Refactor tests and project files for improved consistency and clarity

lib/momentum/ao/Ao.Quantower.Tests.cs

@@ -35,9 +35,9 @@ public class AoIndicatorTests
         var indicator = new AoIndicator { FastPeriod = 10, SlowPeriod = 40 };
         indicator.Initialize();
 
-        Assert.Contains("AO", indicator.ShortName);
-        Assert.Contains("10", indicator.ShortName);
-        Assert.Contains("40", indicator.ShortName);
+        Assert.Contains("AO", indicator.ShortName, StringComparison.Ordinal);
+        Assert.Contains("10", indicator.ShortName, StringComparison.Ordinal);
+        Assert.Contains("40", indicator.ShortName, StringComparison.Ordinal);
     }
 
     [Fact]
@@ -45,8 +45,8 @@ public class AoIndicatorTests
     {
         var indicator = new AoIndicator();
 
-        Assert.Contains("github.com", indicator.SourceCodeLink);
-        Assert.Contains("Ao.Quantower.cs", indicator.SourceCodeLink);
+        Assert.Contains("github.com", indicator.SourceCodeLink, StringComparison.Ordinal);
+        Assert.Contains("Ao.Quantower.cs", indicator.SourceCodeLink, StringComparison.Ordinal);
     }
 
     [Fact]

lib/momentum/ao/Ao.Validation.Tests.cs

@@ -69,10 +69,10 @@ public sealed class AoValidationTests : IDisposable
 
         var tulipIndicator = Tulip.Indicators.ao;
         double[][] inputs = { high, low };
-        double[] options = { };
+        double[] options = Array.Empty<double>();
 
         int lookback = 33;
-        double[][] outputs = { new double[_data.Bars.Count - lookback] };
+        double[][] outputs = [new double[_data.Bars.Count - lookback]];
 
         tulipIndicator.Run(inputs, options, outputs);
         var tulipResults = outputs[0];

lib/momentum/apo/Apo.Quantower.Tests.cs

@@ -35,9 +35,9 @@ public class ApoIndicatorTests
         var indicator = new ApoIndicator { FastPeriod = 10, SlowPeriod = 40 };
         indicator.Initialize();
 
-        Assert.Contains("APO", indicator.ShortName);
-        Assert.Contains("10", indicator.ShortName);
-        Assert.Contains("40", indicator.ShortName);
+        Assert.Contains("APO", indicator.ShortName, StringComparison.Ordinal);
+        Assert.Contains("10", indicator.ShortName, StringComparison.Ordinal);
+        Assert.Contains("40", indicator.ShortName, StringComparison.Ordinal);
     }
 
     [Fact]
@@ -45,8 +45,8 @@ public class ApoIndicatorTests
     {
         var indicator = new ApoIndicator();
 
-        Assert.Contains("github.com", indicator.SourceCodeLink);
-        Assert.Contains("Apo.Quantower.cs", indicator.SourceCodeLink);
+        Assert.Contains("github.com", indicator.SourceCodeLink, StringComparison.Ordinal);
+        Assert.Contains("Apo.Quantower.cs", indicator.SourceCodeLink, StringComparison.Ordinal);
     }
 
     [Fact]

lib/momentum/aroon/Aroon.Quantower.Tests.cs

@@ -34,8 +34,8 @@ public class AroonIndicatorTests
         var indicator = new AroonIndicator { Period = 20 };
         indicator.Initialize();
 
-        Assert.Contains("Aroon", indicator.ShortName);
-        Assert.Contains("20", indicator.ShortName);
+        Assert.Contains("Aroon", indicator.ShortName, StringComparison.Ordinal);
+        Assert.Contains("20", indicator.ShortName, StringComparison.Ordinal);
     }
 
     [Fact]
@@ -43,8 +43,8 @@ public class AroonIndicatorTests
     {
         var indicator = new AroonIndicator();
 
-        Assert.Contains("github.com", indicator.SourceCodeLink);
-        Assert.Contains("Aroon.Quantower.cs", indicator.SourceCodeLink);
+        Assert.Contains("github.com", indicator.SourceCodeLink, StringComparison.Ordinal);
+        Assert.Contains("Aroon.Quantower.cs", indicator.SourceCodeLink, StringComparison.Ordinal);
     }
 
