test(coverage): restore the ratchet under Coverlet 10

tests/AiDotNet.Evolution.Tests/UnitTests/EvolutionCoreParityTests.cs

@@ -14,6 +14,10 @@ public void RatioSelectionRejectsRatiosThatDoNotSumToOne()
         Assert.Throws<ArgumentException>(() => new RatioEvolutionSelectionPolicy<TestGenome>(options));
         Assert.Throws<ArgumentOutOfRangeException>(() => new RatioEvolutionSelectionPolicy<TestGenome>(
             new EvolutionSelectionOptions { ExplorationRatio = -1, ExploitationRatio = 1, EliteRatio = 1 }));
+        Assert.Throws<ArgumentOutOfRangeException>(() => new RatioEvolutionSelectionPolicy<TestGenome>(
+            new EvolutionSelectionOptions { ExplorationRatio = double.NaN, ExploitationRatio = 1, EliteRatio = 0 }));
+        Assert.Throws<ArgumentOutOfRangeException>(() => new RatioEvolutionSelectionPolicy<TestGenome>(
+            new EvolutionSelectionOptions { ExplorationRatio = 2, ExploitationRatio = 0, EliteRatio = 0 }));
     }
 
     [Fact]

tests/AiDotNet.Evolution.Tests/UnitTests/EvolutionDescriptorCalibrationTests.cs

@@ -111,8 +111,18 @@ public void InvalidCalibrationSettingsAreRefused()
             new EvolutionDescriptorCalibrationOptions { BinCount = 0 }.Validate());
         Assert.Throws<ArgumentOutOfRangeException>(() =>
             new EvolutionDescriptorCalibrationOptions { Padding = -1 }.Validate());
+        Assert.Throws<ArgumentOutOfRangeException>(() =>
+            new EvolutionDescriptorCalibrationOptions { Padding = double.NaN }.Validate());
+        Assert.Throws<ArgumentOutOfRangeException>(() =>
+            new EvolutionDescriptorCalibrationOptions { Padding = double.PositiveInfinity }.Validate());
+        Assert.Throws<ArgumentOutOfRangeException>(() =>
+            new EvolutionDescriptorCalibrationOptions { Padding = 101 }.Validate());
         Assert.Throws<ArgumentOutOfRangeException>(() =>
             new EvolutionDescriptorCalibrationOptions { DegenerateSpan = 0 }.Validate());
+        Assert.Throws<ArgumentOutOfRangeException>(() =>
+            new EvolutionDescriptorCalibrationOptions { DegenerateSpan = double.NaN }.Validate());
+        Assert.Throws<ArgumentOutOfRangeException>(() =>
+            new EvolutionDescriptorCalibrationOptions { DegenerateSpan = double.PositiveInfinity }.Validate());
         Assert.Throws<ArgumentOutOfRangeException>(() =>
             new EvolutionDescriptorCalibrationOptions
             {

tests/AiDotNet.Evolution.Tests/UnitTests/EvolutionMigrationTopologyTests.cs

@@ -98,6 +98,14 @@ public void AnInvalidTopologyOrRateIsRejectedByThePolicyAndByTheOptions()
         EvolutionEngineOptions badRate = Options(4, 4, islandCount: 2);
         badRate.MigrationRate = -0.5;
         Assert.Throws<ArgumentOutOfRangeException>(() => Engine(new SyntheticEvolutionTask(), badRate));
+
+        EvolutionEngineOptions nonFiniteRate = Options(4, 4, islandCount: 2);
+        nonFiniteRate.MigrationRate = double.NaN;
+        Assert.Throws<ArgumentOutOfRangeException>(() => Engine(new SyntheticEvolutionTask(), nonFiniteRate));
+
+        EvolutionEngineOptions excessiveRate = Options(4, 4, islandCount: 2);
+        excessiveRate.MigrationRate = 1.5;
+        Assert.Throws<ArgumentOutOfRangeException>(() => Engine(new SyntheticEvolutionTask(), excessiveRate));
     }
 
