add enum polyfill (#127)

src/Directory.Build.props

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project>
   <PropertyGroup>
-    <Version>2.1.0</Version>
+    <Version>2.2.0</Version>
     <AssemblyVersion>1.0.0</AssemblyVersion>
     <PackageTags>Polyfill</PackageTags>
     <DisableImplicitNamespaceImports>true</DisableImplicitNamespaceImports>

src/Polyfill/EnumPolyfill.cs

@@ -0,0 +1,46 @@
+// <auto-generated />
+
+#pragma warning disable
+
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using Link = System.ComponentModel.DescriptionAttribute;
+
+#if PolyPublic
+public
+#endif
+static partial class EnumPolyfill
+{
+    /// <summary>
+    /// Retrieves an array of the values of the constants in a specified enumeration type.
+    /// </summary>
+    /// <returns>An array that contains the values of the constants in TEnum.</returns>
+    [Link("https://learn.microsoft.com/en-us/dotnet/api/system.enum.getvalues")]
+    public static TEnum[] GetValues<TEnum>()
+        where TEnum : struct, Enum
+    {
+#if NETCOREAPPX || NETFRAMEWORK || NETSTANDARD
+       var values = Enum.GetValues(typeof(TEnum));
+       var result = new TEnum[values.Length];
+       Array.Copy(values, result, values.Length);
+       return result;
+#else
+       return Enum.GetValues<TEnum>();
+#endif
+    }
+    /// <summary>
+    /// Retrieves an array of the names of the constants in a specified enumeration type.
+    /// </summary>
+    /// <returns>A string array of the names of the constants in TEnum.</returns>
+    [Link("https://learn.microsoft.com/en-us/dotnet/api/system.enum.getnames")]
+    public static string[] GetNames<TEnum>()
+        where TEnum : struct, Enum
+    {
+#if NETCOREAPPX || NETFRAMEWORK || NETSTANDARD
+       return Enum.GetNames(typeof(TEnum));
+#else
+       return Enum.GetNames<TEnum>();
+#endif
+    }
+}

src/Tests/PolyfillTests_Enum.cs

@@ -0,0 +1,16 @@
+partial class PolyfillTests
+{
+    [Test]
+    public void EnumGetValues()
+    {
+        var dayOfWeeks = EnumPolyfill.GetValues<DayOfWeek>();
+        Assert.AreEqual(DayOfWeek.Sunday, dayOfWeeks[0]);
+    }
+
+    [Test]
+    public void EnumGetNames()
+    {
+        var dayOfWeeks = EnumPolyfill.GetNames<DayOfWeek>();
+        Assert.AreEqual("Sunday", dayOfWeeks[0]);
+    }
+}