     [Fact]

lib/momentum/aroonosc/AroonOsc.Quantower.Tests.cs

@@ -34,8 +34,8 @@ public class AroonOscIndicatorTests
         var indicator = new AroonOscIndicator { Period = 20 };
         indicator.Initialize();
 
-        Assert.Contains("AroonOsc", indicator.ShortName);
-        Assert.Contains("20", indicator.ShortName);
+        Assert.Contains("AroonOsc", indicator.ShortName, StringComparison.Ordinal);
+        Assert.Contains("20", indicator.ShortName, StringComparison.Ordinal);
     }
 
     [Fact]
@@ -43,8 +43,8 @@ public class AroonOscIndicatorTests
     {
         var indicator = new AroonOscIndicator();
 
-        Assert.Contains("github.com", indicator.SourceCodeLink);
-        Assert.Contains("AroonOsc.Quantower.cs", indicator.SourceCodeLink);
+        Assert.Contains("github.com", indicator.SourceCodeLink, StringComparison.Ordinal);
+        Assert.Contains("AroonOsc.Quantower.cs", indicator.SourceCodeLink, StringComparison.Ordinal);
     }
 
     [Fact]

lib/momentum/aroonosc/AroonOsc.Validation.Tests.cs

@@ -97,41 +97,4 @@ public sealed class AroonOscValidationTests : IDisposable
         ValidationHelper.VerifyData(results, tulipOsc, lookback: 14);
     }
 
-    [Fact(Skip = "Ooples implementation deviates significantly from standard (TA-Lib, Tulip, Skender, QuanTAlib)")]
-    public void MatchesOoples()
-    {
-        // Note: OoplesFinance implementation of Aroon Oscillator is an outlier.
-        // It deviates from the consensus of TA-Lib, Tulip, Skender, and QuanTAlib.
-        // The deviation is not a simple offset; it involves inconsistent steps and reversals,
-        // likely due to differences in how the high/low window indices are tracked.
-
-        var aroon = new AroonOsc(14);
-        var results = new List<double>();
-
-        for (int i = 0; i < _data.Bars.Count; i++)
-        {
-            var res = aroon.Update(_data.Bars[i]);
-            results.Add(res.Value);
-        }
-
-        var ooplesData = _data.SkenderQuotes.Select(q => new TickerData
-        {
-            Date = q.Date,
-            Open = (double)q.Open,
-            High = (double)q.High,
-            Low = (double)q.Low,
-            Close = (double)q.Close,
-            Volume = (double)q.Volume
-        }).ToList();
-
-        var stockData = new StockData(ooplesData);
-
-        // Ooples only provides CalculateAroonOscillator
-        var aroonOscResults = stockData.CalculateAroonOscillator(14);
-        var ooplesOsc = aroonOscResults.OutputValues["Aroon"]
-            .ToArray();
-
-        // Verify Oscillator
-        ValidationHelper.VerifyData(results, ooplesOsc, lookback: 14, tolerance: ValidationHelper.OoplesTolerance);
-    }
 }

lib/momentum/bop/Bop.Quantower.Tests.cs

@@ -40,8 +40,8 @@ public class BopIndicatorTests
     {
         var indicator = new BopIndicator();
 
-        Assert.Contains("github.com", indicator.SourceCodeLink);
-        Assert.Contains("Bop.Quantower.cs", indicator.SourceCodeLink);
+        Assert.Contains("github.com", indicator.SourceCodeLink, StringComparison.Ordinal);
+        Assert.Contains("Bop.Quantower.cs", indicator.SourceCodeLink, StringComparison.Ordinal);
     }
 
     [Fact]

lib/momentum/bop/Bop.Validation.Tests.cs

@@ -62,7 +62,7 @@ public sealed class BopValidationTests : IDisposable
         var close = _data.Bars.Close.Values.ToArray();
         
         double[][] inputs = { open, high, low, close };
-        double[] options = { }; // No options for BOP
+        double[] options = Array.Empty<double>(); // No options for BOP
 
         var bopInd = Tulip.Indicators.bop;
         double[][] outputs = { new double[open.Length - bopInd.Start(options)] };

lib/momentum/cfb/Cfb.Quantower.Tests.cs

@@ -38,9 +38,9 @@ public class CfbIndicatorTests
         // Initialize to update SourceName
         indicator.Initialize();
 
