JsonableError: Rename status_code and rely more on its default.

With #5598 there will soon be an application-level error code
optionally associated with a `JsonableError`, so rename this
field to make clear that it specifically refers to an
HTTP status code.

Also take this opportunity to eliminate most of the places
that refer to it, which only do so to repeat the default value.

zerver/lib/exceptions.py

@@ -5,12 +5,12 @@ from django.core.exceptions import PermissionDenied
 
 class JsonableError(Exception):
     msg = None  # type: Text
-    status_code = None  # type: int
+    http_status_code = 400  # type: int
 
-    def __init__(self, msg, status_code=400):
+    def __init__(self, msg, http_status_code=400):
-        # type: (Text) -> None
+        # type: (Text, int) -> None
         self.msg = msg
-        self.status_code = status_code
+        self.http_status_code = http_status_code
 
     def __str__(self):
         # type: () -> str

zerver/lib/request.py

@@ -11,18 +11,16 @@ from django.utils.translation import ugettext as _
 from zerver.lib.exceptions import JsonableError
 
 class RequestVariableMissingError(JsonableError):
-    def __init__(self, var_name, status_code=400):
+    def __init__(self, var_name):
         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, status_code=400):
+    def __init__(self, var_name, bad_value):
         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 '%(var_name)s': %(value)s") %

zerver/middleware.py

@@ -286,7 +286,7 @@ class JsonErrorHandler(MiddlewareMixin):
     def process_exception(self, request, exception):
         # type: (HttpRequest, Exception) -> Optional[HttpResponse]
         if isinstance(exception, JsonableError):
-            return json_error(exception.to_json_error_msg(), status=exception.status_code)
+            return json_error(exception.to_json_error_msg(), status=exception.http_status_code)
         if request.error_format == "JSON":
             logging.error(traceback.format_exc())
             return json_error(_("Internal server error"), status=500)

zerver/views/messages.py

@@ -56,10 +56,9 @@ import six
 LARGER_THAN_MAX_MESSAGE_ID = 10000000000000000
 
 class BadNarrowOperator(JsonableError):
-    def __init__(self, desc, status_code=400):
+    def __init__(self, desc):
-        # type: (str, int) -> None
+        # type: (str) -> None
         self.desc = desc
-        self.status_code = status_code
 
     def to_json_error_msg(self):
         # type: () -> str

zerver/views/streams.py

@@ -35,10 +35,10 @@ from six.moves import urllib
 import six
 
 class PrincipalError(JsonableError):
-    def __init__(self, principal, status_code=403):
+    def __init__(self, principal):
-        # type: (Text, int) -> None
+        # type: (Text) -> None
         self.principal = principal  # type: Text
-        self.status_code = status_code  # type: int
+        self.http_status_code = 403  # type: int
 
     def to_json_error_msg(self):
         # type: () -> Text