service: allow MERGE method for Update Entity

Closes #103

Author: filak-sap

CHANGELOG.md

@@ -7,7 +7,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ## [Unreleased]
 
 ### Added
-- Specify PATCH or PUT method for EntityUpdateRequest - Barton Ip
+- Specify PATCH, PUT, or MERGE method for EntityUpdateRequest - Barton Ip
 - Add a Service wide configuration (e.g. http.update\_method) - Jakub Filak
 - <, <=, >, >= operators on GetEntitySetFilter - Barton Ip
 

pyodata/v2/service.py

@@ -512,17 +512,19 @@ class EntityModifyRequest(ODataHttpRequest):
        Call execute() to send the update-request to the OData service
        and get the modified entity."""
 
+    ALLOWED_HTTP_METHODS = ['PATCH', 'PUT', 'MERGE']
+
     def __init__(self, url, connection, handler, entity_set, entity_key, method="PATCH"):
         super(EntityModifyRequest, self).__init__(url, connection, handler)
         self._logger = logging.getLogger(LOGGER_NAME)
         self._entity_set = entity_set
         self._entity_type = entity_set.entity_type
         self._entity_key = entity_key
 
-        if method.upper() not in ["PATCH", "PUT"]:
-            raise ValueError("Method must be either PATCH or PUT")
-
-        self._method = method
+        self._method = method.upper()
+        if self._method not in EntityModifyRequest.ALLOWED_HTTP_METHODS:
+            raise ValueError('The value "{}" is not on the list of allowed Entity Update HTTP Methods: {}'
+                             .format(method, ', '.join(EntityModifyRequest.ALLOWED_HTTP_METHODS)))
 
         self._values = {}
 

tests/test_service_v2.py

@@ -687,6 +687,20 @@ def test_update_entity_with_patch_method_specified(service):
     query = service.entity_sets.TemperatureMeasurements.update_entity(key, method="PATCH")
     assert query.get_method() == "PATCH"
 
+def test_update_entity_with_merge_method_specified(service):
+    """Make sure the method update_entity handles correctly when MERGE method is specified"""
+
+    # pylint: disable=redefined-outer-name
+
+
+    key = EntityKey(
+        service.schema.entity_type('TemperatureMeasurement'),
+        Sensor='sensor1',
+        Date=datetime.datetime(2017, 12, 24, 18, 0))
+
+    query = service.entity_sets.TemperatureMeasurements.update_entity(key, method='merge')
+    assert query.get_method() == 'MERGE'
+
 
 def test_update_entity_with_no_method_specified(service):
     """Make sure the method update_entity handles correctly when no method is specified"""
@@ -730,8 +744,10 @@ def test_update_entity_with_wrong_method_specified(service):
         Sensor='sensor1',
         Date=datetime.datetime(2017, 12, 24, 18, 0))
 
-    with pytest.raises(ValueError):
-        service.entity_sets.TemperatureMeasurements.update_entity(key, method="DELETE")
+    with pytest.raises(ValueError) as caught_ex:
+        service.entity_sets.TemperatureMeasurements.update_entity(key, method='DELETE')
+
+    assert str(caught_ex.value).startswith('The value "DELETE" is not on the list of allowed Entity Update HTTP Methods: PATCH, PUT, MERGE')
 
 
 def test_get_entity_with_entity_key_and_other_params(service):