-        Assert.Contains("CFB", indicator.ShortName);
-        Assert.Contains("5-20", indicator.ShortName);
-        Assert.Contains("Close", indicator.ShortName);
+        Assert.Contains("CFB", indicator.ShortName, StringComparison.Ordinal);
+        Assert.Contains("5-20", indicator.ShortName, StringComparison.Ordinal);
+        Assert.Contains("Close", indicator.ShortName, StringComparison.Ordinal);
     }
 
     [Fact]
@@ -48,8 +48,8 @@ public class CfbIndicatorTests
     {
         var indicator = new CfbIndicator();
 
-        Assert.Contains("github.com", indicator.SourceCodeLink);
-        Assert.Contains("Cfb.Quantower.cs", indicator.SourceCodeLink);
+        Assert.Contains("github.com", indicator.SourceCodeLink, StringComparison.Ordinal);
+        Assert.Contains("Cfb.Quantower.cs", indicator.SourceCodeLink, StringComparison.Ordinal);
     }
 
     [Fact]

lib/momentum/dmx/Dmx.Quantower.Tests.cs

@@ -35,8 +35,8 @@ public class DmxIndicatorTests
         // Initialize to update SourceName (though DMX doesn't use SourceName)
         indicator.Initialize();
 
-        Assert.Contains("DMX", indicator.ShortName);
-        Assert.Contains("20", indicator.ShortName);
+        Assert.Contains("DMX", indicator.ShortName, StringComparison.Ordinal);
+        Assert.Contains("20", indicator.ShortName, StringComparison.Ordinal);
     }
 
     [Fact]
@@ -44,8 +44,8 @@ public class DmxIndicatorTests
     {
         var indicator = new DmxIndicator();
 
-        Assert.Contains("github.com", indicator.SourceCodeLink);
-        Assert.Contains("Dmx.Quantower.cs", indicator.SourceCodeLink);
+        Assert.Contains("github.com", indicator.SourceCodeLink, StringComparison.Ordinal);
+        Assert.Contains("Dmx.Quantower.cs", indicator.SourceCodeLink, StringComparison.Ordinal);
     }
 
     [Fact]

lib/momentum/macd/Macd.Quantower.Tests.cs

@@ -49,8 +49,8 @@ public class MacdIndicatorTests
     {
         var indicator = new MacdIndicator();
 
-        Assert.Contains("github.com", indicator.SourceCodeLink);
-        Assert.Contains("Macd.Quantower.cs", indicator.SourceCodeLink);
+        Assert.Contains("github.com", indicator.SourceCodeLink, StringComparison.Ordinal);
+        Assert.Contains("Macd.Quantower.cs", indicator.SourceCodeLink, StringComparison.Ordinal);
     }
 
     [Fact]

lib/momentum/rsi/Rsi.Quantower.Tests.cs

@@ -39,7 +39,7 @@ public class RsiIndicatorTests
         };
         indicator.Initialize();
 
-        Assert.Contains("RSI(20)", indicator.ShortName);
+        Assert.Contains("RSI(20)", indicator.ShortName, StringComparison.Ordinal);
     }
 
     [Fact]
@@ -47,8 +47,8 @@ public class RsiIndicatorTests
     {
         var indicator = new RsiIndicator();
 
-        Assert.Contains("github.com", indicator.SourceCodeLink);
-        Assert.Contains("Rsi.Quantower.cs", indicator.SourceCodeLink);
+        Assert.Contains("github.com", indicator.SourceCodeLink, StringComparison.Ordinal);
+        Assert.Contains("Rsi.Quantower.cs", indicator.SourceCodeLink, StringComparison.Ordinal);
     }
 
     [Fact]

lib/momentum/rsi/Rsi.Tests.cs

@@ -1,63 +1,261 @@
-using Xunit;
 using System;
+using System.Collections.Generic;
+using Xunit;
 
-namespace QuanTAlib.Tests;
+namespace QuanTAlib;
 
 public class RsiTests
 {
     [Fact]
-    public void BasicCalculation()
+    public void Constructor_InvalidParameters_ThrowsArgumentException()
+    {
+        Assert.Throws<ArgumentException>(() => new Rsi(0));
+        Assert.Throws<ArgumentException>(() => new Rsi(-1));
+    }
+
+    [Fact]
+    public void BasicCalculation_DoesNotCrash()
     {
         var rsi = new Rsi(14);
-        // RSI requires a period of data to be valid
+        var gbm = new GBM();
+        var series = gbm.Fetch(1000, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
+
+        for (int i = 0; i < series.Count; i++)
+        {
+            rsi.Update(series.Close[i]);
+        }
+
+        Assert.True(double.IsFinite(rsi.Last.Value));
+    }
+
+    [Fact]
+    public void Properties_Accessible()
+    {
+        var rsi = new Rsi(14);
+        Assert.Equal("Rsi(14)", rsi.Name);
         Assert.False(rsi.IsHot);
+        Assert.Equal(0, rsi.Last.Value);
     }
 
