stabilizaiton work - projects rework for maintenanceability and ui livening

src/__Libraries/__Tests/StellaOps.TestKit.Tests/EvidenceChainTests.Artifacts.cs

@@ -0,0 +1,74 @@
+using System;
+using FluentAssertions;
+using StellaOps.TestKit.Evidence;
+using Xunit;
+
+namespace StellaOps.TestKit.Tests;
+
+public sealed partial class EvidenceChainTests
+{
+    [Fact]
+    public void ArtifactHashStable_PassesWithCorrectHash()
+    {
+        var content = "test artifact";
+        var expectedHash = EvidenceChainAssert.ComputeSha256(content);
+
+        var act = () => EvidenceChainAssert.ArtifactHashStable(content, expectedHash);
+        act.Should().NotThrow();
+    }
+
+    [Fact]
+    public void ArtifactHashStable_ThrowsWithIncorrectHash()
+    {
+        var content = "test artifact";
+        var wrongHash = new string('0', 64);
+
+        var act = () => EvidenceChainAssert.ArtifactHashStable(content, wrongHash);
+        act.Should().Throw<EvidenceTraceabilityException>()
+            .WithMessage("*Artifact hash mismatch*");
+    }
+
+    [Fact]
+    public void ArtifactHashStable_ThrowsOnNullArtifact()
+    {
+        var act = () => EvidenceChainAssert.ArtifactHashStable((byte[])null!, "hash");
+        act.Should().Throw<ArgumentNullException>();
+    }
+
+    [Fact]
+    public void ArtifactImmutable_PassesWithDeterministicGenerator()
+    {
+        var counter = 0;
+        Func<string> generator = () =>
+        {
+            counter++;
+            return "immutable content";
+        };
+
+        var act = () => EvidenceChainAssert.ArtifactImmutable(generator, iterations: 5);
+        act.Should().NotThrow();
+        counter.Should().Be(5);
+    }
+
+    [Fact]
+    public void ArtifactImmutable_ThrowsWithNonDeterministicGenerator()
+    {
+        var counter = 0;
+        Func<string> generator = () =>
+        {
+            counter++;
+            return $"non-deterministic content {counter}";
+        };
+
+        var act = () => EvidenceChainAssert.ArtifactImmutable(generator, iterations: 5);
+        act.Should().Throw<EvidenceTraceabilityException>()
+            .WithMessage("*Artifact not immutable*");
+    }
+
+    [Fact]
+    public void ArtifactImmutable_ThrowsWithLessThanTwoIterations()
+    {
+        var act = () => EvidenceChainAssert.ArtifactImmutable(() => "content", iterations: 1);
+        act.Should().Throw<ArgumentOutOfRangeException>();
+    }
+}