Fix errors when dotnet prerelease runtimes are installed

Author: CharliePoole

src/NUnitEngine/nunit.engine.core.tests/DotNetHelperTests.cs

@@ -61,8 +61,14 @@ public static void CanParseInputLine(string line, string name, string packageVer
                 true, new Version(9,0,0), "rc.2.24474.3")];
 
         [TestCase("Microsoft.NETCore.App", "8.0.0", "8.0.22")]
+        [TestCase("Microsoft.NETCore.App", "8.0.0.0", "8.0.22")]
+        [TestCase("Microsoft.NETCore.App", "8.0.0.100", "8.0.22")]
+        [TestCase("Microsoft.NETCore.App", "8.0.100", "9.0.11")]
+        [TestCase("Microsoft.AspNetCore.App", "5.0.0", "8.0.22")] // Rather than 8.0.2
+        [TestCase("Microsoft.AspNetCore.App", "7.0.0", "8.0.22")] // Rather than 8.0.2
         [TestCase("Microsoft.AspNetCore.App", "8.0.0", "8.0.22")] // Rather than 8.0.2
         [TestCase("Microsoft.WindowsDesktop.App", "9.0.0", "9.0.11")] // Rather than the pre-release version
+        [TestCase("Microsoft.WindowsDesktop.App", "10.0.0", "10.0.0-rc.2.25502.107")]
         public static void FindBestRuntimeTests(string runtimeName, string targetVersion, string expectedVersion)
         {
             var availableRuntimes = SimulatedListRuntimesOutput.Where(r => r.Name == runtimeName);
@@ -86,7 +92,7 @@ public static void FindBestRuntimeTests(string runtimeName, string targetVersion
             DotNet.RuntimeInfo.Parse(@"Microsoft.WindowsDesktop.App 8.0.22 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]"),
             DotNet.RuntimeInfo.Parse(@"Microsoft.WindowsDesktop.App 9.0.0-rc.2.24474.4 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]"),
             DotNet.RuntimeInfo.Parse(@"Microsoft.WindowsDesktop.App 9.0.11 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]"),
-            DotNet.RuntimeInfo.Parse(@"Microsoft.WindowsDesktop.App 10.0.0-rc.2.25502.107 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]"),
-            DotNet.RuntimeInfo.Parse(@"Microsoft.WindowsDesktop.App 10.0.0 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]") ];
+            DotNet.RuntimeInfo.Parse(@"Microsoft.WindowsDesktop.App 10.0.0-rc.2.25502.107 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]") ];
+            //DotNet.RuntimeInfo.Parse(@"Microsoft.WindowsDesktop.App 10.0.0 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]") ];
     }
 }

src/NUnitEngine/nunit.engine.core/DotNetHelper.cs

@@ -114,7 +114,7 @@ internal static bool FindBestRuntime(Version targetVersion, IEnumerable<RuntimeI
             foreach (var candidate in availableRuntimes)
             {
                 if (candidate.Version >= targetVersion)
-                    if (bestRuntime is null || candidate.Version.Major == targetVersion.Major)
+                    if (bestRuntime is null || candidate.Version.Major == bestRuntime.Version.Major)
                         bestRuntime = candidate;
             }