1 files changed, 72 insertions, 0 deletions
diff --git a/glucometerutils/support/tests/test_construct_extras.py b/glucometerutils/support/tests/test_construct_extras.py
new file mode 100644
index 0000000..6bba873
--- /dev/null
+++ b/glucometerutils/support/tests/test_construct_extras.py
@@ -0,0 +1,72 @@
+# -*- coding: utf-8 -*-
+#
+# SPDX-License-Identifier: MIT
+"""Tests for the common routines."""
+
+# pylint: disable=protected-access,missing-docstring
+
+import datetime
+
+import construct
+
+from absl.testing import absltest
+from glucometerutils.support import construct_extras
+
+_TEST_DATE1 = datetime.datetime(1970, 1, 2, 0, 0)
+_TEST_DATE2 = datetime.datetime(1971, 1, 1, 0, 0)
+_TEST_DATE3 = datetime.datetime(1970, 1, 1, 0, 0)
+
+_NEW_EPOCH = 31536000  # datetime.datetime(1971, 1, 1, 0, 0)
+
+
+class TestTimestamp(absltest.TestCase):
+    def test_build_unix_epoch(self):
+        self.assertEqual(
+            construct_extras.Timestamp(construct.Int32ul).build(_TEST_DATE1),
+            b"\x80\x51\x01\x00",
+        )
+
+    def test_parse_unix_epoch(self):
+        self.assertEqual(
+            construct_extras.Timestamp(construct.Int32ul).parse(b"\x803\xe1\x01"),
+            _TEST_DATE2,
+        )
+
+    def test_build_custom_epoch(self):
+        self.assertEqual(
+            construct_extras.Timestamp(construct.Int32ul, epoch=_NEW_EPOCH).build(
+                _TEST_DATE2
+            ),
+            b"\x00\x00\x00\x00",
+        )
+
+    def test_parse_custom_epoch(self):
+        self.assertEqual(
+            construct_extras.Timestamp(construct.Int32ul, epoch=_NEW_EPOCH).parse(
+                b"\x00\x00\x00\x00"
+            ),
+            _TEST_DATE2,
+        )
+
+    def test_build_custom_epoch_negative_failure(self):
+        with self.assertRaises(construct.core.FormatFieldError):
+            construct_extras.Timestamp(construct.Int32ul, epoch=_NEW_EPOCH).build(
+                _TEST_DATE1
+            )
+
+    def test_build_custom_epoch_negative_success(self):
+        self.assertEqual(
+            construct_extras.Timestamp(construct.Int32sl, epoch=_NEW_EPOCH).build(
+                _TEST_DATE1
+            ),
+            b"\x00\x1e\x20\xfe",
+        )
+
+    def test_build_varint(self):
+        self.assertEqual(
+            construct_extras.Timestamp(construct.VarInt).build(_TEST_DATE3), b"\x00"
+        )
+
+    def test_invalid_value(self):
+        with self.assertRaises(AssertionError):
+            construct_extras.Timestamp(construct.Int32ul).build("foo")