     [Fact]
-    public void BatchMatchesStreaming()
+    public void IsHot_BecomesTrueAfterWarmup()
     {
-        var rsi = new Rsi(5);
-        var series = new TSeries();
-        // Generate some data
-        for (int i = 0; i < 20; i++)
+        var rsi = new Rsi(14);
+        var gbm = new GBM();
+        var series = gbm.Fetch(50, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
+
+        Assert.False(rsi.IsHot);
+
+        // RSI wraps two RMA indicators (gain and loss)
+        // RMA wraps EMA with alpha = 1/period
+        // EMA becomes hot when E <= 0.05, which occurs after ~-ln(0.05)/ln(1-alpha) values
+        // For period=14: alpha=1/14, needs ~40 values to become hot
+        // Both RMAs must be hot for RSI to be hot
+        for (int i = 0; i < 45; i++)
         {
-            series.Add(new TValue(DateTime.UtcNow.AddMinutes(i), 100 + Math.Sin(i) * 10));
+            rsi.Update(series.Close[i]);
+            if (i < 40)
+            {
+                Assert.False(rsi.IsHot, $"Should not be hot at index {i}");
+            }
         }
 
-        var batchResult = rsi.Update(series);
-        
+        // After sufficient warmup, IsHot should be true
+        Assert.True(rsi.IsHot);
+    }
+
+    [Fact]
+    public void IsNew_True_AdvancesState()
+    {
+        var rsi = new Rsi(5);
+        var gbm = new GBM();
+        var series = gbm.Fetch(10, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
+
+        for (int i = 0; i < 9; i++)
+        {
+            rsi.Update(series.Close[i], isNew: true);
+        }
+
+        var val1 = rsi.Update(series.Close[9], isNew: true);
+        var nextTime = series.Close[9].Time + TimeSpan.FromMinutes(1).Ticks;
+        var val2 = rsi.Update(new TValue(nextTime, series.Close[9].Value + 1), isNew: true);
+
+        Assert.NotEqual(val1.Value, val2.Value);
+    }
+
+    [Fact]
+    public void IsNew_False_UpdatesCurrentBar()
+    {
+        var rsi = new Rsi(5);
+        var gbm = new GBM();
+        var series = gbm.Fetch(10, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
+
+        for (int i = 0; i < 9; i++)
+        {
+            rsi.Update(series.Close[i]);
+        }
+
+        var val1 = rsi.Update(series.Close[9], isNew: true);
+        var modifiedValue = new TValue(series.Close[9].Time, series.Close[9].Value + 5);
+        var val2 = rsi.Update(modifiedValue, isNew: false);
+
+        // Should update the same bar
+        Assert.Equal(val1.Time, val2.Time);
+        Assert.NotEqual(val1.Value, val2.Value);
+    }
+
+    [Fact]
+    public void IsNew_Consistency()
+    {
+        var rsi = new Rsi(14);
+        var gbm = new GBM();
+        var series = gbm.Fetch(100, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
+
+        // Feed first 99
+        for (int i = 0; i < 99; i++)
+        {
+            rsi.Update(series.Close[i]);
+        }
+
+        // Update with 100th point (isNew=true)
+        rsi.Update(series.Close[99], true);
+
+        // Update with modified 100th point (isNew=false)
+        var modifiedValue = new TValue(series.Close[99].Time, series.Close[99].Value + 2.0);
+        var val2 = rsi.Update(modifiedValue, false);
+
+        // Create new instance and feed up to modified
+        var rsi2 = new Rsi(14);
+        for (int i = 0; i < 99; i++)
+        {
+            rsi2.Update(series.Close[i]);
+        }
+        var val3 = rsi2.Update(modifiedValue, true);
+
+        Assert.Equal(val3.Value, val2.Value, 1e-9);
+    }
+
+    [Fact]
+    public void IterativeCorrections_RestoreToOriginalState()
+    {
+        var rsi = new Rsi(10);
+        var gbm = new GBM();
+        var series = gbm.Fetch(50, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
+
+        // Feed N values
+        for (int i = 0; i < 30; i++)
+        {
+            rsi.Update(series.Close[i]);
+        }
+
+        var originalValue = rsi.Last;
+
+        // Make M updates with isNew=false
+        for (int m = 0; m < 5; m++)
+        {
+            var modifiedValue = new TValue(series.Close[29].Time, series.Close[29].Value + m);
+            rsi.Update(modifiedValue, isNew: false);
+        }
+
+        // Restore with original 30th value
+        var restoredValue = rsi.Update(series.Close[29], isNew: false);
+
+        Assert.Equal(originalValue.Value, restoredValue.Value, 1e-9);
+    }
+
+    [Fact]
+    public void Reset_ClearsState()
+    {
+        var rsi = new Rsi(14);
+        var gbm = new GBM();
+        var series = gbm.Fetch(100, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
+
+        for (int i = 0; i < series.Count; i++)
+        {
+            rsi.Update(series.Close[i]);
+        }
+
+        Assert.True(rsi.IsHot);
+        var valueBefore = rsi.Last.Value;
+
         rsi.Reset();
-        var streamResults = new System.Collections.Generic.List<double>();
-        foreach (var item in series)
+
+        Assert.False(rsi.IsHot);
+        Assert.Equal(0, rsi.Last.Value);
+
+        // Feed again
+        for (int i = 0; i < series.Count; i++)
         {
-            streamResults.Add(rsi.Update(item).Value);
+            rsi.Update(series.Close[i]);
         }
 
