Optional parameters can be omitted from payload.

CHANGES.rst

@@ -6,6 +6,7 @@ Version 0.2.0
 
 To be released.
 
+- Made parameters having an optional type possible to be omitted. [`#205`_]
 - Added method dispatching by querystring pattern
   e.g., ``@http-resource(method="GET", path="/users?from={from}&to={to}")``.
   [`#130`_]
@@ -21,6 +22,7 @@ To be released.
 - ``WsgiApp.url_map`` attribute was gone.
 - ``/ping/`` resource was gone.
 
+.. _#205: https://github.com/spoqa/nirum/issues/205
 .. _#130: https://github.com/spoqa/nirum/issues/130
 .. _CORS: https://www.w3.org/TR/cors/
 

nirum_wsgi.py

@@ -10,6 +10,7 @@
 import re
 import typing
 
+from nirum._compat import get_union_types, is_union_type
 from nirum.datastructures import List
 from nirum.deserialize import deserialize_meta
 from nirum.exc import (NirumProcedureArgumentRequiredError,
@@ -30,7 +31,7 @@
     'PathMatch', 'ServiceMethodError',
     'UriTemplateMatchResult', 'UriTemplateMatcher',
     'WsgiApp',
-    'match_request', 'parse_json_payload',
+    'is_optional_type', 'match_request', 'parse_json_payload',
 )
 MethodDispatch = collections.namedtuple('MethodDispatch', [
     'request', 'routed', 'service_method',
@@ -44,6 +45,20 @@
 ])
 
 
+def is_optional_type(type_):
+    # it have to be removed after nirum._compat.is_optional_type added.
+    return is_union_type(type_) and type(None) in get_union_types(type_)
+
+
+def _get_argument_value(payload, key, type_):
+    if key in payload or is_optional_type(type_):
+        return payload.get(key)
+    else:
+        raise NirumProcedureArgumentRequiredError(
+            "A argument named '{}' is missing, it is required.".format(key)
+        )
+
+
 def match_request(rules, request_method, path_info, querystring):
     # Ignore root path.
     if path_info == '/':
@@ -395,14 +410,7 @@ def _parse_procedure_arguments(self, type_hints, request_json):
             if version >= 2:
                 type_ = type_()
             behind_name = name_map[argument_name]
-            try:
-                data = request_json[behind_name]
-            except KeyError:
-                raise NirumProcedureArgumentRequiredError(
-                    "A argument named '{}' is missing, it is required.".format(
-                        behind_name
-                    )
-                )
+            data = _get_argument_value(request_json, behind_name, type_=type_)
             try:
                 arguments[argument_name] = deserialize_meta(type_, data)
             except ValueError:

schema-fixture/fixture.nrm

@@ -64,6 +64,12 @@ service statistics-service (
         path="/statistics/purchases/?from={from}&to={to}&interval={interval}"
     )
     [int64] purchase-interval (date from, date to, bigint interval),
+
+    @http-resource(
+        method="GET",
+        path="/statistics/daily-purchases/?ez={exclude}"
+    )
+    [int64] daily-purchase (bool? exclude),
 );
 
 unboxed token (uuid);

tests.py

@@ -65,6 +65,14 @@ def purchase_count(self, from_, to):
     def purchase_interval(self, from_, to, interval):
         return list(range(int(interval)))
 
+    def daily_purchase(self, exclude):
+        if exclude is None:
+            return [1]
+        elif exclude:
+            return [1, 2]
+        else:
+            return [1, 2, 3]
+
 
 @fixture
 def fx_music_wsgi():
@@ -519,3 +527,22 @@ def test_resolve_querystring(qs, expected):
         typing.Sequence[int], json.loads(response.get_data(as_text=True))
     )
     assert return_result == expected
+
+
+@mark.parametrize('payload, expected', [
+    ({'exclude': False}, [1, 2, 3]),
+    ({'exclude': True}, [1, 2]),
+    ({'exclude': None}, [1]),
+    ({}, [1]),
+])
+def test_omit_optional_parameter(payload, expected):
+    app = WsgiApp(StatisticsServiceImpl())
+    client = Client(app, Response)
+    response = client.post(
+        '/?method=daily_purchase',
+        data=json.dumps(payload),
+        content_type='application/json'
+    )
+    assert response.status_code == 200, response.get_data(as_text=True)
+    actual = json.loads(response.get_data(as_text=True))
+    assert actual == expected