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

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);
+    }
+}