feat: add DecimalEqualsAssertion for decimal comparisons with tolerance

TUnit.Assertions.Tests/Old/DecimalEqualsToAssertionTests.cs

@@ -24,19 +24,19 @@ public async Task Decimal_EqualsTo_Failure()
     [Test]
     public async Task Decimal_EqualsTo__With_Tolerance_Success()
     {
-        var double1 = 1.0001d;
-        var double2 = 1.0002d;
-        
-        await TUnitAssert.That(double1).IsEqualTo(double2).Within(0.0001);
+        var decimal1 = 1.0001m;
+        var decimal2 = 1.0002m;
+
+        await TUnitAssert.That(decimal1).IsEqualTo(decimal2).Within(0.0001m);
     }
-    
+
     [Test]
     public async Task Decimal_EqualsTo__With_Tolerance_Failure()
     {
-        var double1 = 1.0001d;
-        var double2 = 1.0003d;
-        
-        await TUnitAssert.ThrowsAsync<TUnitAssertionException>(async () => await TUnitAssert.That(double1).IsEqualTo(double2).Within(0.0001));
+        var decimal1 = 1.0001m;
+        var decimal2 = 1.0003m;
+
+        await TUnitAssert.ThrowsAsync<TUnitAssertionException>(async () => await TUnitAssert.That(decimal1).IsEqualTo(decimal2).Within(0.0001m));
     }
 #endif
 }

TUnit.Assertions/Conditions/SpecializedEqualityAssertions.cs

@@ -309,6 +309,41 @@ protected override bool AreExactlyEqual(long actual, long expected)
     }
 }
 
+/// <summary>
+/// Asserts that a decimal value is equal to another, with optional tolerance.
+/// </summary>
+[AssertionExtension("IsEqualTo", OverloadResolutionPriority = 2)]
+public class DecimalEqualsAssertion : ToleranceBasedEqualsAssertion<decimal, decimal>
+{
+    public DecimalEqualsAssertion(
+        AssertionContext<decimal> context,
+        decimal expected)
+        : base(context, expected)
+    {
+    }
+
+    protected override bool HasToleranceValue()
+    {
+        return true; // decimal? always has meaningful value when not null
+    }
+
+    protected override bool IsWithinTolerance(decimal actual, decimal expected, decimal tolerance)
+    {
+        var diff = Math.Abs(actual - expected);
+        return diff <= tolerance;
+    }
+
+    protected override object CalculateDifference(decimal actual, decimal expected)
+    {
+        return Math.Abs(actual - expected);
+    }
+
+    protected override bool AreExactlyEqual(decimal actual, decimal expected)
+    {
+        return actual == expected;
+    }
+}
+
 /// <summary>
 /// Asserts that a DateTimeOffset value is equal to another, with optional tolerance.
 /// </summary>

TUnit.PublicAPI/Tests.Assertions_Library_Has_No_API_Changes.DotNet10_0.verified.txt

@@ -677,6 +677,15 @@ namespace .Conditions
         [.(ExpectationMessage="to be a weekend day")]
         public static bool IsWeekend(this  value) { }
     }
+    [.("IsEqualTo", OverloadResolutionPriority=2)]
+    public class DecimalEqualsAssertion : .<decimal, decimal>
+    {
+        public DecimalEqualsAssertion(.<decimal> context, decimal expected) { }
+        protected override bool AreExactlyEqual(decimal actual, decimal expected) { }
+        protected override object CalculateDifference(decimal actual, decimal expected) { }
+        protected override bool HasToleranceValue() { }
+        protected override bool IsWithinTolerance(decimal actual, decimal expected, decimal tolerance) { }
+    }
     public class DictionaryContainsKeyAssertion<TDictionary, TKey, TValue> : .<TDictionary, TKey, TValue>
         where TDictionary : .<TKey, TValue>
     {
@@ -2500,6 +2509,11 @@ namespace .Extensions
         protected override .<.> CheckAsync(.<> metadata) { }
         protected override string GetExpectation() { }
     }
+    public static class DecimalEqualsAssertionExtensions
+    {
+        [.(2)]
+        public static . IsEqualTo(this .<decimal> source, decimal expected, [.("expected")] string? expectedExpression = null) { }
+    }
     public static class DirectoryHasFilesAssertionExtensions
     {
         public static . HasFiles(this .<.DirectoryInfo> source) { }

TUnit.PublicAPI/Tests.Assertions_Library_Has_No_API_Changes.DotNet8_0.verified.txt

