Add Assert.Scope() for soft assertions

src/TestFramework/TestFramework/Assertions/Assert.Scope.cs

@@ -0,0 +1,29 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+namespace Microsoft.VisualStudio.TestTools.UnitTesting;
+
+/// <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 sealed partial class Assert
+{
+    /// <summary>
+    /// Creates a new assertion scope that collects assertion failures instead of throwing them immediately.
+    /// When the returned scope is disposed, all collected failures are thrown as a single <see cref="AssertFailedException"/>.
+    /// </summary>
+    /// <returns>An <see cref="IDisposable"/> representing the assertion scope.</returns>
+    /// <example>
+    /// <code>
+    /// using (Assert.Scope())
+    /// {
+    ///     Assert.AreEqual(1, 2);  // collected, not thrown
+    ///     Assert.IsTrue(false);   // collected, not thrown
+    /// }
+    /// // AssertFailedException is thrown here with all collected failures.
+    /// </code>
+    /// </example>
+    public static IDisposable Scope() => new AssertScope();
+}

src/TestFramework/TestFramework/Assertions/Assert.cs

@@ -37,8 +37,19 @@ private Assert()
     [DoesNotReturn]
     [StackTraceHidden]
     internal static void ThrowAssertFailed(string assertionName, string? message)
-        => throw new AssertFailedException(
-            string.Format(CultureInfo.CurrentCulture, FrameworkMessages.AssertionFailed, assertionName, message));
+    {
+        var assertionFailedException = new AssertFailedException(string.Format(CultureInfo.CurrentCulture, FrameworkMessages.AssertionFailed, assertionName, message));
+        AssertScope? scope = AssertScope.Current;
+        if (scope is not null)
+        {
+            scope.AddError(assertionFailedException);
+#pragma warning disable CS8763 // A method marked [DoesNotReturn] should not return.
+            return;
+#pragma warning restore CS8763 // A method marked [DoesNotReturn] should not return.
+        }
+
+        throw assertionFailedException;
+    }
 
     /// <summary>
     /// Builds the formatted message using the given user format message and parameters.

src/TestFramework/TestFramework/Assertions/AssertScope.cs

@@ -0,0 +1,53 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+namespace Microsoft.VisualStudio.TestTools.UnitTesting;
+
+/// <summary>
+/// Represents a scope in which assertion failures are collected instead of thrown immediately.
+/// When the scope is disposed, all collected failures are thrown as a single <see cref="AssertFailedException"/>.
+/// </summary>
+internal sealed class AssertScope : IDisposable
+{
+    private static readonly AsyncLocal<AssertScope?> CurrentScope = new();
+
+    private readonly List<AssertFailedException> _errors = [];
+    private readonly AssertScope? _previousScope;
+    private bool _disposed;
+
+    internal AssertScope()
+    {
+        _previousScope = CurrentScope.Value;
+        CurrentScope.Value = this;
+    }
+
+    /// <summary>
+    /// Gets the current active <see cref="AssertScope"/>, or <see langword="null"/> if no scope is active.
+    /// </summary>
+    internal static AssertScope? Current => CurrentScope.Value;
+
+    /// <summary>
+    /// Adds an assertion failure message to the current scope.
+    /// </summary>
+    /// <param name="error">The assertion failure message.</param>
+    internal void AddError(AssertFailedException error) => _errors.Add(error);
+
+    /// <inheritdoc/>
+    public void Dispose()
+    {
+        if (_disposed)
+        {
+            return;
+        }
+
+        _disposed = true;
+        CurrentScope.Value = _previousScope;
+
+        if (_errors.Count > 0)
+        {
+            throw new AssertFailedException(
+                string.Format(CultureInfo.CurrentCulture, FrameworkMessages.AssertScopeFailure, _errors.Count),
+                new AggregateException(_errors));
+        }
+    }
+}

src/TestFramework/TestFramework/Resources/FrameworkMessages.resx

@@ -393,4 +393,8 @@ Actual: {2}</value>
   <data name="IsInRangeMaxValueMustBeGreaterThanOrEqualMinValue" xml:space="preserve">
     <value>The maximum value must be greater than or equal to the minimum value.</value>
   </data>
+  <data name="AssertScopeFailure" xml:space="preserve">
+    <value>{0} assertion(s) failed within the assert scope:</value>
+    <comment>{0} is the number of assertion failures collected in the scope.</comment>
+  </data>
 </root>

