More correct image name normalization (#119)

more correct image name normalization

Author: baronfel

Microsoft.NET.Build.Containers/ContainerHelpers.cs

@@ -5,14 +5,14 @@ namespace Microsoft.NET.Build.Containers;
 
 public static class ContainerHelpers
 {
-    private static Regex imageTagRegex = new Regex("^[a-zA-Z0-9_][a-zA-Z0-9._-]{0,127}$");
+    private static Regex imageTagRegex = new Regex(@"^[a-zA-Z0-9_][a-zA-Z0-9._-]{0,127}$");
 
-    private static Regex imageNameRegex = new Regex("^[a-z0-9]+([._-][a-z0-9]+)*(/[a-z0-9]+([._-][a-z0-9]+)*)*$");
+    private static Regex imageNameRegex = new Regex(@"^[a-z0-9]+([._-][a-z0-9]+)*(/[a-z0-9]+([._-][a-z0-9]+)*)*$");
 
     /// <summary>
     /// Matches if the string is not lowercase or numeric, or ., _, or -.
     /// </summary>
-    private static Regex imageNameCharacters = new Regex("[^a-zA-Z0-9._-]");
+    private static Regex imageNameCharacters = new Regex(@"[^a-z0-9._\-/]");
 
     /// <summary>
     /// Given some "fully qualified" image name (e.g. mcr.microsoft.com/dotnet/runtime), return
@@ -133,13 +133,11 @@ public static bool NormalizeImageName(string containerImageName, [NotNullWhen(fa
         }
         else
         {
-            if (Char.IsUpper(containerImageName, 0))
-            {
-                containerImageName = Char.ToLowerInvariant(containerImageName[0]) + containerImageName[1..];
-            } else if (!Char.IsLetterOrDigit(containerImageName, 0)) {
+            if (!Char.IsLetterOrDigit(containerImageName, 0)) {
                 throw new ArgumentException("The first character of the image name must be a lowercase letter or a digit.");
             }
-            normalizedImageName = imageNameCharacters.Replace(containerImageName, "-");
+            var loweredImageName = containerImageName.ToLowerInvariant();
+            normalizedImageName = imageNameCharacters.Replace(loweredImageName, "-");
             return false;
         }
     }

Test.Microsoft.NET.Build.Containers.Filesystem/TargetsTests.cs

@@ -83,10 +83,11 @@ public void CanSetEntrypointArgsToUseAppHost(bool useAppHost, params string[] en
         }
     }
 
-    [DataRow("WebApplication44", "webApplication44", true)]
+    [DataRow("WebApplication44", "webapplication44", true)]
     [DataRow("friendly-suspicious-alligator", "friendly-suspicious-alligator", true)]
     [DataRow("*friendly-suspicious-alligator", "", false)]
-    [DataRow("web/app2+7", "web-app2-7", true)]
+    [DataRow("web/app2+7", "web/app2-7", true)]
+    [DataRow("Microsoft.Apps.Demo.ContosoWeb", "microsoft.apps.demo.contosoweb", true)]
     [TestMethod]
     public void CanNormalizeInputContainerNames(string projectName, string expectedContainerImageName, bool shouldPass)
     {