Add AmbientValueAttribute tests and fix a debug assertion (#22027)

* Add AmbientValueAttribute tests and fix a debug assertion

* Address PR feedback

3 files changed, 172 insertions, 56 deletions

diff --git a/src/System.ComponentModel.TypeConverter/src/System/ComponentModel/AmbientValueAttribute.cs b/src/System.ComponentModel.TypeConverter/src/System/ComponentModel/AmbientValueAttribute.cs
index 4b26b4074b..f1be518264 100644
--- a/src/System.ComponentModel.TypeConverter/src/System/ComponentModel/AmbientValueAttribute.cs
+++ b/src/System.ComponentModel.TypeConverter/src/System/ComponentModel/AmbientValueAttribute.cs
@@ -2,33 +2,26 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System;
-using System.ComponentModel;
-using System.Diagnostics;
-using System.Globalization;
-using System.Runtime.InteropServices;
-using System.Security.Permissions;
+using System.Diagnostics.CodeAnalysis;
 
 namespace System.ComponentModel
 {
     /// <summary>
-    ///    <para>Specifies the ambient value for a property.  The ambient value is the value you
-    ///    can set into a property to make it inherit its ambient.</para>
+    /// Specifies the ambient value for a property. The ambient value is the value you
+    /// can set into a property to make it inherit its ambient.
     /// </summary>
-    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1019:DefineAccessorsForAttributeArguments")]
+    [SuppressMessage("Microsoft.Design", "CA1019:DefineAccessorsForAttributeArguments")]
     [AttributeUsage(AttributeTargets.All)]
     public sealed class AmbientValueAttribute : Attribute
     {
         /// <summary>
-        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.AmbientValueAttribute'/> class, converting the
-        ///    specified value to the
-        ///    specified type, and using the U.S. English culture as the
-        ///    translation
-        ///    context.</para>
+        /// Initializes a new instance of the <see cref='System.ComponentModel.AmbientValueAttribute'/> class, converting the
+        /// specified value to the specified type, and using the U.S. English culture as the
+        /// translation context.
         /// </summary>
         public AmbientValueAttribute(Type type, string value)
         {
-            // The try/catch here is because attributes should never throw exceptions.  We would fail to
+            // The try/catch here is because attributes should never throw exceptions. We would fail to
             // load an otherwise normal class.
             try
             {
@@ -36,42 +29,45 @@ namespace System.ComponentModel
             }
             catch
             {
-                Debug.Fail($"Ambient value attribute of type {type.FullName} threw converting from the string '{value}'.");
             }
         }
 
         /// <summary>
-        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.AmbientValueAttribute'/> class using a Unicode
-        ///    character.</para>
+        /// Initializes a new instance of the <see cref='System.ComponentModel.AmbientValueAttribute'/> class using a Unicode
+        /// character.
         /// </summary>
         public AmbientValueAttribute(char value)
         {
             Value = value;
         }
+
         /// <summary>
-        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.AmbientValueAttribute'/> class using an 8-bit unsigned
-        ///    integer.</para>
+        /// Initializes a new instance of the <see cref='System.ComponentModel.AmbientValueAttribute'/> class using an 8-bit unsigned
+        /// integer.
         /// </summary>
         public AmbientValueAttribute(byte value)
         {
             Value = value;
         }
+
         /// <summary>
-        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.AmbientValueAttribute'/> class using a 16-bit signed
-        ///    integer.</para>
+        /// Initializes a new instance of the <see cref='System.ComponentModel.AmbientValueAttribute'/> class using a 16-bit signed
+        /// integer.
         /// </summary>
         public AmbientValueAttribute(short value)
         {
             Value = value;
         }
+
         /// <summary>
-        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.AmbientValueAttribute'/> class using a 32-bit signed
-        ///    integer.</para>
+        /// Initializes a new instance of the <see cref='System.ComponentModel.AmbientValueAttribute'/> class using a 32-bit signed
+        /// integer.
         /// </summary>
         public AmbientValueAttribute(int value)
         {
             Value = value;
         }
+
         /// <summary>
         /// <para>Initializes a new instance of the <see cref='System.ComponentModel.AmbientValueAttribute'/> class using a 64-bit signed
         ///    integer.</para>
@@ -80,34 +76,36 @@ namespace System.ComponentModel
         {
             Value = value;
         }
+
         /// <summary>
-        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.AmbientValueAttribute'/> class using a
-        ///    single-precision floating point
-        ///    number.</para>
+        /// Initializes a new instance of the <see cref='System.ComponentModel.AmbientValueAttribute'/> class using a
+        /// single-precision floating point number.
         /// </summary>
         public AmbientValueAttribute(float value)
         {
             Value = value;
         }
+
         /// <summary>
-        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.AmbientValueAttribute'/> class using a
-        ///    double-precision floating point
-        ///    number.</para>
+        /// Initializes a new instance of the <see cref='System.ComponentModel.AmbientValueAttribute'/> class using a
+        /// double-precision floating point number.
         /// </summary>
         public AmbientValueAttribute(double value)
         {
             Value = value;
         }
+
         /// <summary>
-        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.AmbientValueAttribute'/> class using a <see cref='System.Boolean'/>
-        /// value.</para>
+        /// Initializes a new instance of the <see cref='System.ComponentModel.AmbientValueAttribute'/> class using a <see cref='System.Boolean'/>
+        /// value.
         /// </summary>
         public AmbientValueAttribute(bool value)
         {
             Value = value;
         }
+
         /// <summary>
-        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.AmbientValueAttribute'/> class using a <see cref='System.String'/>.</para>
+        /// Initializes a new instance of the <see cref='System.ComponentModel.AmbientValueAttribute'/> class using a <see cref='System.String'/>.
         /// </summary>
         public AmbientValueAttribute(string value)
         {
@@ -115,8 +113,8 @@ namespace System.ComponentModel
         }
 
