Merge pull request #4327 from Sergio0694/bugfix/incorrect-notnullorempty-exception

Fixed exception type for Guard.IsNotNullOr[Empty|WhiteSpace]

Author: michael-hawker

Microsoft.Toolkit.Diagnostics/Guard.String.cs

@@ -37,7 +37,8 @@ public static void IsNullOrEmpty(string? text, string name)
         /// </summary>
         /// <param name="text">The input <see cref="string"/> instance to test.</param>
         /// <param name="name">The name of the input parameter being tested.</param>
-        /// <exception cref="ArgumentException">Thrown if <paramref name="text"/> is <see langword="null"/> or empty.</exception>
+        /// <exception cref="ArgumentNullException">Thrown if <paramref name="text"/> is <see langword="null"/>.</exception>
+        /// <exception cref="ArgumentException">Thrown if <paramref name="text"/> is empty.</exception>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static void IsNotNullOrEmpty([NotNull] string? text, string name)
         {
@@ -89,7 +90,8 @@ public static void IsNullOrWhitespace(string? text, string name)
         /// </summary>
         /// <param name="text">The input <see cref="string"/> instance to test.</param>
         /// <param name="name">The name of the input parameter being tested.</param>
-        /// <exception cref="ArgumentException">Thrown if <paramref name="text"/> is <see langword="null"/> or whitespace.</exception>
+        /// <exception cref="ArgumentNullException">Thrown if <paramref name="text"/> is <see langword="null"/>.</exception>
+        /// <exception cref="ArgumentException">Thrown if <paramref name="text"/> is whitespace.</exception>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static void IsNotNullOrWhiteSpace([NotNull] string? text, string name)
         {

Microsoft.Toolkit.Diagnostics/Internals/Guard.String.ThrowHelper.cs

@@ -4,6 +4,7 @@
 
 using System;
 using System.Diagnostics.CodeAnalysis;
+using System.Runtime.CompilerServices;
 
 namespace Microsoft.Toolkit.Diagnostics
 {
@@ -27,12 +28,23 @@ public static void ThrowArgumentExceptionForIsNullOrEmpty(string? text, string n
             }
 
             /// <summary>
-            /// Throws an <see cref="ArgumentException"/> when <see cref="Guard.IsNotNullOrEmpty"/> fails.
+            /// Throws an <see cref="ArgumentNullException"/> or <see cref="ArgumentException"/> when <see cref="Guard.IsNotNullOrEmpty"/> fails.
             /// </summary>
             [DoesNotReturn]
             public static void ThrowArgumentExceptionForIsNotNullOrEmpty(string? text, string name)
             {
-                throw new ArgumentException($"Parameter {AssertString(name)} (string) must not be null or empty, was {(text is null ? "null" : "empty")}", name);
+                [MethodImpl(MethodImplOptions.NoInlining)]
+                static Exception GetException(string? text, string name)
+                {
+                    if (text is null)
+                    {
+                        return new ArgumentNullException(name, $"Parameter {AssertString(name)} (string) must not be null or empty, was null");
+                    }
+
+                    return new ArgumentException($"Parameter {AssertString(name)} (string) must not be null or empty, was empty", name);
+                }
+
+                throw GetException(text, name);
             }
 
             /// <summary>
@@ -50,7 +62,18 @@ public static void ThrowArgumentExceptionForIsNullOrWhiteSpace(string? text, str
             [DoesNotReturn]
             public static void ThrowArgumentExceptionForIsNotNullOrWhiteSpace(string? text, string name)
             {
-                throw new ArgumentException($"Parameter {AssertString(name)} (string) must not be null or whitespace, was {(text is null ? "null" : "whitespace")}", name);
+                [MethodImpl(MethodImplOptions.NoInlining)]
+                static Exception GetException(string? text, string name)
+                {
+                    if (text is null)
+                    {
+                        return new ArgumentNullException(name, $"Parameter {AssertString(name)} (string) must not be null or whitespace, was null");
+                    }
+
+                    return new ArgumentException($"Parameter {AssertString(name)} (string) must not be null or whitespace, was whitespace", name);
+                }
+
+                throw GetException(text, name);
             }
 
             /// <summary>

UnitTests/UnitTests.Shared/Diagnostics/Test_Guard.cs

@@ -121,6 +121,68 @@ public void Test_Guard_IsAssignableToType_Fail()
             Guard.IsAssignableToType(7, typeof(string), nameof(Test_Guard_IsAssignableToType_Fail));
         }
 
+        [TestCategory("Guard")]
+        [TestMethod]
+        public void Test_Guard_IsNullOrEmpty_Ok()
+        {
+            Guard.IsNullOrEmpty(null, nameof(Test_Guard_IsNullOrEmpty_Ok));
+            Guard.IsNullOrEmpty(string.Empty, nameof(Test_Guard_IsNullOrEmpty_Ok));
+        }
+
+        [TestCategory("Guard")]
+        [TestMethod]
+        [ExpectedException(typeof(ArgumentException))]
+        public void Test_Guard_IsNullOrEmpty_Fail()
+        {
+            Guard.IsNullOrEmpty("Hello", nameof(Test_Guard_IsNullOrEmpty_Fail));
+        }
+
+        [TestCategory("Guard")]
+        [TestMethod]
+        public void Test_Guard_IsNotNullOrEmpty_Ok()
+        {
+            Guard.IsNotNullOrEmpty("Hello", nameof(Test_Guard_IsNotNullOrEmpty_Ok));
+        }
+
+        [TestCategory("Guard")]
+        [TestMethod]
+        [ExpectedException(typeof(ArgumentNullException))]
+        public void Test_Guard_IsNotNullOrEmpty_Null()
+        {
+            Guard.IsNotNullOrEmpty(null, nameof(Test_Guard_IsNotNullOrEmpty_Null));
+        }
+
+        [TestCategory("Guard")]
+        [TestMethod]
+        [ExpectedException(typeof(ArgumentException))]
+        public void Test_Guard_IsNotNullOrEmpty_Empty()
+        {
+            Guard.IsNotNullOrEmpty(string.Empty, nameof(Test_Guard_IsNotNullOrEmpty_Empty));
+        }
+
+        [TestCategory("Guard")]
+        [TestMethod]
+        public void Test_Guard_IsNotNullOrWhiteSpace_Ok()
+        {
+            Guard.IsNotNullOrWhiteSpace("Hello", nameof(Test_Guard_IsNotNullOrWhiteSpace_Ok));
+        }
+
+        [TestCategory("Guard")]
+        [TestMethod]
+        [ExpectedException(typeof(ArgumentNullException))]
+        public void Test_Guard_IsNotNullOrWhiteSpace_Null()
+        {
+            Guard.IsNotNullOrWhiteSpace(null, nameof(Test_Guard_IsNotNullOrWhiteSpace_Null));
+        }
+
+        [TestCategory("Guard")]
+        [TestMethod]
+        [ExpectedException(typeof(ArgumentException))]
+        public void Test_Guard_IsNotNullOrWhiteSpace_Empty()
+        {
+            Guard.IsNotNullOrWhiteSpace("  ", nameof(Test_Guard_IsNotNullOrWhiteSpace_Empty));
+        }
+
         [TestCategory("Guard")]
         [TestMethod]
         public void Test_Guard_IsEqualTo_Ok()