Plugging in Assertion extensibility

TestFx.sln

@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio 15
-VisualStudioVersion = 15.0.26217.2
+VisualStudioVersion = 15.0.26228.9
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "src", "src", "{FF8B1B72-55A1-4FFE-809E-7B79323ED8D0}"
 EndProject
@@ -100,6 +100,9 @@ EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "PlatformServices.Desktop.Component.Tests", "test\ComponentTests\PlatformServices.Desktop.Component.Tests\PlatformServices.Desktop.Component.Tests.csproj", "{4EA6EED3-0579-4C7C-94EA-52B2AD2A9D39}"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Smoke.E2E.Tests", "test\E2ETests\Smoke.E2E.Tests\Smoke.E2E.Tests.csproj", "{A94E3FCA-2FB3-4C79-9F39-5B652B6992F0}"
+	ProjectSection(ProjectDependencies) = postProject
+		{4004757A-0080-4410-B90A-6169B20F151B} = {4004757A-0080-4410-B90A-6169B20F151B}
+	EndProjectSection
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Automation.CLI", "test\E2ETests\Automation.CLI\Automation.CLI.csproj", "{9C1219E0-E775-47F9-9236-63F03F774801}"
 	ProjectSection(ProjectDependencies) = postProject
@@ -151,6 +154,12 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "scripts", "scripts", "{BCF5
 		scripts\UpdateTemplates.ps1 = scripts\UpdateTemplates.ps1
 	EndProjectSection
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "samples", "samples", "{92F8E9A2-903E-4025-99BC-7DC478D5466D}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "FxExtensibility", "samples\FxExtensibility\FxExtensibility.csproj", "{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "FxExtensibilityTestProject", "test\E2ETests\TestAssets\FxExtensibilityTestProject\FxExtensibilityTestProject.csproj", "{4004757A-0080-4410-B90A-6169B20F151B}"
+EndProject
 Global
 	GlobalSection(SharedMSBuildProjectFiles) = preSolution
 		src\TestFramework\Extension.Shared\Extension.Shared.projitems*{272ca5e1-8e81-4825-9e47-86cce02f700d}*SharedItemsImports = 13
@@ -754,6 +763,54 @@ Global
 		{0A4A76DD-FEE1-4D04-926B-38E1A24A7ED2}.Release|x64.Build.0 = Release|Any CPU
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 		{0A4A76DD-FEE1-4D04-926B-38E1A24A7ED2}.Release|x86.Build.0 = Release|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Code Analysis Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Code Analysis Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Code Analysis Debug|ARM.ActiveCfg = Debug|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Code Analysis Debug|ARM.Build.0 = Debug|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Code Analysis Debug|x64.ActiveCfg = Debug|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Code Analysis Debug|x64.Build.0 = Debug|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Code Analysis Debug|x86.ActiveCfg = Debug|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Code Analysis Debug|x86.Build.0 = Debug|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Debug|ARM.ActiveCfg = Debug|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Debug|ARM.Build.0 = Debug|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Debug|x64.Build.0 = Debug|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Debug|x86.Build.0 = Debug|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Release|Any CPU.Build.0 = Release|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Release|ARM.ActiveCfg = Release|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Release|ARM.Build.0 = Release|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Release|x64.ActiveCfg = Release|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Release|x64.Build.0 = Release|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Release|x86.ActiveCfg = Release|Any CPU
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}.Release|x86.Build.0 = Release|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Code Analysis Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Code Analysis Debug|Any CPU.Build.0 = Debug|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Code Analysis Debug|ARM.ActiveCfg = Debug|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Code Analysis Debug|ARM.Build.0 = Debug|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Code Analysis Debug|x64.ActiveCfg = Debug|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Code Analysis Debug|x64.Build.0 = Debug|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Code Analysis Debug|x86.ActiveCfg = Debug|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Code Analysis Debug|x86.Build.0 = Debug|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Debug|ARM.ActiveCfg = Debug|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Debug|ARM.Build.0 = Debug|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Debug|x64.Build.0 = Debug|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Debug|x86.Build.0 = Debug|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Release|Any CPU.Build.0 = Release|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Release|ARM.ActiveCfg = Release|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Release|ARM.Build.0 = Release|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Release|x64.ActiveCfg = Release|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Release|x64.Build.0 = Release|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Release|x86.ActiveCfg = Release|Any CPU
+		{4004757A-0080-4410-B90A-6169B20F151B}.Release|x86.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -804,5 +861,7 @@ Global
 		{FE0DF239-0D81-46CA-9277-3342009E83F9} = {929A3EDE-893B-4801-82BA-01FD947291CB}
 		{F60B647A-E14C-48AF-9BD6-89F44EB60115} = {929A3EDE-893B-4801-82BA-01FD947291CB}
 		{BCF525B1-E67F-486D-B091-06A8BB8A2793} = {929A3EDE-893B-4801-82BA-01FD947291CB}
+		{A82770C0-1FF5-43C7-8790-471D5E4F8D6E} = {92F8E9A2-903E-4025-99BC-7DC478D5466D}
+		{4004757A-0080-4410-B90A-6169B20F151B} = {D53BD452-F69F-4FB3-8B98-386EDA28A4C8}
 	EndGlobalSection
 EndGlobal

