fix(cluster-infrastructure): resolve ClusterInfrastructure-002..006 — options validation, DI registration, down-if-alone

tests/ScadaLink.ClusterInfrastructure.Tests/ClusterOptionsTests.cs

@@ -15,6 +15,15 @@ public class ClusterOptionsTests
         Assert.Equal(TimeSpan.FromSeconds(2), options.HeartbeatInterval);
         Assert.Equal(TimeSpan.FromSeconds(10), options.FailureDetectionThreshold);
         Assert.Equal(1, options.MinNrOfMembers);
+        Assert.True(options.DownIfAlone);
+    }
+
+    [Fact]
+    public void DownIfAlone_CanBeSet()
+    {
+        var options = new ClusterOptions { DownIfAlone = false };
+
+        Assert.False(options.DownIfAlone);
     }
 
     [Fact]

tests/ScadaLink.ClusterInfrastructure.Tests/ClusterOptionsValidatorTests.cs

@@ -0,0 +1,119 @@
+using Microsoft.Extensions.Options;
+
+namespace ScadaLink.ClusterInfrastructure.Tests;
+
+/// <summary>
+/// CI-004: Tests that <see cref="ClusterOptionsValidator"/> rejects the
+/// catastrophic misconfigurations the design doc warns against — a
+/// <c>MinNrOfMembers</c> other than 1, an unsupported split-brain strategy,
+/// empty seed nodes, and timings where the heartbeat is not below the
+/// failure-detection threshold.
+/// </summary>
+public class ClusterOptionsValidatorTests
+{
+    private static ClusterOptions ValidOptions() => new()
+    {
+        SeedNodes = new List<string> { "akka.tcp://scadalink@node1:8081", "akka.tcp://scadalink@node2:8081" },
+        SplitBrainResolverStrategy = "keep-oldest",
+        StableAfter = TimeSpan.FromSeconds(15),
+        HeartbeatInterval = TimeSpan.FromSeconds(2),
+        FailureDetectionThreshold = TimeSpan.FromSeconds(10),
+        MinNrOfMembers = 1,
+        DownIfAlone = true
+    };
+
+    [Fact]
+    public void DefaultOptions_AreValid()
+    {
+        var result = new ClusterOptionsValidator().Validate(null, ValidOptions());
+
+        Assert.True(result.Succeeded, result.FailureMessage);
+    }
+
+    [Fact]
+    public void MinNrOfMembers_NotOne_FailsValidation()
+    {
+        var options = ValidOptions();
+        options.MinNrOfMembers = 2;
+
+        var result = new ClusterOptionsValidator().Validate(null, options);
+
+        Assert.True(result.Failed);
+        Assert.Contains("MinNrOfMembers", result.FailureMessage);
+    }
+
+    [Theory]
+    [InlineData("keep-majority")]
+    [InlineData("static-quorum")]
+    [InlineData("nonsense")]
+    public void UnsupportedSplitBrainStrategy_FailsValidation(string strategy)
+    {
+        var options = ValidOptions();
+        options.SplitBrainResolverStrategy = strategy;
+
+        var result = new ClusterOptionsValidator().Validate(null, options);
+
+        Assert.True(result.Failed);
+        Assert.Contains("SplitBrainResolverStrategy", result.FailureMessage);
+    }
+
+    [Fact]
+    public void EmptySeedNodes_FailsValidation()
+    {
+        var options = ValidOptions();
+        options.SeedNodes = new List<string>();
+
+        var result = new ClusterOptionsValidator().Validate(null, options);
+
+        Assert.True(result.Failed);
+        Assert.Contains("SeedNodes", result.FailureMessage);
+    }
+
+    [Fact]
+    public void HeartbeatNotBelowFailureThreshold_FailsValidation()
+    {
+        var options = ValidOptions();
+        options.HeartbeatInterval = TimeSpan.FromSeconds(10);
+        options.FailureDetectionThreshold = TimeSpan.FromSeconds(10);
+
+        var result = new ClusterOptionsValidator().Validate(null, options);
+
+        Assert.True(result.Failed);
+        Assert.Contains("HeartbeatInterval", result.FailureMessage);
+    }
+
+    [Fact]
+    public void NonPositiveStableAfter_FailsValidation()
+    {
+        var options = ValidOptions();
+        options.StableAfter = TimeSpan.Zero;
+
+        var result = new ClusterOptionsValidator().Validate(null, options);
+
+        Assert.True(result.Failed);
+        Assert.Contains("StableAfter", result.FailureMessage);
+    }
+
+    [Fact]
+    public void Validate_AccumulatesAllFailures()
+    {
+        var options = new ClusterOptions
+        {
+            SeedNodes = new List<string>(),
+            SplitBrainResolverStrategy = "keep-majority",
+            MinNrOfMembers = 2,
+            StableAfter = TimeSpan.Zero,
+            HeartbeatInterval = TimeSpan.FromSeconds(20),
+            FailureDetectionThreshold = TimeSpan.FromSeconds(10)
+        };
+
+        var result = new ClusterOptionsValidator().Validate(null, options);
+
+        Assert.True(result.Failed);
+        Assert.Contains("SeedNodes", result.FailureMessage);
+        Assert.Contains("SplitBrainResolverStrategy", result.FailureMessage);
+        Assert.Contains("MinNrOfMembers", result.FailureMessage);
+        Assert.Contains("StableAfter", result.FailureMessage);
+        Assert.Contains("HeartbeatInterval", result.FailureMessage);
+    }
+}

