Improve the type hints of synapse.api.errors. (#7820)

2 files changed, 74 insertions, 55 deletions

diff --git a/changelog.d/7820.misc b/changelog.d/7820.misc
new file mode 100644
index 0000000000..b77b5672e3
--- /dev/null
+++ b/changelog.d/7820.misc
@@ -0,0 +1 @@
+Add type hints to synapse.api.errors module.
diff --git a/synapse/api/errors.py b/synapse/api/errors.py
index d5d4522336..cc5edb5118 100644
--- a/synapse/api/errors.py
+++ b/synapse/api/errors.py
@@ -17,11 +17,15 @@
 """Contains exceptions and error codes."""
 import json
 import logging
+import typing
 from http import HTTPStatus
-from typing import Dict, List
+from typing import Dict, List, Optional, Union
 
 from twisted.web import http
 
+if typing.TYPE_CHECKING:
+    from synapse.types import JsonDict
+
 logger = logging.getLogger(__name__)
 
 
@@ -76,11 +80,11 @@ class CodeMessageException(RuntimeError):
     """An exception with integer code and message string attributes.
 
     Attributes:
-        code (int): HTTP error code
-        msg (str): string describing the error
+        code: HTTP error code
+        msg: string describing the error
     """
 
-    def __init__(self, code, msg):
+    def __init__(self, code: Union[int, HTTPStatus], msg: str):
         super(CodeMessageException, self).__init__("%d: %s" % (code, msg))
 
         # Some calls to this method pass instances of http.HTTPStatus for `code`.
@@ -121,16 +125,16 @@ class SynapseError(CodeMessageException):
     message (as well as an HTTP status code).
 
     Attributes:
-        errcode (str): Matrix error code e.g 'M_FORBIDDEN'
+        errcode: Matrix error code e.g 'M_FORBIDDEN'
     """
 
-    def __init__(self, code, msg, errcode=Codes.UNKNOWN):
+    def __init__(self, code: int, msg: str, errcode: str = Codes.UNKNOWN):
         """Constructs a synapse error.
 
         Args:
-            code (int): The integer error code (an HTTP response code)
-            msg (str): The human-readable error message.
-            errcode (str): The matrix error code e.g 'M_FORBIDDEN'
+            code: The integer error code (an HTTP response code)
+            msg: The human-readable error message.
+            errcode: The matrix error code e.g 'M_FORBIDDEN'
         """
         super(SynapseError, self).__init__(code, msg)
         self.errcode = errcode
@@ -143,10 +147,16 @@ class ProxiedRequestError(SynapseError):
     """An error from a general matrix endpoint, eg. from a proxied Matrix API call.
 
     Attributes:
-        errcode (str): Matrix error code e.g 'M_FORBIDDEN'
+        errcode: Matrix error code e.g 'M_FORBIDDEN'
     """
 
-    def __init__(self, code, msg, errcode=Codes.UNKNOWN, additional_fields=None):
+    def __init__(
+        self,
+        code: int,
+        msg: str,
+        errcode: str = Codes.UNKNOWN,
+        additional_fields: Optional[Dict] = None,
+    ):
         super(ProxiedRequestError, self).__init__(code, msg, errcode)
         if additional_fields is None:
             self._additional_fields = {}  # type: Dict
@@ -162,12 +172,12 @@ class ConsentNotGivenError(SynapseError):
     privacy policy.
     """
 
-    def __init__(self, msg, consent_uri):
+    def __init__(self, msg: str, consent_uri: str):
         """Constructs a ConsentNotGivenError
 
         Args:
-            msg (str): The human-readable error message
-            consent_url (str): The URL where the user can give their consent
+            msg: The human-readable error message
+            consent_url: The URL where the user can give their consent
         """
         super(ConsentNotGivenError, self).__init__(
             code=HTTPStatus.FORBIDDEN, msg=msg, errcode=Codes.CONSENT_NOT_GIVEN
@@ -183,11 +193,11 @@ class UserDeactivatedError(SynapseError):
     authenticated endpoint, but the account has been deactivated.
     """
 
-    def __init__(self, msg):
+    def __init__(self, msg: str):
         """Constructs a UserDeactivatedError
 
         Args:
-            msg (str): The human-readable error message
+            msg: The human-readable error message
         """
         super(UserDeactivatedError, self).__init__(
             code=HTTPStatus.FORBIDDEN, msg=msg, errcode=Codes.USER_DEACTIVATED
@@ -199,16 +209,16 @@ class FederationDeniedError(SynapseError):
     is not on its federation whitelist.
 
