Display net5.0 using ToString instead of custom logic (#8291)

Address #8235
Address #8268

Author: joelverhagen

src/NuGetGallery/ExtensionMethods.cs

@@ -243,6 +243,15 @@ public static string ToFriendlyName(this NuGetFramework frameworkName, bool allo
                 throw new ArgumentNullException(nameof(frameworkName));
             }
 
+            // Defer to the NuGet client logic for displaying .NET 5 frameworks. This aligns with Visual Studio package
+            // management UI.
+            var isNet5Era = frameworkName.Version.Major >= 5
+                && StringComparer.OrdinalIgnoreCase.Equals(FrameworkConstants.FrameworkIdentifiers.NetCoreApp, frameworkName.Framework);
+            if (isNet5Era)
+            {
+                return frameworkName.ToString();
+            }
+
             var sb = new StringBuilder();
             if (String.Equals(frameworkName.Framework, ".NETPortable", StringComparison.OrdinalIgnoreCase))
             {

tests/NuGetGallery.Facts/ExtensionMethodsFacts.cs

@@ -14,6 +14,19 @@ public class ExtensionMethodsFacts
         public class TheToFriendlyNameMethod
         {
             [Theory]
+            [InlineData("net5.0", "net5.0")]
+            [InlineData("net5.0", "NET5.0")]
+            [InlineData("net5.0", "net5")]
+            [InlineData("net5.0", "net50")]
+            [InlineData("net5.0", "netcoreapp5.0")]
+            [InlineData("net5.0", "netcoreapp50")]
+            [InlineData("net5.0-windows", "net5.0-windows")]
+            [InlineData("net5.0-windows9.0", "net5.0-windows9")]
+            [InlineData("net5.0-ios14.0", "net5.0-ios14.0")]
+            [InlineData("net5.0", "netcoreapp5.0-windows")] // See: https://github.com/NuGet/Home/issues/10177
+            [InlineData("net5.0", "netcoreapp5.0-windows9")] // See: https://github.com/NuGet/Home/issues/10177
+            [InlineData("net6.0", "net6.0")]
+            [InlineData("net10.0", "net10.0")]
             [InlineData(".NETFramework 4.0", "net40")]
             [InlineData("Silverlight 4.0", "sl40")]
             [InlineData("WindowsPhone 8.0", "wp8")]