fix: handle errors while parsing dates in filters

There were error, handling the returned value of the date string
parser. Problem was that the parser could return None value which was
compared against other None or date which obviously does not compute.

Solution to this is to fail early on the parser function and handle the
error correctly where the parser function is used.
This lead to writing error handling to the MaybeRelativeDateField since
the viewset using the function was correctly handling errors (just not
the None values).

Before this, when giving badly formatted date parameter in the
dateperiod end would have been okay and all the periods would be
returned - not anymore, now it returns a validation error.

Refs HAUKI-564

hours/filters.py

@@ -4,6 +4,7 @@
 
 from dateutil.parser import parse
 from dateutil.relativedelta import MO, SU, relativedelta
+from django.core.exceptions import ValidationError as DjangoValidationError
 from django.db.models import Q
 from django.forms import Field
 from django.utils import timezone
@@ -75,10 +76,7 @@ def parse_maybe_relative_date_string(
         return today + relativedelta(**relativedelta_params)
 
     # Try to parse the exact date
-    try:
-        return parse(date_string, fuzzy=False).date()
-    except ValueError:
-        return None
+    return parse(date_string, fuzzy=False).date()
 
 
 class MaybeRelativeDateField(Field):
@@ -95,7 +93,10 @@ def to_python(self, value):
 
         value = value.strip()
 
-        return parse_maybe_relative_date_string(value, end_date=self.end_date)
+        try:
+            return parse_maybe_relative_date_string(value, end_date=self.end_date)
+        except ValueError:
+            raise DjangoValidationError("Invalid date format")
 
 
 class MaybeRelativeNullableDateFilter(Filter):

hours/tests/test_dateperiod_api.py

@@ -10,6 +10,18 @@
 from hours.tests.utils import assert_response_status_code
 
 
+@pytest.mark.django_db
+def test_invalid_format_returns_400(admin_client):
+    url = reverse("date_period-list")
+
+    response = admin_client.get(url, data={"start_date_lte": "2030-101-01"})
+
+    assert response.status_code == 400, "{} {}".format(
+        response.status_code, response.data
+    )
+    assert response.data["start_date_lte"][0] == "Invalid date format"
+
+
 @pytest.mark.django_db
 def test_list_date_periods_empty(admin_client):
     url = reverse("date_period-list")

hours/tests/test_opening_hours_api.py

@@ -2,6 +2,28 @@
 
 import pytest
 from django.urls import reverse
+from django.utils.translation import gettext_lazy as _
+
+
+@pytest.mark.django_db
+def test_opening_hours_invalid_date(admin_client):
+    url = reverse("opening_hours-list")
+
+    data = {
+        "start_date": "2020-101-01",
+        "end_date": "2020-11-30",
+    }
+
+    response = admin_client.get(
+        url,
+        data=data,
+        content_type="application/json",
+    )
+
+    assert response.status_code == 400, "{} {}".format(
+        response.status_code, response.data
+    )
+    assert response.data[0] == _("Invalid start_date")
 
 
 @pytest.mark.django_db

hours/tests/test_parse_filter_date.py

@@ -85,3 +85,8 @@
 def test_parse_filter_date(input_string, end_date, frozen_date, expected_date):
     with freeze_time(frozen_date):
         assert parse_maybe_relative_date_string(input_string, end_date) == expected_date
+
+
+def test_parse_errors():
+    with pytest.raises(ValueError):
+        parse_maybe_relative_date_string("2020-101-3")