeOffset.UtcNow.AddDays(-20),
                     Text = "This is an old comment."
                 },
-                new Comment() {
+                new Comment
+                {
                     Id = 1,
                     DateCreated = DateTimeOffset.UtcNow.AddDays(-1),
                     Text = "This is a fairly new comment."
                 },
-                new Comment() {
+                new Comment
+                {
                     Id = 2,
                     DateCreated = DateTimeOffset.UtcNow,
                     Text = "This is a brand new comment. (Text in braces)"
@@ -84,263 +92,263 @@ namespace SieveUnitTests
             }.AsQueryable();
         }
 
-        [TestMethod]
+        [Fact]
         public void ContainsCanBeCaseInsensitive()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "Title@=*a"
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.AreEqual(result.First().Id, 0);
-            Assert.IsTrue(result.Count() == 1);
+            Assert.Equal(0, result.First().Id);
+            Assert.True(result.Count() == 1);
         }
 
-        [TestMethod]
+        [Fact]
         public void NotEqualsCanBeCaseInsensitive()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "Title!=*a"
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.AreEqual(result.First().Id, 1);
-            Assert.IsTrue(result.Count() == 3);
+            Assert.Equal(1, result.First().Id);
+            Assert.True(result.Count() == 3);
         }
 
-        [TestMethod]
+        [Fact]
         public void ContainsIsCaseSensitive()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "Title@=a",
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.IsTrue(result.Count() == 0);
+            Assert.True(!result.Any());
         }
 
-        [TestMethod]
+        [Fact]
         public void NotContainsWorks()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "Title!@=D",
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.IsTrue(result.Count() == 3);
+            Assert.True(result.Count() == 3);
         }
 
-        [TestMethod]
+        [Fact]
         public void CanFilterBools()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "IsDraft==false"
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.IsTrue(result.Count() == 2);
+            Assert.True(result.Count() == 2);
         }
 
-        [TestMethod]
+        [Fact]
         public void CanSortBools()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Sorts = "-IsDraft"
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.AreEqual(result.First().Id, 0);
+            Assert.Equal(0, result.First().Id);
         }
 
-        [TestMethod]
+        [Fact]
         public void CanFilterNullableInts()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "CategoryId==1"
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.IsTrue(result.Count() == 2);
+            Assert.True(result.Count() == 2);
         }
 
-        [TestMethod]
+        [Fact]
         public void EqualsDoesntFailWithNonStringTypes()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "LikeCount==50",
             };
 
-            Console.WriteLine(model.GetFiltersParsed()[0].Values);
-            Console.WriteLine(model.GetFiltersParsed()[0].Operator);
-            Console.WriteLine(model.GetFiltersParsed()[0].OperatorParsed);
+            _testOutputHelper.WriteLine(model.GetFiltersParsed()[0].Values.ToString());
+            _testOutputHelper.WriteLine(model.GetFiltersParsed()[0].Operator);
+            _testOutputHelper.WriteLine(model.GetFiltersParsed()[0].OperatorParsed.ToString());
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.AreEqual(result.First().Id, 1);
-            Assert.IsTrue(result.Count() == 1);
+            Assert.Equal(1, result.First().Id);
+            Assert.True(result.Count() == 1);
         }
 
-        [TestMethod]
+        [Fact]
         public void CustomFiltersWork()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "Isnew",
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.IsFalse(result.Any(p => p.Id == 0));
-            Assert.IsTrue(result.Count() == 3);
+            Assert.False(result.Any(p => p.Id == 0));
+            Assert.True(result.Count() == 3);
         }
 
-        [TestMethod]
+        [Fact]
         public void CustomGenericFiltersWork()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "Latest",
             };
 
             var result = _processor.Apply(model, _comments);
 
-            Assert.IsFalse(result.Any(p => p.Id == 0));
-            Assert.IsTrue(result.Count() == 2);
+            Assert.False(result.Any(p => p.Id == 0));
+            Assert.True(result.Count() == 2);
         }
 