     [Fact]

tests/AiDotNet.Evolution.Tests/UnitTests/EvolutionPublicContractTests.cs

@@ -80,6 +80,10 @@ public void TraceRetentionCannotExceedPackageLevelResourceLimits()
         {
             ParentQualityCacheSize = EvolutionCollectionLimits.MaximumParentQualityCacheEntries + 1
         }.SnapshotAndValidate());
+        Assert.Throws<ArgumentOutOfRangeException>(() => new EvolutionTraceOptions
+        {
+            ParentQualityCacheSize = -1
+        }.SnapshotAndValidate());
     }
 
     [Fact]

tests/AiDotNet.Evolution.Tests/UnitTests/EvolutionSelectionPolicyTests.cs

@@ -5,6 +5,18 @@ namespace AiDotNet.Evolution.Tests;
 
 public sealed class EvolutionSelectionPolicyTests
 {
+    [Fact]
+    public void DoubleSelectionReturnsNullForAnEmptyArchive()
+    {
+        var archive = new MapElitesArchive<TestGenome>(new[]
+        {
+            new EvolutionDescriptorDefinition("x", 0, 4, 4)
+        });
+        var policy = new DoubleEvolutionSelectionPolicy<TestGenome>();
+
+        Assert.Null(policy.Select(archive, new StableRandom(3), inspirationCount: 3));
+    }
+
     [Fact]
     public void DoubleSelectionUsesDistinctQualityRankedInspirations()
     {

tests/AiDotNet.Evolution.Tests/UnitTests/MapElitesArchiveTests.cs

@@ -72,17 +72,27 @@ public void BoundedEvictionIsIndependentOfInsertionOrder()
     }
 
     [Fact]
-    public void InvalidEvaluationDoesNotEnterArchive()
+    public void InvalidEvaluationsDoNotEnterArchive()
     {
         MapElitesArchive<TestGenome> archive = Archive();
         (EvolutionCandidate<TestGenome> candidate, EvolutionEvaluation evaluation) = Create(1, "a", 1, 0.2);
-        var failed = new EvolutionEvaluation(1, "a", EvolutionEvaluationStatus.Failed, null,
-            EvolutionOptimizationDirection.Maximize, new Dictionary<string, double>(), Array.Empty<double>(),
-            Array.Empty<double>(), new EvolutionEvaluationCost(TimeSpan.Zero, 1, 0), evaluation.Lineage,
-            EvolutionCacheStatus.NotChecked, Array.Empty<EvolutionDiagnostic>(), "task", "eval", "config");
+        EvolutionEvaluation[] invalidEvaluations =
+        {
+            Invalid(EvolutionEvaluationStatus.Failed, null, EvolutionOptimizationDirection.Maximize, 1, "a"),
+            Invalid(EvolutionEvaluationStatus.Completed, 1, EvolutionOptimizationDirection.Minimize, 1, "a"),
+            Invalid(EvolutionEvaluationStatus.Completed, 1, EvolutionOptimizationDirection.Maximize, 2, "a"),
+            Invalid(EvolutionEvaluationStatus.Completed, 1, EvolutionOptimizationDirection.Maximize, 1, "other")
+        };
 
-        Assert.Equal(EvolutionArchiveInsertionResult.Rejected, archive.TryAdd(candidate, failed));
+        foreach (EvolutionEvaluation invalid in invalidEvaluations)
+            Assert.Equal(EvolutionArchiveInsertionResult.Rejected, archive.TryAdd(candidate, invalid));
         Assert.Empty(archive.Entries);
+
+        EvolutionEvaluation Invalid(EvolutionEvaluationStatus status, double? quality,
+            EvolutionOptimizationDirection direction, long evaluationId, string genomeId) => new(
+            evaluationId, genomeId, status, quality, direction, evaluation.Descriptors, Array.Empty<double>(),
+            Array.Empty<double>(), evaluation.Cost, evaluation.Lineage, EvolutionCacheStatus.NotChecked,
+            Array.Empty<EvolutionDiagnostic>(), "task", "eval", "config");
     }
 
     internal static MapElitesArchive<TestGenome> Archive(