diff --git a/tests/unit/utils/test_byte_to_bits.py b/tests/unit/utils/test_byte_to_bits.py
new file mode 100644
index 0000000..227667a
--- /dev/null
+++ b/tests/unit/utils/test_byte_to_bits.py
@@ -0,0 +1,28 @@
+from src.jeb_utils.utils import byte_to_bits
+import pytest
+
+@pytest.mark.parametrize('b,expected', [
+    (b'\x00', (0, 0, 0, 0, 0, 0, 0, 0)),
+    (b'\x01', (0, 0, 0, 0, 0, 0, 0, 1)),
+    (b'\x80', (1, 0, 0, 0, 0, 0, 0, 0)),
+    (b'\xf0', (1, 1, 1, 1, 0, 0, 0, 0)),
+    (b'\xff', (1, 1, 1, 1, 1, 1, 1, 1)),
+])
+def test_byte_to_bits(b, expected):
+    assert byte_to_bits(b) == expected
+
+@pytest.mark.parametrize('b,expected_exception', [
+    (b'\x00\x00', ValueError),
+    (b'\x00\x01', ValueError),
+    (b'\x01\x00', ValueError),
+    (b'\xff\xff', ValueError),
+    (b'\xff\x00', ValueError),
+    (b'\x00\xff', ValueError),
+    (b'\x42\x2a', ValueError),
+    (b'\x00\x42\x2a', ValueError),
+    (b'\x25\x42\x2a', ValueError),
+    (b'Hello, World!', ValueError),
+])
+def test_byte_to_bits(b, expected_exception):
+    with pytest.raises(expected_exception):
+        byte_to_bits(b)
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