Refactor code structure for improved readability and maintainability; removed redundant code blocks and optimized function calls.

src/Scanner/__Tests/StellaOps.Scanner.Emit.Tests/Reachability/ReachabilityLatticeTests.cs

@@ -0,0 +1,88 @@
+using FluentAssertions;
+using StellaOps.Scanner.Emit.Reachability;
+using Xunit;
+
+namespace StellaOps.Scanner.Emit.Tests.Reachability;
+
+public class ReachabilityLatticeTests
+{
+    [Fact]
+    public void StaticPath_YieldsConditional()
+    {
+        var result = ReachabilityLattice.Evaluate(new[]
+        {
+            new ReachabilityEvidence(ReachabilityEvidenceKind.StaticPath, "path1")
+        });
+
+        result.State.Should().Be(ReachabilityState.Conditional);
+        result.Score.Should().Be(0.5);
+    }
+
+    [Fact]
+    public void RuntimeHit_PromotesReachableAndAddsBonus()
+    {
+        var result = ReachabilityLattice.Evaluate(new[]
+        {
+            new ReachabilityEvidence(ReachabilityEvidenceKind.StaticPath),
+            new ReachabilityEvidence(ReachabilityEvidenceKind.RuntimeHit)
+        });
+
+        result.State.Should().Be(ReachabilityState.Reachable);
+        result.Score.Should().Be(0.8);
+    }
+
+    [Fact]
+    public void RuntimeSinkHit_AddsAdditionalBonus()
+    {
+        var result = ReachabilityLattice.Evaluate(new[]
+        {
+            new ReachabilityEvidence(ReachabilityEvidenceKind.RuntimeHit),
+            new ReachabilityEvidence(ReachabilityEvidenceKind.RuntimeSinkHit)
+        });
+
+        result.State.Should().Be(ReachabilityState.Reachable);
+        result.Score.Should().Be(1.0);
+    }
+
+    [Fact]
+    public void Guard_DemotesWhenNoRuntimeEvidence()
+    {
+        var result = ReachabilityLattice.Evaluate(new[]
+        {
+            new ReachabilityEvidence(ReachabilityEvidenceKind.StaticPath),
+            new ReachabilityEvidence(ReachabilityEvidenceKind.Guard)
+        });
+
+        result.State.Should().Be(ReachabilityState.Unknown);
+        result.Score.Should().Be(0.3);
+    }
+
+    [Fact]
+    public void Mitigation_SetsUnreachableWhenNoRuntime()
+    {
+        var result = ReachabilityLattice.Evaluate(new[]
+        {
+            new ReachabilityEvidence(ReachabilityEvidenceKind.StaticPath),
+            new ReachabilityEvidence(ReachabilityEvidenceKind.Mitigation)
+        });
+
+        result.State.Should().Be(ReachabilityState.Unreachable);
+        result.Score.Should().Be(0.2);
+    }
+
+    [Fact]
+    public void OrderIndependentAndRounded()
+    {
+        var shuffled = new[]
+        {
+            new ReachabilityEvidence(ReachabilityEvidenceKind.Guard),
+            new ReachabilityEvidence(ReachabilityEvidenceKind.StaticPath),
+            new ReachabilityEvidence(ReachabilityEvidenceKind.RuntimeHit),
+        };
+
+        var result = ReachabilityLattice.Evaluate(shuffled);
+
+        result.State.Should().Be(ReachabilityState.Reachable);
+        result.Score.Should().Be(0.8);
+    }
+}