From e7bdb20b19cd4d6b922c9c96cca8436d68d92c8f Mon Sep 17 00:00:00 2001
From: Oliver Booth <me@olivr.me>
Date: Fri, 29 Apr 2022 11:17:02 +0100
Subject: [PATCH] Add tests for reflection extensions

---
 X10D.Tests/src/Reflection/MemberInfoTests.cs | 78 ++++++++++++++++++++
 X10D.Tests/src/Reflection/TypeTests.cs       | 59 +++++++++++++++
 2 files changed, 137 insertions(+)
 create mode 100644 X10D.Tests/src/Reflection/MemberInfoTests.cs
 create mode 100644 X10D.Tests/src/Reflection/TypeTests.cs

diff --git a/X10D.Tests/src/Reflection/MemberInfoTests.cs b/X10D.Tests/src/Reflection/MemberInfoTests.cs
new file mode 100644
index 0000000..24d2675
--- /dev/null
+++ b/X10D.Tests/src/Reflection/MemberInfoTests.cs
@@ -0,0 +1,78 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using X10D.Reflection;
+
+namespace X10D.Tests.Reflection;
+
+[TestClass]
+public class MemberInfoTests
+{
+    [TestMethod]
+    public void HasCustomAttribute_ShouldBeTrue_GivenCLSCompliantAttributeOnUnsignedTypes()
+    {
+        Assert.IsTrue(typeof(sbyte).HasCustomAttribute(typeof(CLSCompliantAttribute))); // okay, sbyte is signed. I know.
+        Assert.IsTrue(typeof(ushort).HasCustomAttribute(typeof(CLSCompliantAttribute)));
+        Assert.IsTrue(typeof(uint).HasCustomAttribute(typeof(CLSCompliantAttribute)));
+        Assert.IsTrue(typeof(ulong).HasCustomAttribute(typeof(CLSCompliantAttribute)));
+    }
+
+    [TestMethod]
+    public void HasCustomAttribute_ShouldBeTrue_GivenCLSCompliantAttributeOnUnsignedTypes_Generic()
+    {
+        Assert.IsTrue(typeof(sbyte).HasCustomAttribute<CLSCompliantAttribute>()); // okay, sbyte is signed. I know.
+        Assert.IsTrue(typeof(ushort).HasCustomAttribute<CLSCompliantAttribute>());
+        Assert.IsTrue(typeof(uint).HasCustomAttribute<CLSCompliantAttribute>());
+        Assert.IsTrue(typeof(ulong).HasCustomAttribute<CLSCompliantAttribute>());
+    }
+
+    [TestMethod]
+    public void HasCustomAttribute_ShouldThrow_GivenNull()
+    {
+        Type? type = null;
+        Assert.ThrowsException<ArgumentNullException>(() => type!.HasCustomAttribute<CLSCompliantAttribute>());
+        Assert.ThrowsException<ArgumentNullException>(() => type!.HasCustomAttribute(typeof(CLSCompliantAttribute)));
+
+        Assert.ThrowsException<ArgumentNullException>(() => typeof(object).HasCustomAttribute(null!));
+    }
+
+    [TestMethod]
+    public void HasCustomAttribute_ShouldThrow_GivenNonAttribute()
+    {
+        Assert.ThrowsException<ArgumentException>(() => typeof(object).HasCustomAttribute(typeof(object)));
+    }
+
+    [TestMethod]
+    public void SelectFromCustomAttribute_ShouldBeFalse_GivenCLSCompliantAttributeOnUnsignedTypes()
+    {
+        Assert.IsFalse(typeof(sbyte).SelectFromCustomAttribute((CLSCompliantAttribute attribute) => attribute.IsCompliant));
+        Assert.IsFalse(typeof(ushort).SelectFromCustomAttribute((CLSCompliantAttribute attribute) => attribute.IsCompliant));
+        Assert.IsFalse(typeof(uint).SelectFromCustomAttribute((CLSCompliantAttribute attribute) => attribute.IsCompliant));
+        Assert.IsFalse(typeof(ulong).SelectFromCustomAttribute((CLSCompliantAttribute attribute) => attribute.IsCompliant));
+    }
+
+    [TestMethod]
+    public void SelectFromCustomAttribute_ShouldBeTrue_GivenCLSCompliantAttributeOnSignedTypes()
+    {
+        Assert.IsTrue(typeof(byte).SelectFromCustomAttribute((CLSCompliantAttribute attribute) => attribute.IsCompliant, true));
