up

src/Policy/__Tests/StellaOps.Policy.Tests/PolicyValidationCliTests.cs

@@ -1,7 +1,6 @@
 using System;
 using System.IO;
 using System.Threading.Tasks;
-using FluentAssertions;
 using StellaOps.Policy;
 using Xunit;
 
@@ -42,10 +41,10 @@ public class PolicyValidationCliTests
 
             var exit = await cli.RunAsync(options);
 
-            exit.Should().Be(0);
+            Assert.Equal(0, exit);
             var text = output.ToString();
-            text.Should().Contain("OK");
-            text.Should().Contain("canonical.spl.digest:");
+            Assert.Contains("OK", text, StringComparison.Ordinal);
+            Assert.Contains("canonical.spl.digest:", text, StringComparison.Ordinal);
         }
         finally
         {

src/Policy/__Tests/StellaOps.Policy.Tests/Scoring/EvidenceFreshnessCalculatorTests.cs

@@ -0,0 +1,54 @@
+using Xunit;
+
+namespace StellaOps.Policy.Tests.Scoring;
+
+public sealed class EvidenceFreshnessCalculatorTests
+{
+    [Theory]
+    [InlineData(0, 10000)]
+    [InlineData(7, 10000)]
+    [InlineData(8, 9000)]
+    [InlineData(30, 9000)]
+    [InlineData(31, 7500)]
+    [InlineData(90, 7500)]
+    [InlineData(91, 6000)]
+    [InlineData(180, 6000)]
+    [InlineData(181, 4000)]
+    [InlineData(365, 4000)]
+    [InlineData(366, 2000)]
+    public void CalculateMultiplierBps_UsesExpectedBucketBoundaries(int ageDays, int expectedMultiplierBps)
+    {
+        var calculator = new StellaOps.Policy.Scoring.EvidenceFreshnessCalculator();
+        var asOf = new DateTimeOffset(2025, 01, 01, 0, 0, 0, TimeSpan.Zero);
+        var evidenceTimestamp = asOf.AddDays(-ageDays);
+
+        var multiplier = calculator.CalculateMultiplierBps(evidenceTimestamp, asOf);
+
+        Assert.Equal(expectedMultiplierBps, multiplier);
+    }
+
+    [Fact]
+    public void CalculateMultiplierBps_FutureTimestampReturnsMaxFreshness()
+    {
+        var calculator = new StellaOps.Policy.Scoring.EvidenceFreshnessCalculator();
+        var asOf = new DateTimeOffset(2025, 01, 01, 0, 0, 0, TimeSpan.Zero);
+        var evidenceTimestamp = asOf.AddDays(1);
+
+        var multiplier = calculator.CalculateMultiplierBps(evidenceTimestamp, asOf);
+
+        Assert.Equal(10000, multiplier);
+    }
+
+    [Fact]
+    public void ApplyFreshness_UsesBasisPointMath()
+    {
+        var calculator = new StellaOps.Policy.Scoring.EvidenceFreshnessCalculator();
+        var asOf = new DateTimeOffset(2025, 01, 01, 0, 0, 0, TimeSpan.Zero);
+        var evidenceTimestamp = asOf.AddDays(-30);
+
+        var adjusted = calculator.ApplyFreshness(100, evidenceTimestamp, asOf);
+
+        Assert.Equal(90, adjusted);
+    }
+}
+

src/Policy/__Tests/StellaOps.Policy.Tests/Scoring/ScoreExplainBuilderTests.cs

@@ -0,0 +1,41 @@
+using Xunit;
+
+namespace StellaOps.Policy.Tests.Scoring;
+
+public sealed class ScoreExplainBuilderTests
+{
+    [Fact]
+    public void Build_SortsDeterministically()
+    {
+        var builder = new StellaOps.Policy.Scoring.ScoreExplainBuilder()
+            .Add("provenance", 10, "p", digests: new[] { "sha256:b" })
+            .Add("reachability", 90, "r", digests: new[] { "sha256:c" })
+            .Add("evidence", 20, "e", digests: new[] { "sha256:a" })
+            .Add("evidence", 21, "e2", digests: new[] { "sha256:0", "sha256:z" });
+
+        var explanations = builder.Build();
+
+        Assert.Collection(explanations,
+            item => Assert.Equal("evidence", item.Factor),
+            item => Assert.Equal("evidence", item.Factor),
+            item => Assert.Equal("provenance", item.Factor),
+            item => Assert.Equal("reachability", item.Factor));
+        Assert.Equal("sha256:0", explanations[0].ContributingDigests?[0]);
+        Assert.Equal("sha256:a", explanations[1].ContributingDigests?[0]);
+    }
+
+    [Fact]
+    public void AddEvidence_ComputesAdjustedValueDeterministically()
+    {
+        var builder = new StellaOps.Policy.Scoring.ScoreExplainBuilder()
+            .AddEvidence(points: 80, freshnessMultiplierBps: 7500, ageDays: 90);
+
+        var explanations = builder.Build();
+
+        Assert.Single(explanations);
+        Assert.Equal("evidence", explanations[0].Factor);
+        Assert.Equal(60, explanations[0].Value);
+        Assert.Contains("90 days old", explanations[0].Reason);
+    }
+}
+