samples/FxExtensibility/AssertEx.cs

@@ -0,0 +1,49 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+namespace MSTest.Extensibility.Samples
+{
+    using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+    public static class AssertEx
+    {
+        private static AssertIs assertis;
+
+        /// <summary>
+        /// A simple assert extension to validate if an object is of a given type.
+        /// </summary>
+        /// <typeparam name="T">The type to check.</typeparam>
+        /// <param name="assert">Assert class.</param>
+        /// <param name="obj">The object.</param>
+        /// <returns>True if object is of the given type.</returns>
+        /// <exception cref="AssertFailedException">If object is not of the given type.</exception>
+        public static bool IsOfType<T>(this Assert assert, object obj)
+        {
+            if (obj is T)
+            {
+                return true;
+            }
+
+            throw new AssertFailedException(
+                string.Format(
+                "Expected object of type {0} but found object of type {1}",
+                typeof(T),
+                obj ?? obj.GetType()));
+        }
+
+        /// <summary>
+        /// A chain/grouping of assert statements.
+        /// </summary>
+        /// <param name="assert">The Assert class.</param>
+        /// <returns>The class that contains the assert methods for this grouping.</returns>
+        public static AssertIs Is(this Assert assert)
+        {
+            if (assertis == null)
+            {
+                assertis = new AssertIs();
+            }
+
+            return assertis;
+        }
+    }
+}

samples/FxExtensibility/AssertIs.cs

@@ -0,0 +1,46 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+namespace MSTest.Extensibility.Samples
+{
+    using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+    /// <summary>
+    /// A grouping of Assert statements with similar functionality.
+    /// </summary>
+    public class AssertIs
+    {
+        /// <summary>
+        /// Determines if the 'divisor' is actually a divisor of 'number'.
+        /// </summary>
+        /// <param name="number">A number.</param>
+        /// <param name="divisor">Its proclaimed divisor.</param>
+        /// <returns>True if it is a divisor</returns>
+        /// <exception cref="AssertFailedException">If it is not a divisor.</exception>
+        public bool Divisor(int number, int divisor)
+        {
+            if (number % divisor == 0)
+            {
+                return true;
+            }
+
+            throw new AssertFailedException(string.Format("{0} is not a divisor of {1}", divisor, number));
+        }
+
+        /// <summary>
+        /// Determines if a number is positive.
+        /// </summary>
+        /// <param name="number">The number.</param>
+        /// <returns>True if it is positive.</returns>
+        /// <exception cref="AssertFailedException">If the number is not positive.</exception>
+        public bool Positive(int number)
+        {
+            if (number > 0)
+            {
+                return true;
+            }
+
+            throw new AssertFailedException(string.Format("{0} is not positive", number));
+        }
+    }
+}

samples/FxExtensibility/FxExtensibility.csproj

@@ -0,0 +1,48 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <TestFxRoot Condition="$(TestFxRoot) == ''">..\..\</TestFxRoot>
+  </PropertyGroup>
+  <Import Project="$(TestFxRoot)scripts\build\TestFx.Settings.targets" />
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProjectGuid>{A82770C0-1FF5-43C7-8790-471D5E4F8D6E}</ProjectGuid>
+    <OutputType>Library</OutputType>
+    <AppDesignerFolder>Properties</AppDesignerFolder>
+    <RootNamespace>MSTest.Extensibility.Samples</RootNamespace>
+    <AssemblyName>MSTest.Extensibility.Samples</AssemblyName>
+    <TargetFrameworkVersion>v4.5.2</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="System" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="AssertEx.cs" />
+    <Compile Include="AssertIs.cs" />
+    <Compile Include="Properties\AssemblyInfo.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\TestFramework\MSTest.Core\MSTest.Core.csproj">
+      <Project>{7252d9e3-267d-442c-96bc-c73aef3241d6}</Project>
+      <Name>MSTest.Core</Name>
+    </ProjectReference>
+  </ItemGroup>
+  <Import Project="$(TestFxRoot)scripts\build\TestFx.targets" />
+</Project>

