Add MROUND exception when number and multiple parameters have differe…

…nt signs
ClosedXML · Nov 21, 2020 · 5d2f462 · 5d2f462
1 parent 55c44a7
commit 5d2f462
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Showing 2 changed files with 13 additions and 3 deletions.
diff --git a/ClosedXML/Excel/CalcEngine/Functions/MathTrig.cs b/ClosedXML/Excel/CalcEngine/Functions/MathTrig.cs
@@ -763,10 +763,13 @@ private static object Mod(List<Expression> p)
 
         private static object MRound(List<Expression> p)
         {
-            var n = (Double)p[0];
-            var k = (Double)p[1];
+            var number = (Double)p[0];
+            var multiple = (Double)p[1];
 
-            return Math.Round(n / k, MidpointRounding.AwayFromZero) * k;
+            if (Math.Sign(number) != Math.Sign(multiple))
+                throw new NumberException($"The Number and Multiple arguments must have the same sign.");
+
+            return Math.Round(number / multiple, MidpointRounding.AwayFromZero) * multiple;
         }
 
         private static object Multinomial(List<Expression> p)

diff --git a/ClosedXML_Tests/Excel/CalcEngine/MathTrigTests.cs b/ClosedXML_Tests/Excel/CalcEngine/MathTrigTests.cs
@@ -1067,6 +1067,13 @@ public double MRound(double number, double multiple)
             return (double)XLWorkbook.EvaluateExpr($"MROUND({number}, {multiple})");
         }
 
+        [TestCase(123456.123, -10)]
+        [TestCase(-123456.123, 5)]
+        public void MRoundExceptions(double number, double multiple)
+        {
+            Assert.Throws<NumberException>(() => XLWorkbook.EvaluateExpr($"MROUND({number}, {multiple})"));
+        }
+
         [TestCase(0, 1)]
         [TestCase(0.3, 1.0467516)]
         [TestCase(0.6, 1.21162831)]