-        [TestMethod]
+        [Fact]
         public void CustomFiltersWithOperatorsWork()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "HasInTitle==A",
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.IsTrue(result.Any(p => p.Id == 0));
-            Assert.IsTrue(result.Count() == 1);
+            Assert.True(result.Any(p => p.Id == 0));
+            Assert.True(result.Count() == 1);
         }
 
-        [TestMethod]
+        [Fact]
         public void CustomFiltersMixedWithUsualWork1()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "Isnew,CategoryId==2",
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.IsTrue(result.Any(p => p.Id == 3));
-            Assert.IsTrue(result.Count() == 1);
+            Assert.True(result.Any(p => p.Id == 3));
+            Assert.True(result.Count() == 1);
         }
 
-        [TestMethod]
+        [Fact]
         public void CustomFiltersMixedWithUsualWork2()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "CategoryId==2,Isnew",
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.IsTrue(result.Any(p => p.Id == 3));
-            Assert.IsTrue(result.Count() == 1);
+            Assert.True(result.Any(p => p.Id == 3));
+            Assert.True(result.Count() == 1);
         }
 
-        [TestMethod]
+        [Fact]
         public void CustomFiltersOnDifferentSourcesCanShareName()
         {
-            var postModel = new SieveModel()
+            var postModel = new SieveModel
             {
                 Filters = "CategoryId==2,Isnew",
             };
 
             var postResult = _processor.Apply(postModel, _posts);
 
-            Assert.IsTrue(postResult.Any(p => p.Id == 3));
-            Assert.AreEqual(1, postResult.Count());
+            Assert.True(postResult.Any(p => p.Id == 3));
+            Assert.Equal(1, postResult.Count());
 
-            var commentModel = new SieveModel()
+            var commentModel = new SieveModel
             {
                 Filters = "Isnew",
             };
 
             var commentResult = _processor.Apply(commentModel, _comments);
 
-            Assert.IsTrue(commentResult.Any(c => c.Id == 2));
-            Assert.AreEqual(2, commentResult.Count());
+            Assert.True(commentResult.Any(c => c.Id == 2));
+            Assert.Equal(2, commentResult.Count());
         }
 
-        [TestMethod]
+        [Fact]
         public void CustomSortsWork()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Sorts = "Popularity",
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.IsFalse(result.First().Id == 0);
+            Assert.False(result.First().Id == 0);
         }
 
-        [TestMethod]
+        [Fact]
         public void CustomGenericSortsWork()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Sorts = "Oldest",
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.IsTrue(result.Last().Id == 0);
+            Assert.True(result.Last().Id == 0);
         }
 
-        [TestMethod]
+        [Fact]
         public void MethodNotFoundExceptionWork()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "does not exist",
             };
 
-            Assert.ThrowsException<SieveMethodNotFoundException>(() => _processor.Apply(model, _posts));
+            Assert.Throws<SieveMethodNotFoundException>(() => _processor.Apply(model, _posts));
         }
 
-        [TestMethod]
+        [Fact]
         public void IncompatibleMethodExceptionsWork()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "TestComment",
             };
 
-            Assert.ThrowsException<SieveIncompatibleMethodException>(() => _processor.Apply(model, _posts));
+            Assert.Throws<SieveIncompatibleMethodException>(() => _processor.Apply(model, _posts));
         }
 
-        [TestMethod]
+        [Fact]
         public void OrNameFilteringWorks()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "(Title|LikeCount)==3",
             };
@@ -349,17 +357,17 @@ namespace SieveUnitTests
             var entry = result.FirstOrDefault();
             var resultCount = result.Count();
 
-            Assert.IsNotNull(entry);
-            Assert.AreEqual(1, resultCount);
-            Assert.AreEqual(3, entry.Id);
+            Assert.NotNull(entry);
+            Assert.Equal(1, resultCount);
+            Assert.Equal(3, entry.Id);
         }
 
