Handling FCM canonical error codes (#131)

Author: hiranya911

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Unreleased
 
--
+- [changed] Improved error handling in FCM by mapping more server-side
+  errors to client-side error codes.
 
 # v2.9.0
 

firebase_admin/messaging.py

@@ -716,11 +716,18 @@ class _MessagingService(object):
     INTERNAL_ERROR = 'internal-error'
     UNKNOWN_ERROR = 'unknown-error'
     FCM_ERROR_CODES = {
-        'APNS_AUTH_ERROR': 'authentication-error',
+        # FCM v1 canonical error codes
+        'NOT_FOUND': 'registration-token-not-registered',
+        'PERMISSION_DENIED': 'mismatched-credential',
+        'RESOURCE_EXHAUSTED': 'message-rate-exceeded',
+        'UNAUTHENTICATED': 'invalid-apns-credentials',
+
+        # FCM v1 new error codes
+        'APNS_AUTH_ERROR': 'invalid-apns-credentials',
         'INTERNAL': INTERNAL_ERROR,
         'INVALID_ARGUMENT': 'invalid-argument',
         'QUOTA_EXCEEDED': 'message-rate-exceeded',
-        'SENDER_ID_MISMATCH': 'authentication-error',
+        'SENDER_ID_MISMATCH': 'mismatched-credential',
         'UNAVAILABLE': 'server-unavailable',
         'UNREGISTERED': 'registration-token-not-registered',
     }

tests/test_messaging.py

@@ -855,6 +855,26 @@ def test_send_detailed_error(self, status):
         body = {'message': messaging._MessagingService.JSON_ENCODER.default(msg)}
         assert json.loads(recorder[0].body.decode()) == body
 
+    @pytest.mark.parametrize('status', HTTP_ERRORS)
+    def test_send_canonical_error_code(self, status):
+        payload = json.dumps({
+            'error': {
+                'status': 'NOT_FOUND',
+                'message': 'test error'
+            }
+        })
+        _, recorder = self._instrument_messaging_service(status=status, payload=payload)
+        msg = messaging.Message(topic='foo')
+        with pytest.raises(messaging.ApiCallError) as excinfo:
+            messaging.send(msg)
+        assert str(excinfo.value) == 'test error'
+        assert str(excinfo.value.code) == 'registration-token-not-registered'
+        assert len(recorder) == 1
+        assert recorder[0].method == 'POST'
+        assert recorder[0].url == self._get_url('explicit-project-id')
+        body = {'message': messaging._MessagingService.JSON_ENCODER.default(msg)}
+        assert json.loads(recorder[0].body.decode()) == body
+
 
 class TestTopicManagement(object):