diff --git a/README.md b/README.md
index d371819..a1e2a47 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 [![Build](https://github.com/rmontanana/mdlp/actions/workflows/build.yml/badge.svg)](https://github.com/rmontanana/mdlp/actions/workflows/build.yml)
 [![Quality Gate Status](https://sonarcloud.io/api/project_badges/measure?project=rmontanana_mdlp&metric=alert_status)](https://sonarcloud.io/summary/new_code?id=rmontanana_mdlp)
 [![Reliability Rating](https://sonarcloud.io/api/project_badges/measure?project=rmontanana_mdlp&metric=reliability_rating)](https://sonarcloud.io/summary/new_code?id=rmontanana_mdlp)
-[![Coverage Badge](https://img.shields.io/badge/Coverage-96,1%25-green)](html/index.html)
+[![Coverage Badge](https://img.shields.io/badge/Coverage-100,0%25-green)](html/index.html)
 [![Ask DeepWiki](https://deepwiki.com/badge.svg)](https://deepwiki.com/rmontanana/mdlp)
 [![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.14245443.svg)](https://doi.org/10.5281/zenodo.14245443)
 
diff --git a/src/BinDisc.cpp b/src/BinDisc.cpp
index 096fddf..06d61ab 100644
--- a/src/BinDisc.cpp
+++ b/src/BinDisc.cpp
@@ -49,7 +49,7 @@ namespace mdlp {
         // Note: y parameter is validated but not used in binning strategy
         fit(X);
     }
-    std::vector<precision_t> linspace(precision_t start, precision_t end, int num)
+    std::vector<precision_t> BinDisc::linspace(precision_t start, precision_t end, int num)
     {
         // Input validation
         if (num < 2) {
@@ -77,7 +77,7 @@ namespace mdlp {
     {
         return std::max(lower, std::min(n, upper));
     }
-    std::vector<precision_t> percentile(samples_t& data, const std::vector<precision_t>& percentiles)
+    std::vector<precision_t> BinDisc::percentile(samples_t& data, const std::vector<precision_t>& percentiles)
     {
         // Input validation
         if (data.empty()) {
diff --git a/src/BinDisc.h b/src/BinDisc.h
index 0a082be..abe239e 100644
--- a/src/BinDisc.h
+++ b/src/BinDisc.h
@@ -23,6 +23,9 @@ namespace mdlp {
         // y is included for compatibility with the Discretizer interface
         void fit(samples_t& X_, labels_t& y) override;
         void fit(samples_t& X);
+    protected:
+        std::vector<precision_t> linspace(precision_t start, precision_t end, int num);
+        std::vector<precision_t> percentile(samples_t& data, const std::vector<precision_t>& percentiles);
     private:
         void fit_uniform(const samples_t&);
         void fit_quantile(const samples_t&);
diff --git a/src/CPPFImdlp.h b/src/CPPFImdlp.h
index 7a8c0ab..4c48198 100644
--- a/src/CPPFImdlp.h
+++ b/src/CPPFImdlp.h
@@ -39,8 +39,8 @@ namespace mdlp {
         size_t getCandidate(size_t, size_t);
         size_t compute_max_num_cut_points() const;
         pair<precision_t, size_t> valueCutPoint(size_t, size_t, size_t);
-    private:
-        inline precision_t safe_X_access(size_t idx) const {
+        inline precision_t safe_X_access(size_t idx) const
+        {
             if (idx >= indices.size()) {
                 throw std::out_of_range("Index out of bounds for indices array");
             }
@@ -50,7 +50,8 @@ namespace mdlp {
             }
             return X[real_idx];
         }
-        inline label_t safe_y_access(size_t idx) const {
+        inline label_t safe_y_access(size_t idx) const
+        {
             if (idx >= indices.size()) {
                 throw std::out_of_range("Index out of bounds for indices array");
             }
@@ -60,7 +61,8 @@ namespace mdlp {
             }
             return y[real_idx];
         }
-        inline size_t safe_subtract(size_t a, size_t b) const {
+        inline size_t safe_subtract(size_t a, size_t b) const
+        {
             if (b > a) {
                 throw std::underflow_error("Subtraction would cause underflow");
             }
diff --git a/tests/BinDisc_unittest.cpp b/tests/BinDisc_unittest.cpp
index 0102a45..5d43c7b 100644
--- a/tests/BinDisc_unittest.cpp
+++ b/tests/BinDisc_unittest.cpp
@@ -11,6 +11,16 @@
 #include <ArffFiles.hpp>
 #include "BinDisc.h"
 #include "Experiments.hpp"
+#include <cmath>
+
+#define EXPECT_THROW_WITH_MESSAGE(stmt, etype, whatstring) EXPECT_THROW( \
+try { \
+stmt; \
+} catch (const etype& ex) { \
+EXPECT_EQ(whatstring, std::string(ex.what())); \
+throw; \
+} \
+, etype)
 
 namespace mdlp {
     const float margin = 1e-4;
@@ -400,4 +410,64 @@ namespace mdlp {
         }
         // std::cout << "* Number of experiments tested: " << num << std::endl;
     }
+
+    TEST_F(TestBinDisc3U, FitDataSizeTooSmall)
+    {
+        // Test when data size is smaller than n_bins
+        samples_t X = { 1.0, 2.0 }; // Only 2 elements for 3 bins
+        EXPECT_THROW_WITH_MESSAGE(fit(X), std::invalid_argument, "Input data size must be at least equal to n_bins");