src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.cs.xlf

@@ -458,6 +458,11 @@ Skutečnost: {2}</target>
         <target state="translated">CollectionAssert.ReferenceEquals se nemá používat pro kontrolní výrazy. Místo toho použijte metody CollectionAssert nebo Assert.AreSame &amp; overloads.</target>
         <note></note>
       </trans-unit>
+      <trans-unit id="AssertScopeFailure">
+        <source>{0} assertion(s) failed within the assert scope:</source>
+        <target state="new">{0} assertion(s) failed within the assert scope:</target>
+        <note>{0} is the number of assertion failures collected in the scope.</note>
+      </trans-unit>
     </body>
   </file>
 </xliff>

src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.de.xlf

@@ -458,6 +458,11 @@ Tatsächlich: {2}</target>
         <target state="translated">CollectionAssert.ReferenceEquals darf nicht für Assertions verwendet werden. Verwenden Sie stattdessen CollectionAssert-Methoden oder Assert.AreSame und Überladungen.</target>
         <note></note>
       </trans-unit>
+      <trans-unit id="AssertScopeFailure">
+        <source>{0} assertion(s) failed within the assert scope:</source>
+        <target state="new">{0} assertion(s) failed within the assert scope:</target>
+        <note>{0} is the number of assertion failures collected in the scope.</note>
+      </trans-unit>
     </body>
   </file>
 </xliff>

src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.es.xlf

@@ -458,6 +458,11 @@ Real: {2}</target>
         <target state="translated">CollectionAssert.ReferenceEquals no se debe usar para las aserciones. Use los métodos CollectionAssert o las sobrecargas Assert.AreSame &amp; en su lugar.</target>
         <note></note>
       </trans-unit>
+      <trans-unit id="AssertScopeFailure">
+        <source>{0} assertion(s) failed within the assert scope:</source>
+        <target state="new">{0} assertion(s) failed within the assert scope:</target>
+        <note>{0} is the number of assertion failures collected in the scope.</note>
+      </trans-unit>
     </body>
   </file>
 </xliff>

src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.fr.xlf

@@ -458,6 +458,11 @@ Réel : {2}</target>
         <target state="translated">CollectionAssert.ReferenceEquals ne doit pas être utilisé pour les assertions. Utilisez plutôt les méthodes CollectionAssert ou Assert.AreSame &amp; overloads.</target>
         <note></note>
       </trans-unit>
+      <trans-unit id="AssertScopeFailure">
+        <source>{0} assertion(s) failed within the assert scope:</source>
+        <target state="new">{0} assertion(s) failed within the assert scope:</target>
+        <note>{0} is the number of assertion failures collected in the scope.</note>
+      </trans-unit>
     </body>
   </file>
 </xliff>

src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.it.xlf

@@ -458,6 +458,11 @@ Effettivo: {2}</target>
         <target state="translated">Non è possibile usare CollectionAssert.ReferenceEquals per le asserzioni. In alternativa, usare i metodi CollectionAssert o Assert.AreSame e gli overload.</target>
         <note></note>
       </trans-unit>
+      <trans-unit id="AssertScopeFailure">
+        <source>{0} assertion(s) failed within the assert scope:</source>
+        <target state="new">{0} assertion(s) failed within the assert scope:</target>
+        <note>{0} is the number of assertion failures collected in the scope.</note>
+      </trans-unit>
     </body>
   </file>
 </xliff>

src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.ja.xlf

@@ -458,6 +458,11 @@ Actual: {2}</source>
         <target state="translated">アサーションには CollectionAssert.ReferenceEquals を使用しないでください。代わりに CollectionAssert メソッドまたは Assert.AreSame およびオーバーロードを使用してください。</target>
         <note></note>
       </trans-unit>
+      <trans-unit id="AssertScopeFailure">
+        <source>{0} assertion(s) failed within the assert scope:</source>
+        <target state="new">{0} assertion(s) failed within the assert scope:</target>
+        <note>{0} is the number of assertion failures collected in the scope.</note>
+      </trans-unit>
     </body>
   </file>
 </xliff>

src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.ko.xlf

@@ -458,6 +458,11 @@ Actual: {2}</source>
         <target state="translated">CollectionAssert.ReferenceEquals는 Assertions에 사용할 수 없습니다. 대신 CollectionAssert 메서드 또는 Assert.AreSame 및 오버로드를 사용하세요.</target>
         <note></note>
       </trans-unit>
+      <trans-unit id="AssertScopeFailure">
+        <source>{0} assertion(s) failed within the assert scope:</source>
+        <target state="new">{0} assertion(s) failed within the assert scope:</target>
+        <note>{0} is the number of assertion failures collected in the scope.</note>
+      </trans-unit>
     </body>
   </file>
 </xliff>

