diff --git a/Solverz/num_api/test/test_my_module_parser.py b/Solverz/num_api/test/test_my_module_parser.py
deleted file mode 100644
index e69de29..0000000
diff --git a/Solverz/num_api/test/test_udm.py b/Solverz/num_api/test/test_udm.py
new file mode 100644
index 0000000..b713401
--- /dev/null
+++ b/Solverz/num_api/test/test_udm.py
@@ -0,0 +1,75 @@
+"""
+Test the user defined modules.
+"""
+
+import importlib
+import os
+import re
+import shutil
+from pathlib import Path
+
+import pytest
+
+from Solverz.num_api.user_function_parser import add_my_module, reset_my_module_paths
+
+mymodule_code = """import numpy as np
+from numba import njit
+
+
+@njit(cache=True)
+def c(x, y):
+    x = np.asarray(x).reshape((-1,))
+    y = np.asarray(y).reshape((-1,))
+
+    z = np.zeros_like(x)
+
+    for i in range(len(x)):
+        if x[i] <= y[i]:
+            z[i] = x[i]
+        else:
+            z[i] = y[i]
+    return z
+"""
+
+
+def test_udm():
+    # Create a .Solverz_test_temp directory in the user's home directory
+    user_home = str(Path.home())
+    solverz_dir = os.path.join(user_home, '.Solverz_test_temp')
+
+    # Create the .Solverz directory if it does not exist
+    if not os.path.exists(solverz_dir):
+        os.makedirs(solverz_dir)
+
+    file_path = os.path.join(solverz_dir, r'your_module.py')
+    file_path1 = os.path.join(solverz_dir, r'fake1.jl')
+
+    # Write the new paths to the file, but only if they are not already present
+    with open(file_path, 'a') as file:
+        file.write(mymodule_code)
+
+    with open(file_path1, 'a') as file:
+        file.write(mymodule_code)
+
+    with pytest.raises(ValueError,
+                       match=re.escape(f"The path {solverz_dir} is not a file.")):
+        add_my_module([solverz_dir])
+
+    with pytest.raises(ValueError,
+                       match=re.escape(f"The path {os.path.join(user_home, '.Solverz_test_temp1')} does not exist.")):
+        add_my_module([os.path.join(user_home, '.Solverz_test_temp1')])
+
+    with pytest.raises(ValueError,
+                       match=re.escape(f"The file {file_path1} is not a Python file.")):
+        add_my_module([file_path1])
+
+    add_my_module([file_path])
+
+    import Solverz
+    importlib.reload(Solverz.num_api.module_parser)
+    from Solverz.num_api.module_parser import your_module
+    import numpy as np
+    np.testing.assert_allclose(your_module.c(np.array([1, 0]), np.array([2, -1])), np.array([1, -1]))
+
+    shutil.rmtree(solverz_dir)
+    reset_my_module_paths()
diff --git a/Solverz/num_api/user_function_parser.py b/Solverz/num_api/user_function_parser.py
index 247ccd3..f10c5df 100644
--- a/Solverz/num_api/user_function_parser.py
+++ b/Solverz/num_api/user_function_parser.py
@@ -16,13 +16,13 @@ def validate_module_paths(paths):
         if not os.path.exists(path):
             raise ValueError(f"The path {path} does not exist.")
 
-            # Check if the path is a file
-            if not os.path.isfile(path):
-                raise ValueError(f"The path {path} is not a file.")
+        # Check if the path is a file
+        if not os.path.isfile(path):
+            raise ValueError(f"The path {path} is not a file.")
 
-            # Check if the file is a Python file
-            if not path.endswith('.py'):
-                raise ValueError(f"The file {path} is not a Python file.")
+        # Check if the file is a Python file
+        if not path.endswith('.py'):
+            raise ValueError(f"The file {path} is not a Python file.")
 
         # If all checks pass, add the path to the valid paths list
         valid_paths.append(path)
@@ -38,12 +38,9 @@ def add_my_module(paths, filename='user_modules.txt'):
         :param paths: List of user-provided module paths
         :param filename: Name of the file to save, default is 'user_modules.txt'
         """
-    try:
-        # Validate paths
-        validated_paths = validate_module_paths(paths)
-    except ValueError as e:
-        print(e)
-        return
+
+    # Validate paths
+    validated_paths = validate_module_paths(paths)
 
     # Get the path to the .Solverz directory in the user's home directory
     user_home = str(Path.home())