Add NLS test scenario

tests/Microsoft.DotNet.Docker.Tests/AspnetImageTests.cs

@@ -35,6 +35,11 @@ public async Task VerifyFxDependentAppScenario(ProductImageData imageData)
         public async Task VerifyGlobalizationScenario(ProductImageData imageData) =>
             await VerifyGlobalizationScenarioBase(imageData);
 
+        [WindowsImageTheory]
+        [MemberData(nameof(GetImageData))]
+        public async Task VerifyNLSScenario(ProductImageData imageData) =>
+            await VerifyNlsScenarioBase(imageData);
+
         [DotNetTheory]
         [MemberData(nameof(GetImageData))]
         public void VerifyEnvironmentVariables(ProductImageData imageData)

tests/Microsoft.DotNet.Docker.Tests/CommonRuntimeImageTests.cs

@@ -82,5 +82,11 @@ protected async Task VerifyGlobalizationScenarioBase(ProductImageData imageData)
             using var testScenario = new GlobalizationScenario(imageData, ImageRepo, DockerHelper);
             await testScenario.ExecuteAsync();
         }
+
+        protected async Task VerifyNlsScenarioBase(ProductImageData imageData)
+        {
+            using var testScenario = new NlsScenario(imageData, ImageRepo, DockerHelper);
+            await testScenario.ExecuteAsync();
+        }
     }
 }

tests/Microsoft.DotNet.Docker.Tests/Microsoft.DotNet.Docker.Tests.csproj

@@ -26,8 +26,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <Compile Remove="TestAppArtifacts\GlobalizationTest.cs" />
-    <Compile Remove="TestAppArtifacts\UnitTests.cs" />
+    <Compile Remove="TestAppArtifacts/*.cs" />
   </ItemGroup>
 
 </Project>

tests/Microsoft.DotNet.Docker.Tests/RuntimeImageTests.cs

@@ -47,6 +47,11 @@ public async Task VerifyTestProjectScenario(ProductImageData imageData)
         public async Task VerifyGlobalizationScenario(ProductImageData imageData) =>
             await VerifyGlobalizationScenarioBase(imageData);
 
+        [WindowsImageTheory]
+        [MemberData(nameof(GetImageData))]
+        public async Task VerifyNLSScenario(ProductImageData imageData) =>
+            await VerifyNlsScenarioBase(imageData);
+
         [DotNetTheory]
         [MemberData(nameof(GetImageData))]
         public void VerifyEnvironmentVariables(ProductImageData imageData)

tests/Microsoft.DotNet.Docker.Tests/TestAppArtifacts/NLSTest.Dockerfile

@@ -0,0 +1,15 @@
+ARG sdk_image
+ARG runtime_image
+
+FROM ${sdk_image} AS sdk
+RUN dotnet new console -n App -o /src --no-restore
+WORKDIR /src
+COPY NLSTest.cs /src/Program.cs
+RUN dotnet restore
+RUN dotnet publish --no-restore -o /app
+
+FROM ${runtime_image} AS runtime
+ARG icu_expected
+ENV ICU_EXPECTED=${icu_expected}
+COPY --from=sdk /app /app/
+ENTRYPOINT ["/app/App"]

tests/Microsoft.DotNet.Docker.Tests/TestAppArtifacts/NLSTest.cs

@@ -0,0 +1,87 @@
+using System.Globalization;
+using static System.Console;
+
+const string nlsVar = "DOTNET_SYSTEM_GLOBALIZATION_USENLS";
+const string icuVar = "ICU_EXPECTED";
+
+GetEnvironmentVariableValue(nlsVar);
+bool icuExpected = GetEnvironmentVariableValue(icuVar);
+
+bool icuMode = IsIcuMode();
+WriteLine($"Detected ICU mode: {icuMode}");
+
+if (icuMode != icuExpected)
+{
+    throw new Exception($"ICU mode detected as {icuMode}, expected {icuExpected}");
+}
+
+// https://learn.microsoft.com/en-us/dotnet/core/extensions/globalization-icu#stringendswith
+Assert(
+    """ "abc".EndsWith("\0")""",
+    "abc".EndsWith("\0").ToString(),
+    icuResult: true.ToString(),
+    nlsResult: false.ToString(),
+    icuMode);
+Assert(
+    """ "abc".EndsWith("\0", StringComparison.CurrentCulture)""",
+    "abc".EndsWith("\0", StringComparison.CurrentCulture).ToString(),
+    icuResult: true.ToString(),
+    nlsResult: false.ToString(),
+    icuMode);
+
+// https://learn.microsoft.com/en-us/dotnet/core/extensions/globalization-icu#stringstartswith
+Assert(
+    """ "foo".StartsWith("\0")""",
+    "foo".StartsWith("\0").ToString(),
+    icuResult: true.ToString(),
+    nlsResult: false.ToString(),
+    icuMode);
+Assert(
+    """ "foo".StartsWith("\0", StringComparison.CurrentCulture)""",
+    "foo".StartsWith("\0", StringComparison.CurrentCulture).ToString(),
+    icuResult: true.ToString(),
+    nlsResult: false.ToString(),
+    icuMode);
+
+// https://learn.microsoft.com/en-us/dotnet/core/extensions/globalization-icu#stringindexof
+Assert(
+    """ "Hel\0lo".IndexOf("\0")""",
+    "Hel\0lo".IndexOf("\0").ToString(),
+    icuResult: "0",
+    nlsResult: "3",
+    icuMode);
+Assert(
+    """ "Hel\0lo".IndexOf("\0", StringComparison.CurrentCulture)""",
+    "Hel\0lo".IndexOf("\0", StringComparison.CurrentCulture).ToString(),
+    icuResult: "0",
+    nlsResult: "3",
+    icuMode);
+
+WriteLine("All assertions passed!");
+
+// https://learn.microsoft.com/en-us/dotnet/core/extensions/globalization-icu#determine-if-your-app-is-using-icu
+bool IsIcuMode()
+{
+    SortVersion sortVersion = CultureInfo.InvariantCulture.CompareInfo.Version;
+    byte[] bytes = sortVersion.SortId.ToByteArray();
+    int version = bytes[3] << 24 | bytes[2] << 16 | bytes[1] << 8 | bytes[0];
+    return version != 0 && version == sortVersion.FullVersion;
+}
+
+void Assert(string functionText, string actualResult, string icuResult, string nlsResult, bool icuExpected)
+{
+    string expectedResult = icuExpected ? icuResult : nlsResult;
+    Console.WriteLine($"{functionText} returned {actualResult}");
+    if (actualResult != expectedResult)
+    {
+        throw new Exception($"Assertion failed: {functionText} returned {actualResult}, expected {expectedResult}");
+    }
+}
+
+bool GetEnvironmentVariableValue(string variable)
+{
+    string value = Environment.GetEnvironmentVariable(variable);
+    bool parsedValue = !string.IsNullOrWhiteSpace(value) && bool.Parse(value);
+    WriteLine($"{variable} evaluated to {parsedValue}");
+    return parsedValue;
+}

