mobile: Add an endpoint for checking compatibility.

tools/lint-all

@@ -368,6 +368,7 @@ def build_custom_checkers(by_lang):
              ('zerver/middleware.py',
               'return json_error(exception.to_json_error_msg(), status=status_code)'),
              ('zerver/tornado/views.py', 'return json_error(result["message"])'),
+             ('zerver/views/compatibility.py', 'return json_error("Client is too old")'),
              ('zerver/views/invite.py',
               'return json_error(data=error_data, msg=ret_error)'),
              ('zerver/views/streams.py', 'return json_error(property_conversion)'),

zerver/tests/test_compatibility.py

@@ -0,0 +1,12 @@
+from __future__ import absolute_import
+from __future__ import print_function
+
+from zerver.lib.test_classes import ZulipTestCase
+
+class CompatibilityTest(ZulipTestCase):
+    def test_compatibility(self):
+        # type: () -> None
+        result = self.client_get("/compatibility", HTTP_USER_AGENT='ZulipMobile/5.0')
+        self.assert_json_success(result)
+        result = self.client_get("/compatibility", HTTP_USER_AGENT='ZulipInvalid/5.0')
+        self.assert_json_error(result, "Client is too old")

zerver/views/compatibility.py

@@ -0,0 +1,14 @@
+from __future__ import absolute_import
+
+from django.http import HttpResponse, HttpRequest
+from typing import Any, List, Dict, Optional, Text
+
+from zerver.lib.response import json_error, json_success
+from zerver.lib.user_agent import parse_user_agent
+
+def check_compatibility(request):
+    # type: (HttpRequest) -> HttpResponse
+    user_agent = parse_user_agent(request.META["HTTP_USER_AGENT"])
+    if user_agent['name'] == "ZulipInvalid":
+        return json_error("Client is too old")
+    return json_success()

zproject/urls.py

@@ -18,6 +18,7 @@ from django.contrib.auth.views import (login, password_reset,
 import zerver.tornado.views
 import zerver.views
 import zerver.views.auth
+import zerver.views.compatibility
 import zerver.views.home
 import zerver.views.registration
 import zerver.views.zephyr
@@ -351,6 +352,9 @@ urls += [
     # backends the server allows, to display the proper UI and check for server existence
     url(r'^api/v1/get_auth_backends', zerver.views.auth.api_get_auth_backends, name='zerver.views.auth.api_get_auth_backends'),
 
+    # used by mobile apps to check if they are compatible with the server
+    url(r'^compatibility$', zerver.views.compatibility.check_compatibility),
+
     # This json format view used by the mobile apps accepts a username
     # password/pair and returns an API key.
     url(r'^api/v1/fetch_api_key$', zerver.views.auth.api_fetch_api_key, name='zerver.views.auth.api_fetch_api_key'),