Added comprehensive unit tests

Author: amuraru

.github/workflows/ci.yaml

@@ -17,8 +17,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest]
-        python-version: ['3.10', '3.11', '3.12', '3.13', '3.14']
+        os: [ubuntu-latest, macos-latest]
+        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13', '3.14']
 
     steps:
     - name: Checkout code
@@ -65,7 +65,7 @@ jobs:
 
     - name: Upload coverage to Codecov
       if: matrix.os == 'ubuntu-latest' && matrix.python-version == '3.14'
-      uses: codecov/codecov-action@v3
+      uses: codecov/codecov-action@v4
       with:
         file: ./coverage.xml
         flags: unittests
@@ -159,7 +159,7 @@ jobs:
       uses: actions/checkout@v4
 
     - name: Set up Python
-      uses: actions/setup-python@v4
+      uses: actions/setup-python@v5
       with:
         python-version: '3.14'