-        [DataTestMethod]
-        [DataRow("CategoryId==1,(CategoryId|LikeCount)==50")]
-        [DataRow("(CategoryId|LikeCount)==50,CategoryId==1")]
+        [Theory]
+        [InlineData("CategoryId==1,(CategoryId|LikeCount)==50")]
+        [InlineData("(CategoryId|LikeCount)==50,CategoryId==1")]
         public void CombinedAndOrFilterIndependentOfOrder(string filter)
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = filter,
             };
@@ -368,14 +376,14 @@ namespace SieveUnitTests
             var entry = result.FirstOrDefault();
             var resultCount = result.Count();
 
-            Assert.IsNotNull(entry);
-            Assert.AreEqual(1, resultCount);
+            Assert.NotNull(entry);
+            Assert.Equal(1, resultCount);
         }
 
-        [TestMethod]
+        [Fact]
         public void CombinedAndOrWithSpaceFilteringWorks()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "Title==D, (Title|LikeCount)==3",
             };
@@ -384,97 +392,98 @@ namespace SieveUnitTests
             var entry = result.FirstOrDefault();
             var resultCount = result.Count();
 
-            Assert.IsNotNull(entry);
-            Assert.AreEqual(1, resultCount);
-            Assert.AreEqual(3, entry.Id);
+            Assert.NotNull(entry);
+            Assert.Equal(1, resultCount);
+            Assert.Equal(3, entry.Id);
         }
 
-        [TestMethod]
+        [Fact]
         public void OrValueFilteringWorks()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "Title==C|D",
             };
 
             var result = _processor.Apply(model, _posts);
-            Assert.AreEqual(2, result.Count());
-            Assert.IsTrue(result.Any(p => p.Id == 2));
-            Assert.IsTrue(result.Any(p => p.Id == 3));
+            Assert.Equal(2, result.Count());
+            Assert.True(result.Any(p => p.Id == 2));
+            Assert.True(result.Any(p => p.Id == 3));
         }
 
-        [TestMethod]
+        [Fact]
         public void OrValueFilteringWorks2()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "Text@=(|)",
             };
 
             var result = _processor.Apply(model, _comments);
-            Assert.AreEqual(1, result.Count());
-            Assert.AreEqual(2, result.FirstOrDefault().Id);
+            Assert.Equal(1, result.Count());
+            Assert.Equal(2, result.FirstOrDefault()?.Id);
         }
 
-        [TestMethod]
+        [Fact]
         public void NestedFilteringWorks()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "TopComment.Text!@=A",
             };
 
             var result = _processor.Apply(model, _posts);
-            Assert.AreEqual(3, result.Count());
+            Assert.Equal(3, result.Count());
             var posts = result.ToList();
-            Assert.IsTrue(posts[0].TopComment.Text.Contains("B"));
-            Assert.IsTrue(posts[1].TopComment.Text.Contains("C"));
-            Assert.IsTrue(posts[2].TopComment.Text.Contains("D"));
+            Assert.Contains("B", posts[0].TopComment.Text);
+            Assert.Contains("C", posts[1].TopComment.Text);
+            Assert.Contains("D", posts[2].TopComment.Text);
         }
 
-        [TestMethod]
+        [Fact]
         public void NestedSortingWorks()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Sorts = "TopComment.Id",
             };
 
             var result = _processor.Apply(model, _posts);
-            Assert.AreEqual(4, result.Count());
+            Assert.Equal(4, result.Count());
             var posts = result.ToList();
-            Assert.AreEqual(posts[0].Id, 0);
-            Assert.AreEqual(posts[1].Id, 3);
-            Assert.AreEqual(posts[2].Id, 2);
-            Assert.AreEqual(posts[3].Id, 1);
+            Assert.Equal(0, posts[0].Id);
+            Assert.Equal(3, posts[1].Id);
+            Assert.Equal(2, posts[2].Id);
+            Assert.Equal(1, posts[3].Id);
         }
 
-        [TestMethod]
+        [Fact]
         public void NestedFilteringWithIdenticTypesWorks()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "(topc|featc)@=*2",
             };
 
             var result = _processor.Apply(model, _posts);
-            Assert.AreEqual(4, result.Count());
+            Assert.Equal(4, result.Count());
 