+        Assert.IsTrue(typeof(short).SelectFromCustomAttribute((CLSCompliantAttribute attribute) => attribute.IsCompliant, true));
+        Assert.IsTrue(typeof(int).SelectFromCustomAttribute((CLSCompliantAttribute attribute) => attribute.IsCompliant, true));
+        Assert.IsTrue(typeof(long).SelectFromCustomAttribute((CLSCompliantAttribute attribute) => attribute.IsCompliant, true));
+    }
+
+    [TestMethod]
+    public void SelectFromCustomAttribute_ShouldThrow_GivenNull()
+    {
+        Type? type = null;
+
+        Assert.ThrowsException<ArgumentNullException>(() =>
+            (type!.SelectFromCustomAttribute((CLSCompliantAttribute attribute) => attribute.IsCompliant)));
+
+        Assert.ThrowsException<ArgumentNullException>(() =>
+            (type!.SelectFromCustomAttribute((CLSCompliantAttribute attribute) => attribute.IsCompliant, true)));
+
+        Assert.ThrowsException<ArgumentNullException>(() =>
+        {
+            Func<CLSCompliantAttribute, bool>? selector = null;
+            typeof(int).SelectFromCustomAttribute(selector!);
+        });
+    }
+}
diff --git a/X10D.Tests/src/Reflection/TypeTests.cs b/X10D.Tests/src/Reflection/TypeTests.cs
new file mode 100644
index 0000000..4324afb
--- /dev/null
+++ b/X10D.Tests/src/Reflection/TypeTests.cs
@@ -0,0 +1,59 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using X10D.Reflection;
+
+namespace X10D.Tests.Reflection;
+
+[TestClass]
+public class TypeTests
+{
+    [TestMethod]
+    public void Inherits_ShouldBeTrue_GivenStringInheritsObject()
+    {
+        Assert.IsTrue(typeof(string).Inherits(typeof(object)));
+        Assert.IsTrue(typeof(string).Inherits<object>());
+    }
+
+    [TestMethod]
+    public void Inherits_ShouldBeFalse_GivenObjectInheritsString()
+    {
+        Assert.IsFalse(typeof(object).Inherits(typeof(string)));
+        Assert.IsFalse(typeof(object).Inherits<string>());
+    }
+
+    [TestMethod]
+    public void Inherits_ShouldThrow_GivenValueType()
+    {
+        Assert.ThrowsException<ArgumentException>(() => typeof(int).Inherits(typeof(object)));
+        Assert.ThrowsException<ArgumentException>(() => typeof(object).Inherits(typeof(int)));
+    }
+
+    [TestMethod]
+    public void Inherits_ShouldThrow_GivenNull()
+    {
+        Assert.ThrowsException<ArgumentNullException>(() => typeof(object).Inherits(null!));
+        Assert.ThrowsException<ArgumentNullException>(() => ((Type?)null)!.Inherits(typeof(object)));
+    }
+
+    [TestMethod]
+    public void Implements_ShouldBeTrue_GivenInt32ImplementsIComparable()
+    {
+        Assert.IsTrue(typeof(int).Implements<IComparable>());
+        Assert.IsTrue(typeof(int).Implements<IComparable<int>>());
+        Assert.IsTrue(typeof(int).Implements(typeof(IComparable)));
+        Assert.IsTrue(typeof(int).Implements(typeof(IComparable<int>)));
+    }
+
+    [TestMethod]
+    public void Implements_ShouldThrow_GivenNull()
+    {
+        Assert.ThrowsException<ArgumentNullException>(() => typeof(object).Implements(null!));
+        Assert.ThrowsException<ArgumentNullException>(() => ((Type?)null)!.Implements(typeof(object)));
+    }
+
+    [TestMethod]
+    public void Implements_ShouldThrow_GivenNonInterface()
+    {
+        Assert.ThrowsException<ArgumentException>(() => typeof(string).Implements<object>());
+        Assert.ThrowsException<ArgumentException>(() => typeof(string).Implements(typeof(object)));
+    }
+}