     Attributes:
-        destination (str): The destination which has been denied
+        destination: The destination which has been denied
     """
 
-    def __init__(self, destination):
+    def __init__(self, destination: Optional[str]):
         """Raised by federation client or server to indicate that we are
         are deliberately not attempting to contact a given server because it is
         not on our federation whitelist.
 
         Args:
-            destination (str): the domain in question
+            destination: the domain in question
         """
 
         self.destination = destination
@@ -226,11 +236,11 @@ class InteractiveAuthIncompleteError(Exception):
     (This indicates we should return a 401 with 'result' as the body)
 
     Attributes:
-        result (dict): the server response to the request, which should be
+        result: the server response to the request, which should be
             passed back to the client
     """
 
-    def __init__(self, result):
+    def __init__(self, result: "JsonDict"):
         super(InteractiveAuthIncompleteError, self).__init__(
             "Interactive auth not yet complete"
         )
@@ -243,7 +253,6 @@ class UnrecognizedRequestError(SynapseError):
     def __init__(self, *args, **kwargs):
         if "errcode" not in kwargs:
             kwargs["errcode"] = Codes.UNRECOGNIZED
-        message = None
         if len(args) == 0:
             message = "Unrecognized request"
         else:
@@ -254,7 +263,7 @@ class UnrecognizedRequestError(SynapseError):
 class NotFoundError(SynapseError):
     """An error indicating we can't find the thing you asked for"""
 
-    def __init__(self, msg="Not found", errcode=Codes.NOT_FOUND):
+    def __init__(self, msg: str = "Not found", errcode: str = Codes.NOT_FOUND):
         super(NotFoundError, self).__init__(404, msg, errcode=errcode)
 
 
@@ -280,21 +289,23 @@ class InvalidClientCredentialsError(SynapseError):
     M_UNKNOWN_TOKEN respectively.
     """
 
-    def __init__(self, msg, errcode):
+    def __init__(self, msg: str, errcode: str):
         super().__init__(code=401, msg=msg, errcode=errcode)
 
 
 class MissingClientTokenError(InvalidClientCredentialsError):
     """Raised when we couldn't find the access token in a request"""
 
-    def __init__(self, msg="Missing access token"):
+    def __init__(self, msg: str = "Missing access token"):
         super().__init__(msg=msg, errcode="M_MISSING_TOKEN")
 
 
 class InvalidClientTokenError(InvalidClientCredentialsError):
     """Raised when we didn't understand the access token in a request"""
 
-    def __init__(self, msg="Unrecognised access token", soft_logout=False):
+    def __init__(
+        self, msg: str = "Unrecognised access token", soft_logout: bool = False
+    ):
         super().__init__(msg=msg, errcode="M_UNKNOWN_TOKEN")
         self._soft_logout = soft_logout
 
@@ -312,11 +323,11 @@ class ResourceLimitError(SynapseError):
 
     def __init__(
         self,
-        code,
-        msg,
-        errcode=Codes.RESOURCE_LIMIT_EXCEEDED,
-        admin_contact=None,
-        limit_type=None,
+        code: int,
+        msg: str,
+        errcode: str = Codes.RESOURCE_LIMIT_EXCEEDED,
+        admin_contact: Optional[str] = None,
+        limit_type: Optional[str] = None,
     ):
         self.admin_contact = admin_contact
         self.limit_type = limit_type
@@ -364,10 +375,10 @@ class StoreError(SynapseError):
 class InvalidCaptchaError(SynapseError):
     def __init__(
         self,
-        code=400,
-        msg="Invalid captcha.",
-        error_url=None,
-        errcode=Codes.CAPTCHA_INVALID,
+        code: int = 400,
+        msg: str = "Invalid captcha.",
+        error_url: Optional[str] = None,
+        errcode: str = Codes.CAPTCHA_INVALID,
     ):
         super(InvalidCaptchaError, self).__init__(code, msg, errcode)
         self.error_url = error_url
@@ -382,10 +393,10 @@ class LimitExceededError(SynapseError):
 