+    }
+
+    TEST_F(TestBinDisc3Q, FitDataSizeTooSmall)
+    {
+        // Test when data size is smaller than n_bins
+        samples_t X = { 1.0, 2.0 }; // Only 2 elements for 3 bins
+        EXPECT_THROW_WITH_MESSAGE(fit(X), std::invalid_argument, "Input data size must be at least equal to n_bins");
+    }
+
+    TEST_F(TestBinDisc3U, FitWithYEmptyX)
+    {
+        // Test fit(X, y) with empty X
+        samples_t X = {};
+        labels_t y = { 1, 2, 3 };
+        EXPECT_THROW_WITH_MESSAGE(fit(X, y), std::invalid_argument, "X cannot be empty");
+    }
+
+    TEST_F(TestBinDisc3U, LinspaceInvalidNumPoints)
+    {
+        // Test linspace with num < 2
+        EXPECT_THROW_WITH_MESSAGE(linspace(0.0f, 1.0f, 1), std::invalid_argument, "Number of points must be at least 2 for linspace");
+    }
+
+    TEST_F(TestBinDisc3U, LinspaceNaNValues)
+    {
+        // Test linspace with NaN values
+        float nan_val = std::numeric_limits<float>::quiet_NaN();
+        EXPECT_THROW_WITH_MESSAGE(linspace(nan_val, 1.0f, 3), std::invalid_argument, "Start and end values cannot be NaN");
+        EXPECT_THROW_WITH_MESSAGE(linspace(0.0f, nan_val, 3), std::invalid_argument, "Start and end values cannot be NaN");
+    }
+
+    TEST_F(TestBinDisc3U, LinspaceInfiniteValues)
+    {
+        // Test linspace with infinite values
+        float inf_val = std::numeric_limits<float>::infinity();
+        EXPECT_THROW_WITH_MESSAGE(linspace(inf_val, 1.0f, 3), std::invalid_argument, "Start and end values cannot be infinite");
+        EXPECT_THROW_WITH_MESSAGE(linspace(0.0f, inf_val, 3), std::invalid_argument, "Start and end values cannot be infinite");
+    }
+
+    TEST_F(TestBinDisc3U, PercentileEmptyData)
+    {
+        // Test percentile with empty data
+        samples_t empty_data = {};
+        std::vector<precision_t> percentiles = { 25.0f, 50.0f, 75.0f };
+        EXPECT_THROW_WITH_MESSAGE(percentile(empty_data, percentiles), std::invalid_argument, "Data cannot be empty for percentile calculation");
+    }
+
+    TEST_F(TestBinDisc3U, PercentileEmptyPercentiles)
+    {
+        // Test percentile with empty percentiles
+        samples_t data = { 1.0f, 2.0f, 3.0f };
+        std::vector<precision_t> empty_percentiles = {};
+        EXPECT_THROW_WITH_MESSAGE(percentile(data, empty_percentiles), std::invalid_argument, "Percentiles cannot be empty");
+    }
 }
diff --git a/tests/FImdlp_unittest.cpp b/tests/FImdlp_unittest.cpp
index 6712d64..b364712 100644
--- a/tests/FImdlp_unittest.cpp
+++ b/tests/FImdlp_unittest.cpp
@@ -373,4 +373,55 @@ namespace mdlp {
             EXPECT_EQ(computed_ft[i], expected[i]);
         }
     }
+    TEST_F(TestFImdlp, SafeXAccessIndexOutOfBounds)
+    {
+        // Test safe_X_access with index out of bounds for indices array
+        X = { 1.0f, 2.0f, 3.0f };
+        y = { 1, 2, 3 };
+        indices = { 0, 1 }; // shorter than expected
+
+        // This should trigger the first exception in safe_X_access (idx >= indices.size())
+        EXPECT_THROW_WITH_MESSAGE(safe_X_access(2), std::out_of_range, "Index out of bounds for indices array");
+    }
+
+    TEST_F(TestFImdlp, SafeXAccessXOutOfBounds)
+    {
+        // Test safe_X_access with real_idx out of bounds for X array
+        X = { 1.0f, 2.0f }; // shorter array
+        y = { 1, 2, 3 };
+        indices = { 0, 1, 5 }; // indices[2] = 5 is out of bounds for X
+
+        // This should trigger the second exception in safe_X_access (real_idx >= X.size())
+        EXPECT_THROW_WITH_MESSAGE(safe_X_access(2), std::out_of_range, "Index out of bounds for X array");
+    }
+
+    TEST_F(TestFImdlp, SafeYAccessIndexOutOfBounds)
+    {
+        // Test safe_y_access with index out of bounds for indices array
+        X = { 1.0f, 2.0f, 3.0f };
+        y = { 1, 2, 3 };
+        indices = { 0, 1 }; // shorter than expected
+
+        // This should trigger the first exception in safe_y_access (idx >= indices.size())
+        EXPECT_THROW_WITH_MESSAGE(safe_y_access(2), std::out_of_range, "Index out of bounds for indices array");
+    }
+
+    TEST_F(TestFImdlp, SafeYAccessYOutOfBounds)
+    {
+        // Test safe_y_access with real_idx out of bounds for y array
+        X = { 1.0f, 2.0f, 3.0f };
+        y = { 1, 2 }; // shorter array
+        indices = { 0, 1, 5 }; // indices[2] = 5 is out of bounds for y
+
+        // This should trigger the second exception in safe_y_access (real_idx >= y.size())
+        EXPECT_THROW_WITH_MESSAGE(safe_y_access(2), std::out_of_range, "Index out of bounds for y array");
+    }
+
+    TEST_F(TestFImdlp, SafeSubtractUnderflow)
+    {
+        // Test safe_subtract with underflow condition (b > a)
+        EXPECT_THROW_WITH_MESSAGE(safe_subtract(3, 5), std::underflow_error, "Subtraction would cause underflow");
+    }
+
+
 }