PB-847: Refactor item properties validation

Split validation function. Remove wrapper function
validate_item_properties_datetimes_dependencies.

app/stac_api/validators.py

@@ -364,36 +364,34 @@ def validate_geometry(geometry):
     return geometry
 
 
-def validate_item_properties_datetimes_dependencies(
+def validate_datetime_format(date_string):
+    try:
+        if date_string is not None and not isinstance(date_string, datetime):
+            return fromisoformat(date_string)
+        return date_string
+    except ValueError as error:
+        logger.error("Invalid datetime string %s", error)
+        raise ValidationError(
+            _('Invalid datetime string %(error)s'), params={'error': error}, code='invalid'
+        ) from error
+
+
+def validate_item_properties_datetimes(
     properties_datetime, properties_start_datetime, properties_end_datetime, properties_expires
 ):
     '''
-    Validate the dependencies between the Item datetimes properties
+    Validate the dependencies between the item datetime properties.
     This makes sure that either only the properties.datetime is set or
-    both properties.start_datetime and properties.end_datetime
+    both properties.start_datetime and properties.end_datetime are set.
+    If properties.expires is set, the value must be greater than
+    the properties.datetime or the properties.end_datetime.
     Raises:
         django.core.exceptions.ValidationError
     '''
-    try:
-        if not isinstance(properties_datetime, datetime) and properties_datetime is not None:
-            properties_datetime = fromisoformat(properties_datetime)
-        if (
-            not isinstance(properties_start_datetime, datetime) and
-            properties_start_datetime is not None
-        ):
-            properties_start_datetime = fromisoformat(properties_start_datetime)
-        if (
-            not isinstance(properties_end_datetime, datetime) and
-            properties_end_datetime is not None
-        ):
-            properties_end_datetime = fromisoformat(properties_end_datetime)
-        if not isinstance(properties_expires, datetime) and properties_expires is not None:
-            properties_expires = fromisoformat(properties_expires)
-    except ValueError as error:
-        logger.error("Invalid datetime string %s", error)
-        raise ValidationError(
-            _('Invalid datetime string %(error)s'), params={'error': error}, code='invalid'
-        ) from error
+    properties_datetime = validate_datetime_format(properties_datetime)
+    properties_start_datetime = validate_datetime_format(properties_start_datetime)
+    properties_end_datetime = validate_datetime_format(properties_end_datetime)
+    properties_expires = validate_datetime_format(properties_expires)
 
     if properties_datetime is not None:
         if (properties_start_datetime is not None or properties_end_datetime is not None):
@@ -405,7 +403,8 @@ def validate_item_properties_datetimes_dependencies(
             if properties_expires < properties_datetime:
                 message = "Property expires can't refer to a date earlier than property datetime"
                 raise ValidationError(_(message), code='invalid')
-    else:
+
+    if properties_datetime is None:
         if properties_end_datetime is None:
             message = "Property end_datetime can't be null when no property datetime is given"
             logger.error(message)
@@ -414,8 +413,6 @@ def validate_item_properties_datetimes_dependencies(
             message = "Property start_datetime can't be null when no property datetime is given"
             logger.error(message)
             raise ValidationError(_(message), code='invalid')
-
-    if properties_datetime is None:
         if properties_end_datetime < properties_start_datetime:
             message = "Property end_datetime can't refer to a date earlier than property "\
             "start_datetime"
@@ -427,20 +424,6 @@ def validate_item_properties_datetimes_dependencies(
                 raise ValidationError(_(message), code='invalid')
 
 
-def validate_item_properties_datetimes(
-    properties_datetime, properties_start_datetime, properties_end_datetime, properties_expires
-):
-    '''
-    Validate datetime values in the properties Item attributes
-    '''
-    validate_item_properties_datetimes_dependencies(
-        properties_datetime,
-        properties_start_datetime,
-        properties_end_datetime,
-        properties_expires,
-    )
-
-
 def validate_checksum_multihash_sha256(value):
     '''Validate the checksum multihash field
 

app/tests/tests_09/test_validators.py

@@ -5,7 +5,7 @@
 from stac_api.validators import get_media_type
 from stac_api.validators import normalize_and_validate_media_type
 from stac_api.validators import validate_content_encoding
-from stac_api.validators import validate_item_properties_datetimes_dependencies
+from stac_api.validators import validate_item_properties_datetimes
 
 
 class TestValidators(TestCase):
@@ -16,7 +16,7 @@ def test_validate_function_invalid_datetime_string(self):
             properties_start_datetime = "2001-22-66T08:00:00+00:00"
             properties_end_datetime = "2001-11-11T08:00:00+00:00"
             properties_expires = None
-            validate_item_properties_datetimes_dependencies(
+            validate_item_properties_datetimes(
                 properties_datetime,
                 properties_start_datetime,
                 properties_end_datetime,

app/tests/tests_10/test_item_model.py

@@ -98,6 +98,7 @@ def test_item_create_model_invalid_datetime(self):
             item.full_clean()
             item.save()
 
+    def test_item_create_model_invalid_datetime_order(self):
         with self.assertRaises(
             ValidationError, msg="end_datetime must not be earlier than start_datetime"
         ):

app/tests/tests_10/test_validators.py

@@ -9,7 +9,7 @@
 from stac_api.validators import get_media_type
 from stac_api.validators import normalize_and_validate_media_type
 from stac_api.validators import validate_content_encoding
-from stac_api.validators import validate_item_properties_datetimes_dependencies
+from stac_api.validators import validate_item_properties_datetimes
 
 from tests.tests_10.data_factory import Factory
 
@@ -22,7 +22,7 @@ def test_validate_function_invalid_datetime_string(self):
             properties_start_datetime = "2001-22-66T08:00:00+00:00"
             properties_end_datetime = "2001-11-11T08:00:00+00:00"
             properties_expires = None
-            validate_item_properties_datetimes_dependencies(
+            validate_item_properties_datetimes(
                 properties_datetime,
                 properties_start_datetime,
                 properties_end_datetime,