Add support for setting HTTP status codes in JsonableError.

zerver/decorator.py

@@ -393,8 +393,9 @@ def internal_notify_view(view_func):
     return _wrapped_view_func
 
 class JsonableError(Exception):
-    def __init__(self, error):
+    def __init__(self, error, status_code=400):
         self.error = error
+        self.status_code = status_code
 
     def __str__(self):
         return self.to_json_error_msg()
@@ -403,16 +404,18 @@ class JsonableError(Exception):
         return self.error
 
 class RequestVariableMissingError(JsonableError):
-    def __init__(self, var_name):
+    def __init__(self, var_name, status_code=400):
         self.var_name = var_name
+        self.status_code = status_code
 
     def to_json_error_msg(self):
         return "Missing '%s' argument" % (self.var_name,)
 
 class RequestVariableConversionError(JsonableError):
-    def __init__(self, var_name, bad_value):
+    def __init__(self, var_name, bad_value, status_code=400):
         self.var_name = var_name
         self.bad_value = bad_value
+        self.status_code = status_code
 
     def to_json_error_msg(self):
         return "Bad value for '%s': %s" % (self.var_name, self.bad_value)

zerver/middleware.py

@@ -256,7 +256,12 @@ class LogRequests(object):
 class JsonErrorHandler(object):
     def process_exception(self, request, exception):
         if hasattr(exception, 'to_json_error_msg') and callable(exception.to_json_error_msg):
-            return json_error(exception.to_json_error_msg())
+            try:
+                status_code = exception.status_code
+            except Exception:
+                logging.warning("Jsonable exception %s missing status code!" % (exception,))
+                status_code = 400
+            return json_error(exception.to_json_error_msg(), status=status_code)
         if request.error_format == "JSON":
             logging.error(traceback.format_exc())
             return json_error("Internal server error", status=500)

zerver/views/messages.py

@@ -75,9 +75,10 @@ def get_sqlalchemy_connection():
     sa_connection.execution_options(autocommit=False)
     return sa_connection
 
-class BadNarrowOperator(Exception):
+class BadNarrowOperator(JsonableError):
-    def __init__(self, desc):
+    def __init__(self, desc, status_code=400):
         self.desc = desc
+        self.status_code = status_code
 
     def to_json_error_msg(self):
         return 'Invalid narrow operator: ' + self.desc

zerver/views/streams.py

@@ -81,8 +81,9 @@ def list_to_streams(streams_raw, user_profile, autocreate=False, invite_only=Fal
     return existing_streams, created_streams
 
 class PrincipalError(JsonableError):
-    def __init__(self, principal):
+    def __init__(self, principal, status_code=400):
         self.principal = principal
+        self.status_code = status_code
 
     def to_json_error_msg(self):
         return ("User not authorized to execute queries on behalf of '%s'"