Fix some lies, and other clarifications, in docstrings

The documentation on get_json has been wrong ever since the very first commit
to synapse...

contrib/cmdclient/http.py

@@ -36,15 +36,13 @@ class HttpClient(object):
                 the request body. This will be encoded as JSON.
 
         Returns:
-            Deferred: Succeeds when we get *any* HTTP response.
+            Deferred: Succeeds when we get a 2xx HTTP response. The result
-
+            will be the decoded JSON body.
-            The result of the deferred is a tuple of `(code, response)`,
-            where `response` is a dict representing the decoded JSON body.
         """
         pass
 
     def get_json(self, url, args=None):
-        """ Get's some json from the given host homeserver and path
+        """ Gets some json from the given host homeserver and path
 
         Args:
             url (str): The URL to GET data from.
@@ -54,10 +52,8 @@ class HttpClient(object):
                 and *not* a string.
 
         Returns:
-            Deferred: Succeeds when we get *any* HTTP response.
+            Deferred: Succeeds when we get a 2xx HTTP response. The result
-
+            will be the decoded JSON body.
-            The result of the deferred is a tuple of `(code, response)`,
-            where `response` is a dict representing the decoded JSON body.
         """
         pass
 

synapse/federation/federation_client.py

@@ -474,8 +474,13 @@ class FederationClient(FederationBase):
             content (object): Any additional data to put into the content field
                 of the event.
         Return:
-            A tuple of (origin (str), event (object)) where origin is the remote
+            Deferred: resolves to a tuple of (origin (str), event (object))
-            homeserver which generated the event.
+            where origin is the remote homeserver which generated the event.
+
+            Fails with a ``CodeMessageException`` if the chosen remote server
+            returns a 300/400 code.
+
+            Fails with a ``RuntimeError`` if no servers were reachable.
         """
         valid_memberships = {Membership.JOIN, Membership.LEAVE}
         if membership not in valid_memberships:
@@ -528,6 +533,27 @@ class FederationClient(FederationBase):
 
     @defer.inlineCallbacks
     def send_join(self, destinations, pdu):
+        """Sends a join event to one of a list of homeservers.
+
+        Doing so will cause the remote server to add the event to the graph,
+        and send the event out to the rest of the federation.
+
+        Args:
+            destinations (str): Candidate homeservers which are probably
+                participating in the room.
+            pdu (BaseEvent): event to be sent
+
+        Return:
+            Deferred: resolves to a dict with members ``origin`` (a string
+            giving the serer the event was sent to, ``state`` (?) and
+            ``auth_chain``.
+
+            Fails with a ``CodeMessageException`` if the chosen remote server
+            returns a 300/400 code.
+
+            Fails with a ``RuntimeError`` if no servers were reachable.
+        """
+
         for destination in destinations:
             if destination == self.server_name:
                 continue
@@ -635,6 +661,26 @@ class FederationClient(FederationBase):
 
     @defer.inlineCallbacks
     def send_leave(self, destinations, pdu):
+        """Sends a leave event to one of a list of homeservers.
+
+        Doing so will cause the remote server to add the event to the graph,
+        and send the event out to the rest of the federation.
+
+        This is mostly useful to reject received invites.
+
+        Args:
+            destinations (str): Candidate homeservers which are probably
+                participating in the room.
+            pdu (BaseEvent): event to be sent
+
+        Return:
+            Deferred: resolves to None.
+
+            Fails with a ``CodeMessageException`` if the chosen remote server
+            returns a non-200 code.
+
+            Fails with a ``RuntimeError`` if no servers were reachable.
+        """
         for destination in destinations:
             if destination == self.server_name:
                 continue

synapse/federation/transport/client.py

@@ -193,6 +193,26 @@ class TransportLayerClient(object):
     @defer.inlineCallbacks
     @log_function
     def make_membership_event(self, destination, room_id, user_id, membership):
+        """Asks a remote server to build and sign us a membership event
+
+        Note that this does not append any events to any graphs.
+
+        Args:
+            destination (str): address of remote homeserver
+            room_id (str): room to join/leave
+            user_id (str): user to be joined/left
+            membership (str): one of join/leave
+
+        Returns:
+            Deferred: Succeeds when we get a 2xx HTTP response. The result
+            will be the decoded JSON body (ie, the new event).
+
+            Fails with ``HTTPRequestException`` if we get an HTTP response
+            code >= 300.
+
+            Fails with ``NotRetryingDestination`` if we are not yet ready
+            to retry this server.
+        """
         valid_memberships = {Membership.JOIN, Membership.LEAVE}
         if membership not in valid_memberships:
             raise RuntimeError(

synapse/http/matrixfederationclient.py

@@ -125,6 +125,8 @@ class MatrixFederationHttpClient(object):
                 code >= 300.
             Fails with ``NotRetryingDestination`` if we are not yet ready
                 to retry this server.
+            (May also fail with plenty of other Exceptions for things like DNS
+                failures, connection failures, SSL failures.)
         """
         limiter = yield synapse.util.retryutils.get_retry_limiter(
             destination,
@@ -302,8 +304,10 @@ class MatrixFederationHttpClient(object):
 
         Returns:
             Deferred: Succeeds when we get a 2xx HTTP response. The result
-            will be the decoded JSON body. On a 4xx or 5xx error response a
+            will be the decoded JSON body.
-            CodeMessageException is raised.
+
+            Fails with ``HTTPRequestException`` if we get an HTTP response
+            code >= 300.
 
             Fails with ``NotRetryingDestination`` if we are not yet ready
             to retry this server.
@@ -360,8 +364,10 @@ class MatrixFederationHttpClient(object):
                 try the request anyway.
         Returns:
             Deferred: Succeeds when we get a 2xx HTTP response. The result
-            will be the decoded JSON body. On a 4xx or 5xx error response a
+            will be the decoded JSON body.
-            CodeMessageException is raised.
+
+            Fails with ``HTTPRequestException`` if we get an HTTP response
+            code >= 300.
 
             Fails with ``NotRetryingDestination`` if we are not yet ready
             to retry this server.
@@ -410,10 +416,11 @@ class MatrixFederationHttpClient(object):
             ignore_backoff (bool): true to ignore the historical backoff data
                 and try the request anyway.
         Returns:
-            Deferred: Succeeds when we get *any* HTTP response.
+            Deferred: Succeeds when we get a 2xx HTTP response. The result
+            will be the decoded JSON body.
 
-            The result of the deferred is a tuple of `(code, response)`,
+            Fails with ``HTTPRequestException`` if we get an HTTP response
-            where `response` is a dict representing the decoded JSON body.
+            code >= 300.
 
             Fails with ``NotRetryingDestination`` if we are not yet ready
             to retry this server.