@@ -674,6 +674,15 @@ namespace .Conditions
         [.(ExpectationMessage="to be a weekend day")]
         public static bool IsWeekend(this  value) { }
     }
+    [.("IsEqualTo", OverloadResolutionPriority=2)]
+    public class DecimalEqualsAssertion : .<decimal, decimal>
+    {
+        public DecimalEqualsAssertion(.<decimal> context, decimal expected) { }
+        protected override bool AreExactlyEqual(decimal actual, decimal expected) { }
+        protected override object CalculateDifference(decimal actual, decimal expected) { }
+        protected override bool HasToleranceValue() { }
+        protected override bool IsWithinTolerance(decimal actual, decimal expected, decimal tolerance) { }
+    }
     public class DictionaryContainsKeyAssertion<TDictionary, TKey, TValue> : .<TDictionary, TKey, TValue>
         where TDictionary : .<TKey, TValue>
     {
@@ -2494,6 +2503,10 @@ namespace .Extensions
         protected override .<.> CheckAsync(.<> metadata) { }
         protected override string GetExpectation() { }
     }
+    public static class DecimalEqualsAssertionExtensions
+    {
+        public static . IsEqualTo(this .<decimal> source, decimal expected, [.("expected")] string? expectedExpression = null) { }
+    }
     public static class DirectoryHasFilesAssertionExtensions
     {
         public static . HasFiles(this .<.DirectoryInfo> source) { }

TUnit.PublicAPI/Tests.Assertions_Library_Has_No_API_Changes.DotNet9_0.verified.txt

@@ -677,6 +677,15 @@ namespace .Conditions
         [.(ExpectationMessage="to be a weekend day")]
         public static bool IsWeekend(this  value) { }
     }
+    [.("IsEqualTo", OverloadResolutionPriority=2)]
+    public class DecimalEqualsAssertion : .<decimal, decimal>
+    {
+        public DecimalEqualsAssertion(.<decimal> context, decimal expected) { }
+        protected override bool AreExactlyEqual(decimal actual, decimal expected) { }
+        protected override object CalculateDifference(decimal actual, decimal expected) { }
+        protected override bool HasToleranceValue() { }
+        protected override bool IsWithinTolerance(decimal actual, decimal expected, decimal tolerance) { }
+    }
     public class DictionaryContainsKeyAssertion<TDictionary, TKey, TValue> : .<TDictionary, TKey, TValue>
         where TDictionary : .<TKey, TValue>
     {
@@ -2500,6 +2509,11 @@ namespace .Extensions
         protected override .<.> CheckAsync(.<> metadata) { }
         protected override string GetExpectation() { }
     }
+    public static class DecimalEqualsAssertionExtensions
+    {
+        [.(2)]
+        public static . IsEqualTo(this .<decimal> source, decimal expected, [.("expected")] string? expectedExpression = null) { }
+    }
     public static class DirectoryHasFilesAssertionExtensions
     {
         public static . HasFiles(this .<.DirectoryInfo> source) { }

TUnit.PublicAPI/Tests.Assertions_Library_Has_No_API_Changes.Net4_7.verified.txt

@@ -637,6 +637,15 @@ namespace .Conditions
         [.(ExpectationMessage="to be a weekend day")]
         public static bool IsWeekend(this  value) { }
     }
+    [.("IsEqualTo", OverloadResolutionPriority=2)]
+    public class DecimalEqualsAssertion : .<decimal, decimal>
+    {
+        public DecimalEqualsAssertion(.<decimal> context, decimal expected) { }
+        protected override bool AreExactlyEqual(decimal actual, decimal expected) { }
+        protected override object CalculateDifference(decimal actual, decimal expected) { }
+        protected override bool HasToleranceValue() { }
+        protected override bool IsWithinTolerance(decimal actual, decimal expected, decimal tolerance) { }
+    }
     public class DictionaryContainsKeyAssertion<TDictionary, TKey, TValue> : .<TDictionary, TKey, TValue>
         where TDictionary : .<TKey, TValue>
     {
@@ -2299,6 +2308,10 @@ namespace .Extensions
         protected override .<.> CheckAsync(.<> metadata) { }
         protected override string GetExpectation() { }
     }
+    public static class DecimalEqualsAssertionExtensions
+    {
+        public static . IsEqualTo(this .<decimal> source, decimal expected, [.("expected")] string? expectedExpression = null) { }
+    }
     public static class DirectoryHasFilesAssertionExtensions
     {
         public static . HasFiles(this .<.DirectoryInfo> source) { }