-        for (int i = 0; i < series.Count; i++)
-        {
-            Assert.Equal(batchResult[i].Value, streamResults[i], 8);
-        }
+        Assert.True(rsi.IsHot);
+        Assert.Equal(valueBefore, rsi.Last.Value, 1e-9);
     }
-    
+
     [Fact]
-    public void SpanMatchesBatch()
+    public void NaN_Input_DoesNotCrash()
     {
-        var rsi = new Rsi(5);
-        var series = new TSeries();
-        // Generate some data
+        var rsi = new Rsi(10);
+        var gbm = new GBM();
+        var series = gbm.Fetch(20, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
+
+        for (int i = 0; i < 15; i++)
+        {
+            rsi.Update(series.Close[i]);
+        }
+
+        // Feed NaN
+        var nanValue = new TValue(DateTime.UtcNow, double.NaN);
+        var result = rsi.Update(nanValue);
+
+        // Should not crash and should return finite value
+        Assert.True(double.IsFinite(result.Value));
+    }
+
+    [Fact]
+    public void Infinity_Input_DoesNotCrash()
+    {
+        var rsi = new Rsi(10);
+        var gbm = new GBM();
+        var series = gbm.Fetch(20, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
+
+        for (int i = 0; i < 15; i++)
+        {
+            rsi.Update(series.Close[i]);
+        }
+
+        var infValue = new TValue(DateTime.UtcNow, double.PositiveInfinity);
+        var result = rsi.Update(infValue);
+
+        Assert.True(double.IsFinite(result.Value));
+    }
+
+    [Fact]
+    public void MultipleNaN_ContinuesCorrectly()
+    {
+        var rsi = new Rsi(10);
+        var gbm = new GBM();
+        var series = gbm.Fetch(30, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
+
         for (int i = 0; i < 20; i++)
         {
-            series.Add(new TValue(DateTime.UtcNow.AddMinutes(i), 100 + Math.Sin(i) * 10));
+            rsi.Update(series.Close[i]);
         }
-        
-        var batchResult = rsi.Update(series);
-        
-        var output = new double[series.Count];
-        Rsi.Calculate(series.Values, output, 5);
-        
-        for (int i = 0; i < series.Count; i++)
+
+        // Feed multiple NaN
+        for (int i = 0; i < 5; i++)
         {
-            Assert.Equal(batchResult[i].Value, output[i], 8);
+            var nanValue = new TValue(DateTime.UtcNow.AddMinutes(i), double.NaN);
+            var result = rsi.Update(nanValue);
+            Assert.True(double.IsFinite(result.Value));
+        }
+
+        // Continue with valid data
+        for (int i = 20; i < 30; i++)
+        {
+            var result = rsi.Update(series.Close[i]);
+            Assert.True(double.IsFinite(result.Value));
         }
     }
 
