Add explicit testing of corner cases

Commit migrated from dotnet/corefx@7cc6531
kmett · Sep 11, 2018 · f253d35 · f253d35
1 parent b70b7d8
commit f253d35
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Showing 2 changed files with 73 additions and 4 deletions.
diff --git a/src/libraries/System.Runtime.Numerics/src/System/Numerics/Complex.cs b/src/libraries/System.Runtime.Numerics/src/System/Numerics/Complex.cs
@@ -178,6 +178,11 @@ public static Complex Divide(double dividend, Complex divisor)
             double c = right.m_real;
             double d = right.m_imaginary;
 
+            if (d == 0.0)
+            {
+                return left / c;
+            }
+
             // Computing c * c + d * d will overflow even in cases where the actual result of the division does not overflow.
             if (Math.Abs(d) < Math.Abs(c))
             {
@@ -203,6 +208,16 @@ public static Complex Divide(double dividend, Complex divisor)
             double c = right.m_real;
             double d = right.m_imaginary;
 
+            if (d == 0.0)
+            {
+                if (c == 0.0)
+                {
+                    return new Complex(left / c, left / c);
+                }
+
+                return left / c;
+            }
+
             // Computing c * c + d * d will overflow even in cases where the actual result of the division does not overflow.
             if (Math.Abs(d) < Math.Abs(c))
             {

diff --git a/src/libraries/System.Runtime.Numerics/tests/ComplexTests.cs b/src/libraries/System.Runtime.Numerics/tests/ComplexTests.cs
@@ -728,8 +728,7 @@ public static void Cosh_Legacy(double real, double imaginary, double expectedRea
         public static IEnumerable<object[]> Divide_TestData()
         {
             yield return new object[] { 0, 0, 10, 50 }; // 0 / x = 0
-            yield return new object[] { 10, 50, double.NaN, double.NaN }; // 0 / x = NaN
-            yield return new object[] { 10, 50, 0, 0 }; // x / 0 = 0
+            yield return new object[] { 10, 50, double.NaN, double.NaN }; // x / NaN = NaN
 
             yield return new object[] { 1, 0, 10, 50 }; // 1 / x = x
             yield return new object[] { 10, 50, 1, 0 }; // x / 1 = x
@@ -743,6 +742,13 @@ public static IEnumerable<object[]> Divide_TestData()
             yield return new object[] { double.MinValue, double.MinValue, SmallRandomPositiveDouble(), SmallRandomPositiveDouble() };
         }
 
+        public static IEnumerable<object[]> Divide_AdvancedTestData()
+        {
+            yield return new object[] { 10, 50, double.NaN, double.NaN, double.NaN, double.NaN }; // 0 / NaN = NaN
+            yield return new object[] { 10, 50, 0, 0, double.PositiveInfinity, double.PositiveInfinity }; // x / 0 = Inf
+            yield return new object[] { 0, 0, 0, 0, double.NaN, double.NaN }; // 0 / 0 = NaN
+        }
+
         [Theory]
         [MemberData(nameof(Divide_TestData))]
         [MemberData(nameof(SmallRandom_4_TestData))]
@@ -775,9 +781,25 @@ public static void Divide(double realLeft, double imaginaryLeft, double realRigh
         }
 
         [Theory]
-        //[MemberData(nameof(Divide_TestData))]
+        [MemberData(nameof(Divide_AdvancedTestData))]
+        public static void Divide_Advanced(double realLeft, double imaginaryLeft, double realRight, double imaginaryRight, double expectedReal, double expectedImaginary)
+        {
+            var dividend = new Complex(realLeft, imaginaryLeft);
+            var divisor = new Complex(realRight, imaginaryRight);
+
+            // Operator
+            Complex result = dividend / divisor;
+            VerifyRealImaginaryProperties(result, expectedReal, expectedImaginary);
+
+            // Static method
+            result = Complex.Divide(dividend, divisor);
+            VerifyRealImaginaryProperties(result, expectedReal, expectedImaginary);
+        }
+
+        [Theory]
+        [MemberData(nameof(Divide_TestData))]
         [MemberData(nameof(SmallRandom_4_TestData))]
-        //[MemberData(nameof(Invalid_4_TestData))]
+        [MemberData(nameof(Invalid_4_TestData))]
         public static void DivideByDouble(double realLeft, double imaginaryLeft, double realRight, double imaginaryRight)
         {
             var dividend = new Complex(realLeft, imaginaryLeft);
@@ -796,6 +818,22 @@ public static void DivideByDouble(double realLeft, double imaginaryLeft, double
             VerifyRealImaginaryProperties(result, expectedReal, expectedImaginary);
         }
 
+        [Theory]
+        [MemberData(nameof(Divide_AdvancedTestData))]
+        public static void DivideByDouble_Advanced(double realLeft, double imaginaryLeft, double realRight, double imaginaryRight, double expectedReal, double expectedImaginary)
+        {
+            var dividend = new Complex(realLeft, imaginaryLeft);
+            var divisor = realRight;
+
+            // Operator
+            Complex result = dividend / divisor;
+            VerifyRealImaginaryProperties(result, expectedReal, expectedImaginary);
+
+            // Static method
+            result = Complex.Divide(dividend, divisor);
+            VerifyRealImaginaryProperties(result, expectedReal, expectedImaginary);
+        }
+
         [Theory]
         [MemberData(nameof(Divide_TestData))]
         [MemberData(nameof(SmallRandom_4_TestData))]
@@ -818,6 +856,22 @@ public static void DivideByComplex(double realLeft, double imaginaryLeft, double
             VerifyRealImaginaryProperties(result, expectedReal, expectedImaginary);
         }
 
+        [Theory]
+        [MemberData(nameof(Divide_AdvancedTestData))]
+        public static void DivideByComplex_Advanced(double realLeft, double imaginaryLeft, double realRight, double imaginaryRight, double expectedReal, double expectedImaginary)
+        {
+            var dividend = realLeft;
+            var divisor = new Complex(realRight, imaginaryRight);
+
+            // Operator
+            Complex result = dividend / divisor;
+            VerifyRealImaginaryProperties(result, expectedReal, expectedImaginary);
+
+            // Static method
+            result = Complex.Divide(dividend, divisor);
+            VerifyRealImaginaryProperties(result, expectedReal, expectedImaginary);
+        }
+
         [Fact]
         [SkipOnTargetFramework(TargetFrameworkMonikers.NetFramework)]
         public static void Equals_netcore()