     def __init__(
         self,
-        code=429,
-        msg="Too Many Requests",
-        retry_after_ms=None,
-        errcode=Codes.LIMIT_EXCEEDED,
+        code: int = 429,
+        msg: str = "Too Many Requests",
+        retry_after_ms: Optional[int] = None,
+        errcode: str = Codes.LIMIT_EXCEEDED,
     ):
         super(LimitExceededError, self).__init__(code, msg, errcode)
         self.retry_after_ms = retry_after_ms
@@ -398,10 +409,10 @@ class RoomKeysVersionError(SynapseError):
     """A client has tried to upload to a non-current version of the room_keys store
     """
 
-    def __init__(self, current_version):
+    def __init__(self, current_version: str):
         """
         Args:
-            current_version (str): the current version of the store they should have used
+            current_version: the current version of the store they should have used
         """
         super(RoomKeysVersionError, self).__init__(
             403, "Wrong room_keys version", Codes.WRONG_ROOM_KEYS_VERSION
@@ -413,7 +424,7 @@ class UnsupportedRoomVersionError(SynapseError):
     """The client's request to create a room used a room version that the server does
     not support."""
 
-    def __init__(self, msg="Homeserver does not support this room version"):
+    def __init__(self, msg: str = "Homeserver does not support this room version"):
         super(UnsupportedRoomVersionError, self).__init__(
             code=400, msg=msg, errcode=Codes.UNSUPPORTED_ROOM_VERSION,
         )
@@ -435,7 +446,7 @@ class IncompatibleRoomVersionError(SynapseError):
     failing.
     """
 
-    def __init__(self, room_version):
+    def __init__(self, room_version: str):
         super(IncompatibleRoomVersionError, self).__init__(
             code=400,
             msg="Your homeserver does not support the features required to "
@@ -455,8 +466,8 @@ class PasswordRefusedError(SynapseError):
 
     def __init__(
         self,
-        msg="This password doesn't comply with the server's policy",
-        errcode=Codes.WEAK_PASSWORD,
+        msg: str = "This password doesn't comply with the server's policy",
+        errcode: str = Codes.WEAK_PASSWORD,
     ):
         super(PasswordRefusedError, self).__init__(
             code=400, msg=msg, errcode=errcode,
@@ -481,14 +492,14 @@ class RequestSendFailed(RuntimeError):
         self.can_retry = can_retry
 
 
-def cs_error(msg, code=Codes.UNKNOWN, **kwargs):
+def cs_error(msg: str, code: str = Codes.UNKNOWN, **kwargs):
     """ Utility method for constructing an error response for client-server
     interactions.
 
     Args:
-        msg (str): The error message.
-        code (str): The error code.
-        kwargs : Additional keys to add to the response.
+        msg: The error message.
+        code: The error code.
+        kwargs: Additional keys to add to the response.
     Returns:
         A dict representing the error response JSON.
     """
@@ -510,7 +521,14 @@ class FederationError(RuntimeError):
         is wrong (e.g., it referred to an invalid event)
     """
 
-    def __init__(self, level, code, reason, affected, source=None):
+    def __init__(
+        self,
+        level: str,
+        code: int,
+        reason: str,
+        affected: str,
+        source: Optional[str] = None,
+    ):
         if level not in ["FATAL", "ERROR", "WARN"]:
             raise ValueError("Level is not valid: %s" % (level,))
         self.level = level
@@ -537,16 +555,16 @@ class HttpResponseException(CodeMessageException):
     Represents an HTTP-level failure of an outbound request
 
     Attributes:
-        response (bytes): body of response
+        response: body of response
     """
 
-    def __init__(self, code, msg, response):
+    def __init__(self, code: int, msg: str, response: bytes):
         """
 
         Args:
-            code (int): HTTP status code
-            msg (str): reason phrase from HTTP response status line
-            response (bytes): body of response
+            code: HTTP status code
+            msg: reason phrase from HTTP response status line
+            response: body of response
         """
         super(HttpResponseException, self).__init__(code, msg)
         self.response = response