@@ -72,24 +270,170 @@ public class RsiTests
         }
 
         var result = rsi.Update(series);
-        // Flat line means no gains or losses, RSI should be 50 (or 0/100 depending on implementation details, but typically 50 or 0 if no moves)
-        // Actually, if AvgGain=0 and AvgLoss=0, RSI is typically defined as 50 or 0.
-        // Our implementation: RS = 0/0 -> NaN?
-        // Let's check implementation.
-        // If AvgLoss is 0, RSI is 100.
-        // If AvgGain is 0, RSI is 0.
-        // If both are 0?
-        // In Rma: if all inputs are 0, Rma is 0.
-        // So AvgGain=0, AvgLoss=0.
-        // RS = 0/0 = NaN.
-        // RSI = 100 - 100/(1+NaN) = NaN.
-        // Let's see what happens.
-        
-        // Actually, standard behavior for flat line is often 50 or 0.
-        // Let's verify what our implementation does.
-        // If we look at Rsi.cs:
-        // if (avgLoss == 0) return avgGain == 0 ? 50 : 100;
         
+        // Flat line: no gains or losses, RSI = 50
         Assert.Equal(50, result.Last.Value);
     }
+
+    [Fact]
+    public void TSeries_Update_Matches_Streaming()
+    {
+        var rsi = new Rsi(14);
+        var gbm = new GBM();
+        var series = gbm.Fetch(200, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
+
+        var streamingResults = new List<double>();
+        for (int i = 0; i < series.Count; i++)
+        {
+            streamingResults.Add(rsi.Update(series.Close[i]).Value);
+        }
+
+        var rsi2 = new Rsi(14);
+        var seriesResults = rsi2.Update(series.Close);
+
+        Assert.Equal(streamingResults.Count, seriesResults.Count);
+        for (int i = 0; i < seriesResults.Count; i++)
+        {
+            Assert.Equal(streamingResults[i], seriesResults.Values[i], 1e-9);
+        }
+    }
+
+    [Fact]
+    public void StaticBatch_Matches_Streaming()
+    {
+        var gbm = new GBM();
+        var series = gbm.Fetch(200, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
+
+        var rsi = new Rsi(14);
+        var streamingResults = new List<double>();
+        for (int i = 0; i < series.Count; i++)
+        {
+            streamingResults.Add(rsi.Update(series.Close[i]).Value);
+        }
+
+        var batchResults = Rsi.Batch(series.Close, 14);
+
+        Assert.Equal(streamingResults.Count, batchResults.Count);
+        for (int i = 0; i < batchResults.Count; i++)
+        {
+            Assert.Equal(streamingResults[i], batchResults.Values[i], 1e-9);
+        }
+    }
+
+    [Fact]
+    public void SpanCalc_ValidatesInput()
+    {
+        var source = new double[10];
+        var output = new double[5];
+
+        Assert.Throws<ArgumentException>(() => Rsi.Calculate(source, output, 14));
+    }
+
+    [Fact]
+    public void SpanCalc_InvalidPeriod_Throws()
+    {
+        var source = new double[10];
+        var output = new double[10];
+
+        Assert.Throws<ArgumentException>(() => Rsi.Calculate(source, output, 0));
+        Assert.Throws<ArgumentException>(() => Rsi.Calculate(source, output, -1));
+    }
+
+    [Fact]
+    public void SpanCalc_MatchesTSeriesCalc()
+    {
+        var gbm = new GBM();
+        var series = gbm.Fetch(200, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
+
+        var batchResults = Rsi.Batch(series.Close, 14);
+
+        var output = new double[series.Count];
+        Rsi.Calculate(series.Close.Values, output, 14);
+
+        for (int i = 0; i < output.Length; i++)
+        {
+            Assert.Equal(batchResults.Values[i], output[i], 1e-9);
+        }
+    }
+
+    [Fact]
+    public void SpanCalc_HandlesNaN()
+    {
+        var source = new double[20];
+        var gbm = new GBM();
+        var series = gbm.Fetch(20, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
+        
+        for (int i = 0; i < 20; i++)
+        {
+            source[i] = series.Close[i].Value;
+        }
+        
+        source[10] = double.NaN;
+        source[15] = double.NaN;
+
+        var output = new double[20];
+        Rsi.Calculate(source, output, 10);
+
+        // Should not crash and produce finite results
+        for (int i = 0; i < output.Length; i++)
+        {
+            Assert.True(double.IsFinite(output[i]) || output[i] == 0);
+        }
+    }
+
+    [Fact]
+    public void AllModes_ProduceSameResult()
+    {
+        int period = 14;
+        var gbm = new GBM();
+        var series = gbm.Fetch(200, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
+
+        // 1. Batch Mode
+        var batchSeries = Rsi.Batch(series.Close, period);
+        double expected = batchSeries.Last.Value;
+
+        // 2. Span Mode
+        var spanOutput = new double[series.Count];
+        Rsi.Calculate(series.Close.Values, spanOutput, period);
+        double spanResult = spanOutput[^1];
+
+        // 3. Streaming Mode
+        var streamingRsi = new Rsi(period);
+        for (int i = 0; i < series.Count; i++)
+        {
+            streamingRsi.Update(series.Close[i]);
+        }
+        double streamingResult = streamingRsi.Last.Value;
+
+        // 4. Eventing Mode
+        var pubSource = new TSeries();
+        var eventingRsi = new Rsi(pubSource, period);
+        for (int i = 0; i < series.Count; i++)
+        {
+            pubSource.Add(series.Close[i]);
+        }
+        double eventingResult = eventingRsi.Last.Value;
+
+        // Assert
+        Assert.Equal(expected, spanResult, 9);
+        Assert.Equal(expected, streamingResult, 9);
+        Assert.Equal(expected, eventingResult, 9);
+    }
+
+    [Fact]
+    public void Chainability_Works()
+    {
+        var rsi = new Rsi(14);
+        var gbm = new GBM();
+        var series = gbm.Fetch(10, DateTime.UtcNow.Ticks, TimeSpan.FromMinutes(1));
+
+        // Test TSeries chain
+        var result = rsi.Update(series.Close);
+        Assert.NotNull(result);
+        Assert.IsType<TSeries>(result);
+
+        // Test TValue chain (returns TValue)
+        var result2 = rsi.Update(series.Close[0]);
+        Assert.IsType<TValue>(result2);
+    }
 }