tests/ScadaLink.ClusterInfrastructure.Tests/ScadaLink.ClusterInfrastructure.Tests.csproj

@@ -10,6 +10,8 @@
 
   <ItemGroup>
     <PackageReference Include="coverlet.collector" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" />
+    <PackageReference Include="Microsoft.Extensions.Options" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" />
     <PackageReference Include="xunit" />
     <PackageReference Include="xunit.runner.visualstudio" />

tests/ScadaLink.ClusterInfrastructure.Tests/ServiceCollectionExtensionsTests.cs

@@ -0,0 +1,58 @@
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Options;
+
+namespace ScadaLink.ClusterInfrastructure.Tests;
+
+/// <summary>
+/// CI-002: Tests that the DI extension methods do real work rather than
+/// silently returning success. <see cref="ServiceCollectionExtensions.AddClusterInfrastructure"/>
+/// must register the <see cref="ClusterOptionsValidator"/> so misconfiguration
+/// fails fast, and the unimplemented actor-registration placeholder must fail
+/// loudly rather than masquerade as a completed registration.
+/// </summary>
+public class ServiceCollectionExtensionsTests
+{
+    [Fact]
+    public void AddClusterInfrastructure_RegistersOptionsValidator()
+    {
+        var services = new ServiceCollection();
+
+        services.AddClusterInfrastructure();
+
+        var validators = services
+            .Where(d => d.ServiceType == typeof(IValidateOptions<ClusterOptions>))
+            .ToList();
+        Assert.NotEmpty(validators);
+
+        using var provider = services.BuildServiceProvider();
+        var validator = provider.GetService<IValidateOptions<ClusterOptions>>();
+        Assert.IsType<ClusterOptionsValidator>(validator);
+    }
+
+    [Fact]
+    public void AddClusterInfrastructure_ValidatorRejectsBadOptionsAtResolution()
+    {
+        var services = new ServiceCollection();
+        services.AddClusterInfrastructure();
+        // A MinNrOfMembers of 2 blocks the cluster singleton after failover.
+        services.Configure<ClusterOptions>(o =>
+        {
+            o.SeedNodes = new List<string> { "akka.tcp://scadalink@node1:8081" };
+            o.MinNrOfMembers = 2;
+        });
+
+        using var provider = services.BuildServiceProvider();
+
+        var ex = Assert.Throws<OptionsValidationException>(
+            () => provider.GetRequiredService<IOptions<ClusterOptions>>().Value);
+        Assert.Contains("MinNrOfMembers", ex.Message);
+    }
+
+    [Fact]
+    public void AddClusterInfrastructureActors_ThrowsRatherThanSilentlySucceeding()
+    {
+        var services = new ServiceCollection();
+
+        Assert.Throws<NotImplementedException>(() => services.AddClusterInfrastructureActors());
+    }
+}