         /// <summary>
-        /// <para>Initializes a new instance of the <see cref='System.ComponentModel.AmbientValueAttribute'/>
-        /// class.</para>
+        /// Initializes a new instance of the <see cref='System.ComponentModel.AmbientValueAttribute'/>
+        /// class.
         /// </summary>
         public AmbientValueAttribute(object value)
         {
@@ -124,11 +122,7 @@ namespace System.ComponentModel
         }
 
         /// <summary>
-        ///    <para>
-        ///       Gets the ambient value of the property this
-        ///       attribute is
-        ///       bound to.
-        ///    </para>
+        /// Gets the ambient value of the property this attribute is bound to.
         /// </summary>
         public object Value { get; }
 
@@ -139,26 +133,14 @@ namespace System.ComponentModel
                 return true;
             }
 
-            AmbientValueAttribute other = obj as AmbientValueAttribute;
-
-            if (other != null)
+            if (obj is AmbientValueAttribute other)
             {
-                if (Value != null)
-                {
-                    return Value.Equals(other.Value);
-                }
-                else
-                {
-                    return (other.Value == null);
-                }
+                return Value != null ? Value.Equals(other.Value) : other.Value == null;
             }
+
             return false;
         }
 
-        public override int GetHashCode()
-        {
-            return base.GetHashCode();
-        }
+        public override int GetHashCode() => base.GetHashCode();
     }
 }
-
diff --git a/src/System.ComponentModel.TypeConverter/tests/AmbientValueAttributeTests.cs b/src/System.ComponentModel.TypeConverter/tests/AmbientValueAttributeTests.cs
new file mode 100644
index 0000000000..166670a484
--- /dev/null
+++ b/src/System.ComponentModel.TypeConverter/tests/AmbientValueAttributeTests.cs
@@ -0,0 +1,133 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections.Generic;
+using Xunit;
+
+namespace System.ComponentModel.Tests
+{
+    public class AmbientValueAttributeTests
+    {
+        [Theory]
+        [InlineData(null, null, null)]
+        [InlineData(typeof(int*), "1", null)]
+        [InlineData(typeof(string), "1", "1")]
+        [InlineData(typeof(int), "1", 1)]
+        public void Ctor_Type_Value(Type type, string value, object expectedValue)
+        {
+            var attribute = new AmbientValueAttribute(type, value);
+            Assert.Equal(expectedValue, attribute.Value);
+        }
+
+        [Fact]
+        public void Ctor_Char()
+        {
+            char value = 'a';
+            var args = new AmbientValueAttribute(value);
+            Assert.Equal(value, args.Value);
+        }
+
+        [Fact]
+        public void Ctor_Byte()
+        {
+            byte value = 123;
+            var args = new AmbientValueAttribute(value);
+            Assert.Equal(value, args.Value);
+        }
+
+        [Fact]
+        public void Ctor_Short()
+        {
+            short value = 123;
+            var args = new AmbientValueAttribute(value);
+            Assert.Equal(value, args.Value);
+        }
+
+        [Fact]
+        public void Ctor_Int()
+        {
+            int value = 123;
+            var args = new AmbientValueAttribute(value);
+            Assert.Equal(value, args.Value);
+        }
+
+        [Fact]
+        public void Ctor_Long()
+        {
+            long value = 123;
+            var args = new AmbientValueAttribute(value);
