From d6336dcb04bf24bf7e15ad92cdddcdbfc24664a2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Valentin=20Breu=C3=9F?= <vbreuss@gmail.com>
Date: Sat, 17 Jan 2026 06:24:23 +0100
Subject: [PATCH 1/2] fix: throw `ArgumentOutOfRangeException` when times of
 `For` is not positive

---
 Source/Mockolate/Setup/Callback.cs            | 10 +++-
 .../SetupMethodTests.CallbackTests.cs         | 51 +++++++++++++++++++
 .../SetupPropertyTests.OnGetTests.cs          | 17 +++++++
 3 files changed, 77 insertions(+), 1 deletion(-)

diff --git a/Source/Mockolate/Setup/Callback.cs b/Source/Mockolate/Setup/Callback.cs
index 500821c1..9b4ac1ac 100644
--- a/Source/Mockolate/Setup/Callback.cs
+++ b/Source/Mockolate/Setup/Callback.cs
@@ -54,7 +54,15 @@ public void When(Func<int, bool> predicate)
 	///     to <see langword="true" />).
 	/// </remarks>
 	public void For(int times)
-		=> _forTimes = times;
+	{
+		if (times <= 0)
+		{
+			// ReSharper disable once LocalizableElement
+			throw new ArgumentOutOfRangeException(nameof(times), "Times must be greater than zero.");
+		}
+
+		_forTimes = times;
+	}
 
 	/// <summary>
 	///     Deactivates the callback after it was invoked the given number of <paramref name="times" />.
diff --git a/Tests/Mockolate.Tests/MockMethods/SetupMethodTests.CallbackTests.cs b/Tests/Mockolate.Tests/MockMethods/SetupMethodTests.CallbackTests.cs
index d7f6f52c..bb2919c1 100644
--- a/Tests/Mockolate.Tests/MockMethods/SetupMethodTests.CallbackTests.cs
+++ b/Tests/Mockolate.Tests/MockMethods/SetupMethodTests.CallbackTests.cs
@@ -319,6 +319,40 @@ public async Task CallbackWithValue_ShouldNotExecuteWhenParameterDoesNotMatch()
 				await That(callCount).IsEqualTo(0);
 			}
 
+			[Theory]
+			[InlineData(-2)]
+			[InlineData(0)]
+			public async Task For_LessThanOne_ShouldThrowArgumentOutOfRangeException(int times)
+			{
+				IReturnMethodSetupTest sut = Mock.Create<IReturnMethodSetupTest>();
+
+				void Act()
+				{
+					sut.SetupMock.Method.Method1(It.IsAny<int>())
+						.Returns("").For(times);
+				}
+
+				await That(Act).Throws<ArgumentOutOfRangeException>()
+					.WithMessage("Times must be greater than zero.").AsPrefix();
+			}
+
+			[Fact]
+			public async Task For_NegativeOrNull_ShouldThrowArgumentOutOfRangeException()
+			{
+				List<int> invocations = [];
+				IReturnMethodSetupTest sut = Mock.Create<IReturnMethodSetupTest>();
+				sut.SetupMock.Method.Method1(It.IsAny<int>())
+					.Do((i, _) => { invocations.Add(i); })
+					.For(4);
+
+				for (int i = 0; i < 20; i++)
+				{
+					sut.Method1(i);
+				}
+
+				await That(invocations).IsEqualTo([0, 1, 2, 3,]);
+			}
+
 			[Fact]
 			public async Task For_ShouldStopExecutingCallbackAfterTheGivenTimes()
 			{
@@ -377,6 +411,23 @@ public async Task InParallel_ShouldInvokeParallelCallbacksAlways()
 				await That(callCount3).IsEqualTo(6);
 			}
 
+			[Theory]
+			[InlineData(-2)]
+			[InlineData(0)]
+			public async Task Only_LessThanOne_ShouldThrowArgumentOutOfRangeException(int times)
+			{
+				IReturnMethodSetupTest sut = Mock.Create<IReturnMethodSetupTest>();
+
+				void Act()
+				{
+					sut.SetupMock.Method.Method1(It.IsAny<int>())
+						.Returns("").Only(times);
+				}
+
+				await That(Act).Throws<ArgumentOutOfRangeException>()
+					.WithMessage("Times must be greater than zero.").AsPrefix();
+			}
+
 			[Theory]
 			[InlineData(1, 1)]
 			[InlineData(2, 3)]
diff --git a/Tests/Mockolate.Tests/MockProperties/SetupPropertyTests.OnGetTests.cs b/Tests/Mockolate.Tests/MockProperties/SetupPropertyTests.OnGetTests.cs
index 704cfbe5..7ce94dc5 100644
--- a/Tests/Mockolate.Tests/MockProperties/SetupPropertyTests.OnGetTests.cs
+++ b/Tests/Mockolate.Tests/MockProperties/SetupPropertyTests.OnGetTests.cs
@@ -24,6 +24,23 @@ public async Task For_ShouldStopExecutingCallbackAfterTheGivenTimes()
 			await That(invocations).IsEqualTo([0, 1, 2, 3,]);
 		}
 
+		[Theory]
+		[InlineData(-2)]
+		[InlineData(0)]
+		public async Task For_LessThanOne_ShouldThrowArgumentOutOfRangeException(int times)
+		{
+			IPropertyService sut = Mock.Create<IPropertyService>();
+
+			void Act()
+			{
+				sut.SetupMock.Property.MyProperty
+					.OnGet.Do(() => { }).For(times);
+			}
+
+			await That(Act).Throws<ArgumentOutOfRangeException>()
+				.WithMessage("Times must be greater than zero.").AsPrefix();
+		}
+
 		[Fact]
 		public async Task For_WithWhen_ShouldStopExecutingCallbackAfterTheGivenTimes()
 		{

From 8446014d3bf1ee794158cbefff38d7b1aaa56f22 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Valentin=20Breu=C3=9F?= <vbreuss@gmail.com>
Date: Sat, 17 Jan 2026 07:31:56 +0100
Subject: [PATCH 2/2] Fix review issue

---
 .../SetupMethodTests.CallbackTests.cs           | 17 -----------------
 1 file changed, 17 deletions(-)

diff --git a/Tests/Mockolate.Tests/MockMethods/SetupMethodTests.CallbackTests.cs b/Tests/Mockolate.Tests/MockMethods/SetupMethodTests.CallbackTests.cs
index bb2919c1..d0ba2019 100644
--- a/Tests/Mockolate.Tests/MockMethods/SetupMethodTests.CallbackTests.cs
+++ b/Tests/Mockolate.Tests/MockMethods/SetupMethodTests.CallbackTests.cs
@@ -336,23 +336,6 @@ await That(Act).Throws<ArgumentOutOfRangeException>()
 					.WithMessage("Times must be greater than zero.").AsPrefix();
 			}
 
-			[Fact]
-			public async Task For_NegativeOrNull_ShouldThrowArgumentOutOfRangeException()
-			{
-				List<int> invocations = [];
-				IReturnMethodSetupTest sut = Mock.Create<IReturnMethodSetupTest>();
-				sut.SetupMock.Method.Method1(It.IsAny<int>())
-					.Do((i, _) => { invocations.Add(i); })
-					.For(4);
-
-				for (int i = 0; i < 20; i++)
-				{
-					sut.Method1(i);
-				}
-
-				await That(invocations).IsEqualTo([0, 1, 2, 3,]);
-			}
-
 			[Fact]
 			public async Task For_ShouldStopExecutingCallbackAfterTheGivenTimes()
 			{