add utils module tests

Author: chrissimpkins

tests/test_utils.py

@@ -0,0 +1,21 @@
+import os
+import re
+
+from fdiff.utils import get_file_modtime, file_exists
+
+import pytest
+
+
+def test_get_file_modtime():
+    modtime = get_file_modtime(os.path.join("tests", "testfiles", "test.txt"))
+    assert modtime.startswith("2019-09-04T") is True
+    regex = re.compile(r"""\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d+-\d{2}:\d{2}""")
+    assert regex.fullmatch(modtime) is not None
+
+
+def test_file_exists_true():
+    assert file_exists(os.path.join("tests", "testfiles", "test.txt")) is True
+
+
+def test_file_exists_false():
+    assert file_exists(os.path.join("tests", "testfiles", "bogus.jpg")) is False