Fix qfactor rankings for HTTP-ACCEPT

graphene_django/tests/test_views.py

@@ -30,6 +30,20 @@ def response_json(response):
 def test_graphiql_is_enabled(client):
     response = client.get(url_string(), HTTP_ACCEPT='text/html')
     assert response.status_code == 200
+    assert response['Content-Type'].split(';')[0] == 'text/html'
+
+def test_qfactor_graphiql(client):
+    response = client.get(url_string(query='{test}'), HTTP_ACCEPT='application/json;q=0.8, text/html;q=0.9')
+    assert response.status_code == 200
+    assert response['Content-Type'].split(';')[0] == 'text/html'
+
+def test_qfactor_json(client):
+    response = client.get(url_string(query='{test}'), HTTP_ACCEPT='text/html;q=0.8, application/json;q=0.9')
+    assert response.status_code == 200
+    assert response['Content-Type'].split(';')[0] == 'application/json'
+    assert response_json(response) == {
+        'data': {'test': "Hello World"}
+    }
 
 
 def test_allows_get_with_query_param(client):

graphene_django/views.py

@@ -35,8 +35,8 @@ def qualify(x):
             match = re.match(r'(^|;)q=(0(\.\d{,3})?|1(\.0{,3})?)(;|$)',
                              parts[1])
             if match:
-                return parts[0], float(match.group(2))
-        return parts[0], 1
+                return parts[0].strip(), float(match.group(2))
+        return parts[0].strip(), 1
 
     raw_content_types = request.META.get('HTTP_ACCEPT', '*/*').split(',')
     qualified_content_types = map(qualify, raw_content_types)
@@ -280,10 +280,13 @@ def can_display_graphiql(cls, request, data):
     @classmethod
     def request_wants_html(cls, request):
         accepted = get_accepted_content_types(request)
-        html_index = accepted.count('text/html')
-        json_index = accepted.count('application/json')
+        accepted_length = len(accepted)
+        # the list will be ordered in preferred first - so we have to make
+        # sure the most preferred gets the highest number
+        html_priority = accepted_length - accepted.index('text/html') if 'text/html' in accepted else 0
+        json_priority = accepted_length - accepted.index('application/json') if 'application/json' in accepted else 0
 
-        return html_index > json_index
+        return html_priority > json_priority
 
     @staticmethod
     def get_graphql_params(request, data):