Preserving the multiplicity of array type query parameters (#500)

* Preserving the multiplicity of array type query parameters

* Resolved failing tests, and refactored code block into a method

* Added tests for multi array

* Refactored parameter.py and updated tests in test_parameters.py

connexion/decorators/parameter.py

@@ -105,6 +105,23 @@ def sanitize_param(name):
             name = snake_and_shadow(name)
         return name and re.sub('^[^a-zA-Z_]+', '', re.sub('[^0-9a-zA-Z_]', '', name))
 
+    def make_request_query(request):
+        request_query = {}
+        try:
+            for k, v in request.query.to_dict(flat=False).items():
+                k = sanitize_param(k)
+                query_param = query_types.get(k, None)
+                if query_param is not None and query_param["type"] == "array":
+                    if query_param.get("collectionFormat", None) == "pipes":
+                        request_query[k] = "|".join(v)
+                    else:
+                        request_query[k] = ",".join(v)
+                else:
+                    request_query[k] = v[0]
+        except AttributeError:
+            request_query = {sanitize_param(k): v for k, v in request.form.items()}
+        return request_query
+
     body_parameters = [parameter for parameter in parameters if parameter['in'] == 'body'] or [{}]
     body_name = sanitize_param(body_parameters[0].get('name'))
     default_body = body_parameters[0].get('schema', {}).get('default')
@@ -150,7 +167,7 @@ def wrapper(request):
 
         # Add query parameters
         query_arguments = copy.deepcopy(default_query_params)
-        query_arguments.update({sanitize_param(k): v for k, v in request.query.items()})
+        query_arguments.update(make_request_query(request))
         for key, value in query_arguments.items():
             if not has_kwargs and key not in arguments:
                 logger.debug("Query Parameter '%s' not in function arguments", key)

tests/api/test_parameters.py

@@ -54,6 +54,14 @@ def test_array_query_param(simple_app):
     response = app_client.get(url, headers=headers)
     array_response = json.loads(response.data.decode('utf-8', 'replace'))  # [str] unsupported collectionFormat
     assert array_response == ["1;2;3"]
+    url = '/v1.0/test_array_csv_query_param?items=A&items=B&items=C&items=D,E,F'
+    response = app_client.get(url, headers=headers)
+    array_response = json.loads(response.data.decode('utf-8', 'replace'))  # type: [str] multi array with csv format
+    assert array_response == ['A', 'B', 'C', 'D', 'E', 'F']
+    url = '/v1.0/test_array_pipes_query_param?items=4&items=5&items=6&items=7|8|9'
+    response = app_client.get(url, headers=headers)
+    array_response = json.loads(response.data.decode('utf-8', 'replace'))  # type: [int] multi array with pipes format
+    assert array_response == [4, 5, 6, 7, 8, 9]
 
 
 def test_extra_query_param(simple_app):