+            Assert.Equal(value, args.Value);
+        }
+
+        [Fact]
+        public void Ctor_Float()
+        {
+            float value = 123;
+            var args = new AmbientValueAttribute(value);
+            Assert.Equal(value, args.Value);
+        }
+
+        [Fact]
+        public void Ctor_Double()
+        {
+            double value = 123;
+            var args = new AmbientValueAttribute(value);
+            Assert.Equal(value, args.Value);
+        }
+
+        [Fact]
+        public void Ctor_Bool()
+        {
+            bool value = true;
+            var args = new AmbientValueAttribute(value);
+            Assert.Equal(value, args.Value);
+        }
+
+        [Theory]
+        [InlineData(null)]
+        [InlineData("Value")]
+        public void Ctor_String(string value)
+        {
+            var args = new AmbientValueAttribute(value);
+            Assert.Same(value, args.Value);
+        }
+
+        [Theory]
+        [InlineData(null)]
+        [InlineData("Value")]
+        public void Ctor_Object(object value)
+        {
+            var args = new AmbientValueAttribute(value);
+            Assert.Same(value, args.Value);
+        }
+
+        public static IEnumerable<object[]> Equals_TestData()
+        {
+            var attribute = new AmbientValueAttribute(true);
+            yield return new object[] { attribute, attribute, true };
+            yield return new object[] { new AmbientValueAttribute(true), new AmbientValueAttribute(true), true };
+            yield return new object[] { new AmbientValueAttribute(true), new AmbientValueAttribute(false), false };
+            yield return new object[] { new AmbientValueAttribute(true), new AmbientValueAttribute(null), false };
+            yield return new object[] { new AmbientValueAttribute(null), new AmbientValueAttribute(false), false };
+            yield return new object[] { new AmbientValueAttribute(null), new AmbientValueAttribute(null), true };
+
+            yield return new object[] { new AmbientValueAttribute(true), new object(), false };
+            yield return new object[] { new AmbientValueAttribute(true), null, false };
+        }
+
+        [Theory]
+        [MemberData(nameof(Equals_TestData))]
+        public void Equals_Object_ReturnsExpected(AmbientValueAttribute attribute, object other, bool expected)
+        {
+            Assert.Equal(expected, attribute.Equals(other));
+        }
+
+        [Fact]
+        public void GetHashCode_Invoke_ReturnsConsistentValue()
+        {
+            var attribute = new AmbientValueAttribute(null);
+            Assert.Equal(attribute.GetHashCode(), attribute.GetHashCode());
+        }
+    }
+}
diff --git a/src/System.ComponentModel.TypeConverter/tests/System.ComponentModel.TypeConverter.Tests.csproj b/src/System.ComponentModel.TypeConverter/tests/System.ComponentModel.TypeConverter.Tests.csproj
index 7327afe6ec..23c5f5cdcd 100644
--- a/src/System.ComponentModel.TypeConverter/tests/System.ComponentModel.TypeConverter.Tests.csproj
+++ b/src/System.ComponentModel.TypeConverter/tests/System.ComponentModel.TypeConverter.Tests.csproj
@@ -25,6 +25,7 @@
     <Compile Include="$(CommonTestPath)\System\PlatformDetection.cs">
       <Link>Common\tests\System\PlatformDetection.cs</Link>
     </Compile>
+    <Compile Include="AmbientValueAttributeTests.cs" />
     <Compile Include="ArrayConverterTests.cs" />
     <Compile Include="AttributeCollectionTests.cs" />
     <Compile Include="AttributeProviderAttributeTests.cs" />