lib/momentum/rsx/Rsx.Quantower.Tests.cs

@@ -34,8 +34,8 @@ public class RsxIndicatorTests
     {
         var indicator = new RsxIndicator { Period = 15 };
 
-        Assert.Contains("RSX", indicator.ShortName);
-        Assert.Contains("15", indicator.ShortName);
+        Assert.Contains("RSX", indicator.ShortName, StringComparison.Ordinal);
+        Assert.Contains("15", indicator.ShortName, StringComparison.Ordinal);
     }
 
     [Fact]
@@ -43,8 +43,8 @@ public class RsxIndicatorTests
     {
         var indicator = new RsxIndicator();
 
-        Assert.Contains("github.com", indicator.SourceCodeLink);
-        Assert.Contains("Rsx.Quantower.cs", indicator.SourceCodeLink);
+        Assert.Contains("github.com", indicator.SourceCodeLink, StringComparison.Ordinal);
+        Assert.Contains("Rsx.Quantower.cs", indicator.SourceCodeLink, StringComparison.Ordinal);
     }
 
     [Fact]

lib/momentum/vel/Vel.Quantower.Tests.cs

@@ -34,8 +34,8 @@ public class VelIndicatorTests
     {
         var indicator = new VelIndicator { Period = 15 };
 
-        Assert.Contains("VEL", indicator.ShortName);
-        Assert.Contains("15", indicator.ShortName);
+        Assert.Contains("VEL", indicator.ShortName, StringComparison.Ordinal);
+        Assert.Contains("15", indicator.ShortName, StringComparison.Ordinal);
     }
 
     [Fact]
@@ -43,8 +43,8 @@ public class VelIndicatorTests
     {
         var indicator = new VelIndicator();
 
-        Assert.Contains("github.com", indicator.SourceCodeLink);
-        Assert.Contains("Vel.Quantower.cs", indicator.SourceCodeLink);
+        Assert.Contains("github.com", indicator.SourceCodeLink, StringComparison.Ordinal);
+        Assert.Contains("Vel.Quantower.cs", indicator.SourceCodeLink, StringComparison.Ordinal);
     }
 
     [Fact]