diff --git a/test.file b/test.file
deleted file mode 100644
index e69de29..0000000
diff --git a/test/common/unit/test_tools.py b/test/common/unit/test_tools.py
new file mode 100644
index 0000000..eebdab9
--- /dev/null
+++ b/test/common/unit/test_tools.py
@@ -0,0 +1,12 @@
+from common.tools import check_sha256_hex_format
+from test.common.unit.conftest import get_random_value_hex
+
+
+def test_check_sha256_hex_format():
+    # Only 32-byte hex encoded strings should pass the test
+    wrong_inputs = [None, str(), 213, 46.67, dict(), "A" * 63, "C" * 65, bytes(), get_random_value_hex(31)]
+    for wtype in wrong_inputs:
+        assert check_sha256_hex_format(wtype) is False
+
+    for v in range(100):
+        assert check_sha256_hex_format(get_random_value_hex(32)) is True