Fix scheduling future actions (#237)

* Fix scheduling future actions

* add unit tests for sensor.utils datetime manipulations

src/sensor/tests/test_sensor_utils.py

@@ -0,0 +1,20 @@
+from datetime import datetime
+
+from django.conf import settings
+
+from sensor import utils
+
+
+def test_timestamp_manipulation():
+    now = datetime.now()
+    now_int = int(now.timestamp())
+    now_fromint = datetime.fromtimestamp(now_int)
+    now_str = now.strftime(settings.DATETIME_FORMAT)
+
+    test_dt_int = utils.get_timestamp_from_datetime(now)
+    test_dt_fromint = utils.get_datetime_from_timestamp(now_int)
+    test_dt_fromstr = utils.parse_datetime_str(now_str)
+
+    assert now_int == test_dt_int
+    assert now_fromint == test_dt_fromint
+    assert now == test_dt_fromstr

src/sensor/utils.py

@@ -9,16 +9,16 @@
 logger = logging.getLogger(__name__)
 
 
-def get_datetime_from_timestamp(ts):
+def get_datetime_from_timestamp(ts: int) -> datetime:
     return datetime.fromtimestamp(ts)
 
 
-def get_timestamp_from_datetime(dt: datetime):
+def get_timestamp_from_datetime(dt: datetime) -> int:
     """Assumes UTC datetime."""
-    return int(dt.strftime("%S"))
+    return int(dt.timestamp())
 
 
-def parse_datetime_str(d):
+def parse_datetime_str(d: str) -> datetime:
     return datetime.strptime(d, settings.DATETIME_FORMAT)