tests/Microsoft.DotNet.Docker.Tests/TestScenarios/NlsScenario.cs

@@ -0,0 +1,83 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.IO;
+using System.Threading.Tasks;
+using FluentAssertions;
+
+namespace Microsoft.DotNet.Docker.Tests.TestScenarios;
+
+#nullable enable
+public sealed class NlsScenario : ITestScenario, IDisposable
+{
+    private const string DockerfileName = "NLSTest.Dockerfile";
+
+    private const string TestSourceFileName = "NLSTest.cs";
+
+    private readonly TempFolderContext _tempFolderContext = FileHelper.UseTempFolder();
+
+    private readonly ProductImageData _imageData;
+
+    private readonly DotNetImageRepo _repo;
+
+    private readonly DockerHelper _dockerHelper;
+
+    public NlsScenario(
+        ProductImageData imageData,
+        DotNetImageRepo repo,
+        DockerHelper dockerHelper)
+    {
+        _imageData = imageData;
+        _repo = repo;
+        _dockerHelper = dockerHelper;
+    }
+
+    // ICU is not supported on Nano Server
+    private bool IsIcuSupported => _imageData.OS.Contains(OS.ServerCore);
+
+    public Task ExecuteAsync()
+    {
+        // Setup project in temp dir
+        string dockerfilePath = Path.Combine(_tempFolderContext.Path, "Dockerfile");
+        File.Copy(
+            sourceFileName: Path.Combine(DockerHelper.TestArtifactsDir, DockerfileName),
+            destFileName: dockerfilePath);
+        File.Copy(
+            sourceFileName: Path.Combine(DockerHelper.TestArtifactsDir, TestSourceFileName),
+            destFileName: Path.Combine(_tempFolderContext.Path, TestSourceFileName));
+
+        string sdkImage = _imageData.GetImage(DotNetImageRepo.SDK, _dockerHelper);
+        string runtimeImage = _imageData.GetImage(_repo, _dockerHelper);
+        string[] buildArgs =
+        [
+            $"sdk_image={sdkImage}",
+            $"runtime_image={runtimeImage}",
+        ];
+
+        if (IsIcuSupported)
+        {
+            buildArgs = [..buildArgs, $"icu_expected={IsIcuSupported}"];
+        }
+
+        string tag = nameof(NlsScenario).ToLowerInvariant();
+        _dockerHelper.Build(
+            tag: tag,
+            dockerfile: dockerfilePath,
+            contextDir: _tempFolderContext.Path,
+            pull: Config.PullImages,
+            buildArgs: buildArgs);
+
+        string containerName = ImageData.GenerateContainerName(nameof(NlsScenario));
+        Func<string> runImage = () => _dockerHelper.Run(tag, containerName);
+
+        string justification = $"image {runtimeImage} should{(IsIcuSupported ? "" : " not")} support ICU";
+        runImage.Should().NotThrow(because: justification)
+            .Which.Should().ContainEquivalentOf("All assertions passed", Exactly.Once());
+
+        return Task.CompletedTask;
+    }
+
+    public void Dispose() => _tempFolderContext.Dispose();
+}

tests/Microsoft.DotNet.Docker.Tests/WindowsImageTheoryAttribute.cs

@@ -0,0 +1,16 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.DotNet.Docker.Tests;
+
+public class WindowsImageTheoryAttribute : DotNetTheoryAttribute
+{
+    public WindowsImageTheoryAttribute()
+    {
+        if (DockerHelper.IsLinuxContainerModeEnabled)
+        {
+            Skip = "Windows image test not applicable when running in Linux Container mode";
+        }
+    }
+}