-            model = new SieveModel()
+            model = new SieveModel
             {
                 Filters = "(topc|featc)@=*B",
             };
 
             result = _processor.Apply(model, _posts);
-            Assert.AreEqual(1, result.Count());
+            Assert.Equal(1, result.Count());
         }
 
-        [TestMethod]
+        [Fact]
         public void FilteringNullsWorks()
         {
             var posts = new List<Post>
             {
-                new Post() {
+                new Post
+                {
                     Id = 1,
                     Title = null,
                     LikeCount = 0,
@@ -485,21 +494,22 @@ namespace SieveUnitTests
                 },
             }.AsQueryable();
 
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "FeaturedComment.Text!@=Some value",
             };
 
             var result = _processor.Apply(model, posts);
-            Assert.AreEqual(0, result.Count());
+            Assert.Equal(0, result.Count());
         }
 
-        [TestMethod]
+        [Fact]
         public void SortingNullsWorks()
         {
             var posts = new List<Post>
             {
-                new Post() {
+                new Post
+                {
                     Id = 1,
                     Title = null,
                     LikeCount = 0,
@@ -508,7 +518,8 @@ namespace SieveUnitTests
                     TopComment =  new Comment { Id = 1 },
                     FeaturedComment = null
                 },
-                new Post() {
+                new Post
+                {
                     Id = 2,
                     Title = null,
                     LikeCount = 0,
@@ -519,24 +530,25 @@ namespace SieveUnitTests
                 },
             }.AsQueryable();
 
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Sorts = "TopComment.Id",
             };
 
             var result = _processor.Apply(model, posts);
-            Assert.AreEqual(2, result.Count());
+            Assert.Equal(2, result.Count());
             var sortedPosts = result.ToList();
-            Assert.AreEqual(sortedPosts[0].Id, 2);
-            Assert.AreEqual(sortedPosts[1].Id, 1);
+            Assert.Equal(2, sortedPosts[0].Id);
+            Assert.Equal(1, sortedPosts[1].Id);
         }
 
-        [TestMethod]
+        [Fact]
         public void FilteringOnNullWorks()
         {
             var posts = new List<Post>
             {
-                new Post() {
+                new Post
+                {
                     Id = 1,
                     Title = null,
                     LikeCount = 0,
@@ -545,7 +557,8 @@ namespace SieveUnitTests
                     TopComment = null,
                     FeaturedComment = null
                 },
-                new Post() {
+                new Post
+                {
                     Id = 2,
                     Title = null,
                     LikeCount = 0,
@@ -556,33 +569,33 @@ namespace SieveUnitTests
                 },
             }.AsQueryable();
 
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "FeaturedComment.Text==null",
             };
 
             var result = _processor.Apply(model, posts);
-            Assert.AreEqual(1, result.Count());
+            Assert.Equal(1, result.Count());
             var filteredPosts = result.ToList();
-            Assert.AreEqual(filteredPosts[0].Id, 2);
+            Assert.Equal(2, filteredPosts[0].Id);
         }
 
-        [TestMethod]
+        [Fact]
         public void BaseDefinedPropertyMappingSortingWorks_WithCustomName()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Sorts = "-CreateDate"
             };
 
             var result = _processor.Apply(model, _posts);
-            Assert.AreEqual(4, result.Count());
+            Assert.Equal(4, result.Count());
 
             var posts = result.ToList();
-            Assert.AreEqual(posts[0].Id, 3);
-            Assert.AreEqual(posts[1].Id, 2);
-            Assert.AreEqual(posts[2].Id, 1);
-            Assert.AreEqual(posts[3].Id, 0);
+            Assert.Equal(3,posts[0].Id);
+            Assert.Equal(2,posts[1].Id);
+            Assert.Equal(1,posts[2].Id);
+            Assert.Equal(0,posts[3].Id);
         }
     }
 }