src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.pl.xlf

@@ -458,6 +458,11 @@ Rzeczywiste: {2}</target>
         <target state="translated">Element Assert.ReferenceEquals nie powinien być używany dla asercji. Zamiast tego użyj metod CollectionAssert lub Assert.AreSame oraz ich przeciążeń.</target>
         <note></note>
       </trans-unit>
+      <trans-unit id="AssertScopeFailure">
+        <source>{0} assertion(s) failed within the assert scope:</source>
+        <target state="new">{0} assertion(s) failed within the assert scope:</target>
+        <note>{0} is the number of assertion failures collected in the scope.</note>
+      </trans-unit>
     </body>
   </file>
 </xliff>

src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.pt-BR.xlf

@@ -458,6 +458,11 @@ Real: {2}</target>
         <target state="translated">CollectionAssert.ReferenceEquals não deve ser usado com as Declarações. Em vez disso, use os métodos CollectionAssert ou Assert.AreSame e as sobrecargas.</target>
         <note></note>
       </trans-unit>
+      <trans-unit id="AssertScopeFailure">
+        <source>{0} assertion(s) failed within the assert scope:</source>
+        <target state="new">{0} assertion(s) failed within the assert scope:</target>
+        <note>{0} is the number of assertion failures collected in the scope.</note>
+      </trans-unit>
     </body>
   </file>
 </xliff>

src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.ru.xlf

@@ -458,6 +458,11 @@ Actual: {2}</source>
         <target state="translated">Нельзя использовать CollectionAssert.ReferenceEquals для Assertions. Вместо этого используйте методы CollectionAssert или Assert.AreSame и перегрузки.</target>
         <note></note>
       </trans-unit>
+      <trans-unit id="AssertScopeFailure">
+        <source>{0} assertion(s) failed within the assert scope:</source>
+        <target state="new">{0} assertion(s) failed within the assert scope:</target>
+        <note>{0} is the number of assertion failures collected in the scope.</note>
+      </trans-unit>
     </body>
   </file>
 </xliff>

src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.tr.xlf

@@ -458,6 +458,11 @@ Gerçekte olan: {2}</target>
         <target state="translated">CollectionAssert.ReferenceEquals, Onaylama için kullanılmamalı. Lütfen bunun yerine CollectionAssert yöntemlerini veya Assert.AreSame &amp; aşırı yüklemelerini kullanın.</target>
         <note></note>
       </trans-unit>
+      <trans-unit id="AssertScopeFailure">
+        <source>{0} assertion(s) failed within the assert scope:</source>
+        <target state="new">{0} assertion(s) failed within the assert scope:</target>
+        <note>{0} is the number of assertion failures collected in the scope.</note>
+      </trans-unit>
     </body>
   </file>
 </xliff>

src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.zh-Hans.xlf

@@ -458,6 +458,11 @@ Actual: {2}</source>
         <target state="translated">CollectionAssert.ReferenceEquals 不应用于断言。请改用 CollectionAssert 方法或 Assert.AreSame 和重载。</target>
         <note></note>
       </trans-unit>
+      <trans-unit id="AssertScopeFailure">
+        <source>{0} assertion(s) failed within the assert scope:</source>
+        <target state="new">{0} assertion(s) failed within the assert scope:</target>
+        <note>{0} is the number of assertion failures collected in the scope.</note>
+      </trans-unit>
     </body>
   </file>
 </xliff>

src/TestFramework/TestFramework/Resources/xlf/FrameworkMessages.zh-Hant.xlf

@@ -458,6 +458,11 @@ Actual: {2}</source>
         <target state="translated">CollectionAssert.ReferenceEquals 不應使用於判斷提示。請改用 CollectionAssert 方法或 Assert.AreSame 及其多載。</target>
         <note></note>
       </trans-unit>
+      <trans-unit id="AssertScopeFailure">
+        <source>{0} assertion(s) failed within the assert scope:</source>
+        <target state="new">{0} assertion(s) failed within the assert scope:</target>
+        <note>{0} is the number of assertion failures collected in the scope.</note>
+      </trans-unit>
     </body>
   </file>
 </xliff>