diff --git a/tests/test_ytils_utils.py b/tests/test_ytils_utils.py
new file mode 100644
index 000000000..c10f1dcd3
--- /dev/null
+++ b/tests/test_ytils_utils.py
@@ -0,0 +1,85 @@
+import pytest
+import sys
+import os
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
+from slic.utils.utils import *
+
+
+# Test singleton()
+
+@singleton
+class test_singleton_class:
+    def __init__(self):
+        self.value = 123
+
+    def get(self):
+        return self.value
+
+def test_singleton_instance():
+    # To verify that it's not a class but an instance, and that the instance has a 'get' method
+    assert isinstance(test_singleton_class, object)
+    assert hasattr(test_singleton_class, "get")
+
+    assert test_singleton_class.get() == 123
+    assert test_singleton_class.value == 123
+
+def test_singleton_identity():
+    # Re-accessing the singleton returns same instance
+    ref = test_singleton_class
+    assert ref is test_singleton_class
+
+# Test: typename()
+
+@pytest.mark.parametrize("obj,expected", [
+    (42, "int"),
+    ("hello", "str"),
+    (test_singleton_class, "test_singleton_class"),
+])
+def test_typename(obj, expected):
+    assert typename(obj) == expected
+
+# Test: next_int()
+
+@pytest.mark.parametrize("nums,expected", [
+    ([1, 2, 3], 4),
+    ([10, 20], 21),
+    ([], 0),
+])
+def test_next_int(nums, expected):
+    assert next_int(nums) == expected
+
+# Test zero_pad()
+
+@pytest.mark.parametrize("i,n,expected", [
+    (7, 3, "007"),
+    (123, 5, "00123"),
+    (0, 2, "00"),
+])
+def test_zero_pad(i, n, expected):
+    assert zero_pad(i, n) == expected
+
+# Test iround()
+
+@pytest.mark.parametrize("val,expected", [
+    (3.6, 4),
+    (2.1, 2),
+    (-1.5, -2),
+    (-1.4, -1),
+])
+def test_iround(val, expected):
+    assert iround(val) == expected
+
+# Test: sorted_naturally
+
+@pytest.mark.parametrize("items,expected", [
+    (["file1", "file10", "file2"], ["file1", "file2", "file10"]),
+    (["z9", "z10", "z2", "z1"], ["z1", "z2", "z9", "z10"]),
+])
+def test_sorted_naturally(items, expected):
+    assert sorted_naturally(items) == expected
+
+@pytest.mark.parametrize("items,expected", [
+    (["file1", "file10", "file2"], ["file10", "file2", "file1"]),
+])
+def test_sorted_naturally_reverse(items, expected):
+    assert sorted_naturally(items, reverse=True) == expected