SieveUnitTests/Mapper.cs

@@ -1,14 +1,13 @@
 using System.Collections.Generic;
 using System.Linq;
-using Microsoft.VisualStudio.TestTools.UnitTesting;
 using Sieve.Exceptions;
 using Sieve.Models;
 using SieveUnitTests.Entities;
 using SieveUnitTests.Services;
+using Xunit;
 
 namespace SieveUnitTests
 {
-    [TestClass]
     public class Mapper
     {
         private readonly ApplicationSieveProcessor _processor;
@@ -22,19 +21,22 @@ namespace SieveUnitTests
 
             _posts = new List<Post>
             {
-                new Post() {
+                new Post
+                {
                     Id = 1,
                     ThisHasNoAttributeButIsAccessible = "A",
                     ThisHasNoAttribute = "A",
                     OnlySortableViaFluentApi = 100
                 },
-                new Post() {
+                new Post
+                {
                     Id = 2,
                     ThisHasNoAttributeButIsAccessible = "B",
                     ThisHasNoAttribute = "B",
                     OnlySortableViaFluentApi = 50
                 },
-                new Post() {
+                new Post
+                {
                     Id = 3,
                     ThisHasNoAttributeButIsAccessible = "C",
                     ThisHasNoAttribute = "C",
@@ -43,25 +45,25 @@ namespace SieveUnitTests
             }.AsQueryable();
         }
 
-        [TestMethod]
+        [Fact]
         public void MapperWorks()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "shortname@=A",
             };
 
             var result = _processor.Apply(model, _posts);
 
-            Assert.AreEqual(result.First().ThisHasNoAttributeButIsAccessible, "A");
+            Assert.Equal("A", result.First().ThisHasNoAttributeButIsAccessible);
 
-            Assert.IsTrue(result.Count() == 1);
+            Assert.True(result.Count() == 1);
         }
 
-        [TestMethod]
+        [Fact]
         public void MapperSortOnlyWorks()
         {
-            var model = new SieveModel()
+            var model = new SieveModel
             {
                 Filters = "OnlySortableViaFluentApi@=50",
                 Sorts = "OnlySortableViaFluentApi"
@@ -69,17 +71,11 @@ namespace SieveUnitTests
 
             var result = _processor.Apply(model, _posts, applyFiltering: false, applyPagination: false);
 
-            Assert.ThrowsException<SieveMethodNotFoundException>(() => _processor.Apply(model, _posts));
+            Assert.Throws<SieveMethodNotFoundException>(() => _processor.Apply(model, _posts));
 
-            Assert.AreEqual(result.First().Id, 3);
+            Assert.Equal(3, result.First().Id);
 
-            Assert.IsTrue(result.Count() == 3);
+            Assert.True(result.Count() == 3);
         }
     }
 }
-
-//
-//Sorts = "LikeCount",
-//Page = 1,
-//PageSize = 10
-//

SieveUnitTests/SieveUnitTests.csproj

@@ -1,15 +1,22 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp2.0</TargetFramework>
-
+    <TargetFramework>netcoreapp3.1</TargetFramework>
     <IsPackable>false</IsPackable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.5.0" />
-    <PackageReference Include="MSTest.TestAdapter" Version="1.2.0" />
-    <PackageReference Include="MSTest.TestFramework" Version="1.2.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.7.1" />
+    <PackageReference Include="Microsoft.Extensions.Options" Version="2.0.0" />
+    <PackageReference Include="xunit" Version="2.4.1" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="coverlet.collector" Version="1.3.0">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
   </ItemGroup>
 