samples/FxExtensibility/Properties/AssemblyInfo.cs

@@ -0,0 +1,36 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System.Reflection;
+using System.Runtime.InteropServices;
+
+// General Information about an assembly is controlled through the following
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+[assembly: AssemblyTitle("MSTest.Extensibility.Samples")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("FxExtensibility")]
+[assembly: AssemblyCopyright("Copyright ©  2017")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// Setting ComVisible to false makes the types in this assembly not visible
+// to COM components.  If you need to access a type in this assembly from
+// COM, set the ComVisible attribute to true on that type.
+[assembly: ComVisible(false)]
+
+// The following GUID is for the ID of the typelib if this project is exposed to COM
+[assembly: Guid("a82770c0-1ff5-43c7-8790-471d5e4f8d6e")]
+
+// Version information for an assembly consists of the following four values:
+//
+//      Major Version
+//      Minor Version
+//      Build Number
+//      Revision
+//
+// You can specify all the values or you can default the Build and Revision Numbers
+// by using the '*' as shown below:
+// [assembly: AssemblyVersion("1.0.*")]

src/TestFramework/MSTest.Core/Assertions/Assert.cs

@@ -4,20 +4,46 @@
 namespace Microsoft.VisualStudio.TestTools.UnitTesting
 {
     using System;
-    using System.Collections.Generic;
     using System.Diagnostics.CodeAnalysis;
     using System.Globalization;
     using System.Reflection;
-    using System.Text;
     using System.Threading.Tasks;
 
     /// <summary>
     /// A collection of helper classes to test various conditions within
     /// unit tests. If the condition being tested is not met, an exception
     /// is thrown.
     /// </summary>
-    public static partial class Assert
+    public class Assert
     {
+        private static Assert that;
+
+        #region Singleton constructor
+
+        /// <summary>
+        /// Gets the singleton instance of the Assert functionality.
+        /// </summary>
+        /// <remarks>
+        /// Users can use this to plug-in custom assertions through C# extension methods.
+        /// For instance, the signature of a custom assertion provider could be "public static void IsOfType&lt;T&gt;(this Assert assert, object obj)"
+        /// Users could then use a syntax similar to the default assertions which in this case is "Assert.That.IsOfType&lt;Dog&gt;(animal);"
+        /// More documentation is at "https://github.com/Microsoft/testfx-docs".
+        /// </remarks>
+        public static Assert That
+        {
+            get
+            {
+               if (that == null)
+               {
+                   that = new Assert();
+               }
+
+                return that;
+            }
+        }
+
+        #endregion
+
         #region Boolean
 
         /// <summary>

src/TestFramework/MSTest.Core/Assertions/CollectionAssert.cs

@@ -15,8 +15,36 @@ namespace Microsoft.VisualStudio.TestTools.UnitTesting
     /// with collections within unit tests. If the condition being tested is not
     /// met, an exception is thrown.
     /// </summary>
-    public static class CollectionAssert
+    public class CollectionAssert
     {
+        private static CollectionAssert that;
+
+        #region Singleton constructor
+
+        /// <summary>
+        /// Gets the singleton instance of the CollectionAssert functionality.
+        /// </summary>
+        /// <remarks>
+        /// Users can use this to plug-in custom assertions through C# extension methods.
+        /// For instance, the signature of a custom assertion provider could be "public static void AreEqualUnordered(this CollectionAssert cusomtAssert, ICollection expected, ICollection actual)"
+        /// Users could then use a syntax similar to the default assertions which in this case is "CollectionAssert.That.AreEqualUnordered(list1, list2);"
+        /// More documentation is at "https://github.com/Microsoft/testfx-docs".
+        /// </remarks>
+        public static CollectionAssert That
+        {
+            get
+            {
+                if (that == null)
+                {
+                    that = new CollectionAssert();
+                }
+
+                return that;
+            }
+        }
+
+        #endregion
+
         #region Membership
 
         /// <summary>