Add comprehensive IsPrime tests

X10D.Tests/src/Math/IsPrimeTests.cs

@@ -24,8 +24,40 @@ public class IsPrimeTests
         for (var index = 0; index < _primeNumbers.Count; index++)
         {
             int value = _primeNumbers[index];
-            bool result = value.IsPrime();
-            Assert.IsTrue(result, value.ToString("N0", CultureInfo.InvariantCulture));
+
+            Assert.IsTrue(value.IsPrime());
+            Assert.IsTrue(((long)value).IsPrime());
+
+            if (value is >= byte.MinValue and <= byte.MaxValue)
+            {
+                Assert.IsTrue(((byte)value).IsPrime());
+            }
+
+            if (value is >= short.MinValue and <= short.MaxValue)
+            {
+                Assert.IsTrue(((short)value).IsPrime());
+            }
+
+            if (value is >= byte.MinValue and <= byte.MaxValue)
+            {
+                Assert.IsTrue(((byte)value).IsPrime());
+            }
+
+            if (value is >= ushort.MinValue and <= ushort.MaxValue)
+            {
+                Assert.IsTrue(((ushort)value).IsPrime());
+            }
+
+            if (value is >= sbyte.MinValue and <= sbyte.MaxValue)
+            {
+                Assert.IsTrue(((sbyte)value).IsPrime());
+            }
+
+            if (value >= 0)
+            {
+                Assert.IsTrue(((uint)value).IsPrime());
+                Assert.IsTrue(((ulong)value).IsPrime());
+            }
         }
     }
 
@@ -34,8 +66,14 @@ public class IsPrimeTests
     {
         for (var value = short.MinValue; value < 0; value++)
         {
-            bool result = value.IsPrime();
-            Assert.IsFalse(result, value.ToString("N0", CultureInfo.InvariantCulture));
+            Assert.IsFalse(value.IsPrime());
+            Assert.IsFalse(((int)value).IsPrime());
+            Assert.IsFalse(((long)value).IsPrime());
+
+            if (value is >= sbyte.MinValue and <= sbyte.MaxValue)
+            {
+                Assert.IsFalse(((sbyte)value).IsPrime());
+            }
         }
     }
 
@@ -44,8 +82,15 @@ public class IsPrimeTests
     {
         for (var value = 0; value < 2; value++)
         {
-            bool result = value.IsPrime();
-            Assert.IsFalse(result, value.ToString("N0", CultureInfo.InvariantCulture));
+            Assert.IsFalse(value.IsPrime());
+            Assert.IsFalse(((byte)value).IsPrime());
+            Assert.IsFalse(((short)value).IsPrime());
+            Assert.IsFalse(((long)value).IsPrime());
+
+            Assert.IsFalse(((sbyte)value).IsPrime());
+            Assert.IsFalse(((ushort)value).IsPrime());
+            Assert.IsFalse(((uint)value).IsPrime());
+            Assert.IsFalse(((ulong)value).IsPrime());
         }
     }
 
@@ -55,9 +100,14 @@ public class IsPrimeTests
         for (var value = 0; value < 7920; value++)
         {
             bool expected = _primeNumbers.Contains(value);
-            bool actual = value.IsPrime();
 
-            Assert.AreEqual(expected, actual, value.ToString("N0", CultureInfo.InvariantCulture));
+            Assert.AreEqual(expected, ((short)value).IsPrime());
+            Assert.AreEqual(expected, value.IsPrime());
+            Assert.AreEqual(expected, ((long)value).IsPrime());
+
+            Assert.AreEqual(expected, ((ushort)value).IsPrime());
+            Assert.AreEqual(expected, ((uint)value).IsPrime());
+            Assert.AreEqual(expected, ((ulong)value).IsPrime());
         }
     }
 
@@ -67,9 +117,20 @@ public class IsPrimeTests
         for (byte value = 0; value < byte.MaxValue; value++)
         {
             bool expected = _primeNumbers.Contains(value);
-            bool actual = value.IsPrime();
 