   <ItemGroup>

SieveUnitTests/StringFilterNullTests.cs

@@ -0,0 +1,148 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Sieve.Models;
+using Sieve.Services;
+using SieveUnitTests.Entities;
+using SieveUnitTests.Services;
+using Xunit;
+
+namespace SieveUnitTests
+{
+    public class StringFilterNullTests
+    {
+        private readonly IQueryable<Comment> _comments;
+        private readonly SieveProcessor _processor;
+
+        public StringFilterNullTests()
+        {
+            _processor = new SieveProcessor(new SieveOptionsAccessor());
+
+            _comments = new List<Comment>
+            {
+                new Comment
+                {
+                    Id = 0,
+                    DateCreated = DateTimeOffset.UtcNow,
+                    Text = "This text contains null somewhere in the middle of a string",
+                    Author = "Dog",
+                },
+                new Comment
+                {
+                    Id = 1,
+                    DateCreated = DateTimeOffset.UtcNow, 
+                    Text = "null is here in the text",
+                    Author = "Cat",
+                },
+                new Comment
+                {
+                    Id = 2, 
+                    DateCreated = DateTimeOffset.UtcNow, 
+                    Text = "Regular comment without n*ll.",
+                    Author = "Mouse",
+                },
+                new Comment
+                {
+                    Id = 100, 
+                    DateCreated = DateTimeOffset.UtcNow, 
+                    Text = null,
+                    Author = "null",
+                },
+            }.AsQueryable();
+        }
+
+        [Fact]
+        public void Filter_Equals_Null()
+        {
+            var model = new SieveModel {Filters = "Text==null"};
+
+            var result = _processor.Apply(model, _comments);
+
+            Assert.Equal(100, result.Single().Id);
+        }
+
+        [Fact]
+        public void Filter_NotEquals_Null()
+        {
+            var model = new SieveModel {Filters = "Text!=null"};
+
+            var result = _processor.Apply(model, _comments);
+
+            Assert.Equal(new[] {0, 1, 2}, result.Select(p => p.Id));
+        }
+
+        [Theory]
+        [InlineData("Text@=null")]
+        [InlineData("Text@=*null")]
+        [InlineData("Text@=*NULL")]
+        [InlineData("Text@=*NulL")]
+        [InlineData("Text@=*null|text")]
+        public void Filter_Contains_NullString(string filter)
+        {
+            var model = new SieveModel {Filters = filter};
+
+            var result = _processor.Apply(model, _comments);
+
+            Assert.Equal(new[] {0, 1}, result.Select(p => p.Id));
+        }
+        
+        [Theory]
+        [InlineData("Text|Author==null", 100)]
+        [InlineData("Text|Author@=null", 0, 1, 100)]
+        [InlineData("Text|Author@=*null", 0, 1, 100)]
+        [InlineData("Text|Author_=null", 1, 100)]
+        [InlineData("Text|Author_=*null", 1, 100)]
+        public void MultiFilter_Contains_NullString(string filter, params int[] expectedIds)
+        {
+            var model = new SieveModel {Filters = filter};
+
+            var result = _processor.Apply(model, _comments);
+
+            Assert.Equal(expectedIds, result.Select(p => p.Id));
+        }
+
+        [Theory]
+        [InlineData("Text_=null")]
+        [InlineData("Text_=*null")]
+        [InlineData("Text_=*NULL")]
+        [InlineData("Text_=*NulL")]
+        [InlineData("Text_=*null|text")]
+        public void Filter_StartsWith_NullString(string filter)
+        {
+            var model = new SieveModel {Filters = filter};
+
+            var result = _processor.Apply(model, _comments);
+
+            Assert.Equal(new[] {1}, result.Select(p => p.Id));
+        }
+
+        [Theory]
+        [InlineData("Text!@=null")]
+        [InlineData("Text!@=*null")]
+        [InlineData("Text!@=*NULL")]
+        [InlineData("Text!@=*NulL")]
+        [InlineData("Text!@=*null|text")]
+        public void Filter_DoesNotContain_NullString(string filter)
+        {
+            var model = new SieveModel {Filters = filter};
+
+            var result = _processor.Apply(model, _comments);
+
+            Assert.Equal(new[] {2}, result.Select(p => p.Id));
+        }
+
+        [Theory]
+        [InlineData("Text!_=null")]
+        [InlineData("Text!_=*null")]
+        [InlineData("Text!_=*NULL")]
+        [InlineData("Text!_=*NulL")]
+        public void Filter_DoesNotStartsWith_NullString(string filter)
+        {
+            var model = new SieveModel {Filters = filter};
+
+            var result = _processor.Apply(model, _comments);
+
+            Assert.Equal(new[] {0, 2}, result.Select(p => p.Id));
+        }
+    }
+}