From dbb5cde3271617247fae1809e14ae1c283268acb Mon Sep 17 00:00:00 2001
From: Robert Coltheart <robert.coltheart@gmail.com>
Date: Sun, 31 May 2026 08:29:08 +1000
Subject: [PATCH 1/2] Add WasCalled to tunit mocks assertions

---
 TUnit.Mocks.Assertions/MockAssertionExtensions.cs | 10 ++++++++++
 TUnit.Mocks.Tests/AsyncVerificationTests.cs       | 14 ++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/TUnit.Mocks.Assertions/MockAssertionExtensions.cs b/TUnit.Mocks.Assertions/MockAssertionExtensions.cs
index 98dd817347..3fcccdbdd7 100644
--- a/TUnit.Mocks.Assertions/MockAssertionExtensions.cs
+++ b/TUnit.Mocks.Assertions/MockAssertionExtensions.cs
@@ -10,6 +10,16 @@ namespace TUnit.Mocks.Assertions;
 /// </summary>
 public static class MockAssertionExtensions
 {
+    /// <summary>
+    /// Asserts that the mock member was called at least once.
+    /// </summary>
+    public static WasCalledAssertion WasCalled(
+        this IAssertionSource<ICallVerification> source)
+    {
+        source.Context.ExpressionBuilder.Append($".WasCalled({nameof(Times.AtLeastOnce)})");
+        return new WasCalledAssertion(source.Context, Times.AtLeastOnce);
+    }
+
     /// <summary>
     /// Asserts that the mock member was called the specified number of times.
     /// </summary>
diff --git a/TUnit.Mocks.Tests/AsyncVerificationTests.cs b/TUnit.Mocks.Tests/AsyncVerificationTests.cs
index 055094109f..fecf6d6e0d 100644
--- a/TUnit.Mocks.Tests/AsyncVerificationTests.cs
+++ b/TUnit.Mocks.Tests/AsyncVerificationTests.cs
@@ -84,6 +84,20 @@ await Assert.That(mock.Add(Any(), Any()))
             .WasCalled(Times.AtLeastOnce);
     }
 
+    [Test]
+    public async Task WasCalled_AtLeastOnceByDefault_Passes()
+    {
+        var mock = ICalculator.Mock();
+        mock.Add(Any(), Any()).Returns(42);
+
+        ICalculator calc = mock.Object;
+        _ = calc.Add(1, 2);
+        _ = calc.Add(3, 4);
+
+        await Assert.That(mock.Add(Any(), Any()))
+            .WasCalled();
+    }
+
     [Test]
     public async Task Property_Getter_WasCalled_Via_Assert()
     {

From fb248187461eb3a7da24b1b36baf3243eef95414 Mon Sep 17 00:00:00 2001
From: Tom Longhurst <30480171+thomhurst@users.noreply.github.com>
Date: Sun, 31 May 2026 15:20:10 +0100
Subject: [PATCH 2/2] refactor(assertions): generate WasCalled() via
 [GenerateAssertion]

Replace the hand-written parameterless WasCalled() extension with a
[GenerateAssertion]-decorated method, per the project's preference for
generated assertions.

The previous manual overload targeted IAssertionSource<ICallVerification>
directly, which does not bind to the concrete IAssertionSource<TMockCall>
produced by Assert.That(mock.Method()) (IAssertionSource is invariant), so
the WasCalled() call site did not compile. The generated covariant form
WasCalled<TActual>(this IAssertionSource<TActual>) where TActual : ICallVerification
binds correctly.

- Declare the source method as a non-extension static so the generator
  emits a static-qualified call, avoiding the name clash with the void
  ICallVerification.WasCalled() instance method.
- Reference TUnit.Assertions.SourceGenerator as an analyzer (it does not
  flow transitively through the TUnit.Assertions project reference).
- Add a failing-path test for the parameterless WasCalled().
---
 .../MockAssertionExtensions.cs                | 23 +++++++++++++++----
 .../TUnit.Mocks.Assertions.csproj             |  1 +
 TUnit.Mocks.Tests/AsyncVerificationTests.cs   | 10 ++++++++
 3 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/TUnit.Mocks.Assertions/MockAssertionExtensions.cs b/TUnit.Mocks.Assertions/MockAssertionExtensions.cs
index 3fcccdbdd7..a9214990aa 100644
--- a/TUnit.Mocks.Assertions/MockAssertionExtensions.cs
+++ b/TUnit.Mocks.Assertions/MockAssertionExtensions.cs
@@ -1,5 +1,7 @@
 using System.Runtime.CompilerServices;
+using TUnit.Assertions.Attributes;
 using TUnit.Assertions.Core;
+using TUnit.Mocks.Exceptions;
 using TUnit.Mocks.Verification;
 
 namespace TUnit.Mocks.Assertions;
@@ -12,12 +14,25 @@ public static class MockAssertionExtensions
 {
     /// <summary>
     /// Asserts that the mock member was called at least once.
+    /// Generates the <c>WasCalled()</c> assertion on <see cref="IAssertionSource{ICallVerification}"/>.
     /// </summary>
-    public static WasCalledAssertion WasCalled(
-        this IAssertionSource<ICallVerification> source)
+    [GenerateAssertion(ExpectationMessage = "to have been called")]
+    public static AssertionResult WasCalled(ICallVerification verification)
     {
-        source.Context.ExpressionBuilder.Append($".WasCalled({nameof(Times.AtLeastOnce)})");
-        return new WasCalledAssertion(source.Context, Times.AtLeastOnce);
+        if (verification is null)
+        {
+            return AssertionResult.Failed("Verification target is null");
+        }
+
+        try
+        {
+            verification.WasCalled();
+            return AssertionResult.Passed;
+        }
+        catch (MockVerificationException ex)
+        {
+            return AssertionResult.Failed(ex.Message);
+        }
     }
 
     /// <summary>
diff --git a/TUnit.Mocks.Assertions/TUnit.Mocks.Assertions.csproj b/TUnit.Mocks.Assertions/TUnit.Mocks.Assertions.csproj
index ec69d4e884..e0deaada1f 100644
--- a/TUnit.Mocks.Assertions/TUnit.Mocks.Assertions.csproj
+++ b/TUnit.Mocks.Assertions/TUnit.Mocks.Assertions.csproj
@@ -9,6 +9,7 @@
     <ItemGroup>
         <ProjectReference Include="..\TUnit.Mocks\TUnit.Mocks.csproj" />
         <ProjectReference Include="..\TUnit.Assertions\TUnit.Assertions.csproj" />
+        <ProjectReference Include="..\TUnit.Assertions.SourceGenerator\TUnit.Assertions.SourceGenerator.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" />
     </ItemGroup>
 
     <Import Project="..\Library.targets" />
diff --git a/TUnit.Mocks.Tests/AsyncVerificationTests.cs b/TUnit.Mocks.Tests/AsyncVerificationTests.cs
index fecf6d6e0d..af4b6974d0 100644
--- a/TUnit.Mocks.Tests/AsyncVerificationTests.cs
+++ b/TUnit.Mocks.Tests/AsyncVerificationTests.cs
@@ -98,6 +98,16 @@ await Assert.That(mock.Add(Any(), Any()))
             .WasCalled();
     }
 
+    [Test]
+    public async Task WasCalled_Default_Fails_When_Not_Called()
+    {
+        var mock = ICalculator.Mock();
+
+        await Assert.ThrowsAsync(async () =>
+            await Assert.That(mock.Add(Any(), Any()))
+                .WasCalled());
+    }
+
     [Test]
     public async Task Property_Getter_WasCalled_Via_Assert()
     {