-            Assert.AreEqual(expected, actual, value.ToString("N0", CultureInfo.InvariantCulture));
+            Assert.AreEqual(expected, value.IsPrime());
+            Assert.AreEqual(expected, ((short)value).IsPrime());
+            Assert.AreEqual(expected, ((int)value).IsPrime());
+            Assert.AreEqual(expected, ((long)value).IsPrime());
+
+            Assert.AreEqual(expected, ((ushort)value).IsPrime());
+            Assert.AreEqual(expected, ((uint)value).IsPrime());
+            Assert.AreEqual(expected, ((ulong)value).IsPrime());
+
+            if (value < sbyte.MaxValue)
+            {
+                Assert.AreEqual(expected, ((sbyte)value).IsPrime());
+            }
         }
     }
 

X10D/src/Math/UInt16Extensions.cs

@@ -1,4 +1,4 @@
-using System.Diagnostics.Contracts;
+using System.Diagnostics.Contracts;
 using System.Runtime.CompilerServices;
 
 namespace X10D.Math;
@@ -62,6 +62,20 @@ public static class UInt16Extensions
         return (value & 1) == 0;
     }
 
+    /// <summary>
+    ///     Returns a value indicating whether the current value is a prime number.
+    /// </summary>
+    /// <param name="value">The value whose primality to check.</param>
+    /// <returns>
+    ///     <see langword="true" /> if <paramref name="value" /> is prime; otherwise, <see langword="false" />.
+    /// </returns>
+    [Pure]
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+    public static bool IsPrime(this ushort value)
+    {
+        return ((ulong)value).IsPrime();
+    }
+
     /// <summary>
     ///     Returns a value indicating whether the current value is not evenly divisible by 2.
     /// </summary>

X10D/src/Math/UInt32Extensions.cs

@@ -1,4 +1,4 @@
-using System.Diagnostics.Contracts;
+using System.Diagnostics.Contracts;
 using System.Runtime.CompilerServices;
 
 namespace X10D.Math;
@@ -62,6 +62,20 @@ public static class UInt32Extensions
         return (value & 1) == 0;
     }
 
+    /// <summary>
+    ///     Returns a value indicating whether the current value is a prime number.
+    /// </summary>
+    /// <param name="value">The value whose primality to check.</param>
+    /// <returns>
+    ///     <see langword="true" /> if <paramref name="value" /> is prime; otherwise, <see langword="false" />.
+    /// </returns>
+    [Pure]
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+    public static bool IsPrime(this uint value)
+    {
+        return ((ulong)value).IsPrime();
+    }
+
     /// <summary>
     ///     Returns a value indicating whether the current value is not evenly divisible by 2.
     /// </summary>

X10D/src/Math/UInt64Extensions.cs

@@ -1,4 +1,4 @@
-using System.Diagnostics.Contracts;
+using System.Diagnostics.Contracts;
 using System.Runtime.CompilerServices;
 
 namespace X10D.Math;
@@ -62,6 +62,45 @@ public static class UInt64Extensions
         return (value & 1) == 0;
     }
 
+    /// <summary>
+    ///     Returns a value indicating whether the current value is a prime number.
+    /// </summary>
+    /// <param name="value">The value whose primality to check.</param>
+    /// <returns>
+    ///     <see langword="true" /> if <paramref name="value" /> is prime; otherwise, <see langword="false" />.
+    /// </returns>
+    [Pure]
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+    public static bool IsPrime(this ulong value)
+    {
+        switch (value)
+        {
+            case < 2: return false;
+            case 2:
+            case 3: return true;
+        }
+
+        if (value % 2 == 0 || value % 3 == 0)
+        {
+            return false;
+        }
+
+        if ((value + 1) % 6 != 0 && (value - 1) % 6 != 0)
+        {
+            return false;
+        }
+
+        for (var iterator = 5UL; iterator * iterator <= value; iterator += 6)
+        {
+            if (value % iterator == 0 || value % (iterator + 2) == 0)
+            {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
     /// <summary>
     ///     Returns a value indicating whether the current value is not evenly divisible by 2.
     /// </summary>