A second batch of Pydantic models for rest/client/account.py (#13687)

1 files changed, 17 insertions, 2 deletions

diff --git a/synapse/http/servlet.py b/synapse/http/servlet.py

index 26aaabfb34..80acbdcf3c 100644
--- a/synapse/http/servlet.py
+++ b/synapse/http/servlet.py
@@ -28,7 +28,8 @@ from typing import (
     overload,
 )
 
-from pydantic import BaseModel, ValidationError
+from pydantic import BaseModel, MissingError, PydanticValueError, ValidationError
+from pydantic.error_wrappers import ErrorWrapper
 from typing_extensions import Literal
 
 from twisted.web.server import Request
@@ -714,7 +715,21 @@ def parse_and_validate_json_object_from_request(
     try:
         instance = model_type.parse_obj(content)
     except ValidationError as e:
-        raise SynapseError(HTTPStatus.BAD_REQUEST, str(e), errcode=Codes.BAD_JSON)
+        # Choose a matrix error code. The catch-all is BAD_JSON, but we try to find a
+        # more specific error if possible (which occasionally helps us to be spec-
+        # compliant) This is a bit awkward because the spec's error codes aren't very
+        # clear-cut: BAD_JSON arguably overlaps with MISSING_PARAM and INVALID_PARAM.
+        errcode = Codes.BAD_JSON
+
+        raw_errors = e.raw_errors
+        if len(raw_errors) == 1 and isinstance(raw_errors[0], ErrorWrapper):
+            raw_error = raw_errors[0].exc
+            if isinstance(raw_error, MissingError):
+                errcode = Codes.MISSING_PARAM
+            elif isinstance(raw_error, PydanticValueError):
+                errcode = Codes.INVALID_PARAM
+
+        raise SynapseError(HTTPStatus.BAD_REQUEST, str(e), errcode=errcode)
 
     return instance