Add additional type hints to the storage.

mypy.ini

@@ -80,7 +80,11 @@ files =
   synapse/storage/database.py,
   synapse/storage/engines,
   synapse/storage/persist_events.py,
+  synapse/storage/push_rule.py,
+  synapse/storage/relations.py,
+  synapse/storage/roommember.py,
   synapse/storage/state.py,
+  synapse/storage/types.py,
   synapse/storage/util,
   synapse/streams,
   synapse/types.py,

synapse/storage/relations.py

@@ -14,10 +14,12 @@
 # limitations under the License.
 
 import logging
+from typing import Any, Dict, List, Optional, Tuple
 
 import attr
 
 from synapse.api.errors import SynapseError
+from synapse.types import JsonDict
 
 logger = logging.getLogger(__name__)
 
@@ -27,18 +29,18 @@ class PaginationChunk:
     """Returned by relation pagination APIs.
 
     Attributes:
-        chunk (list): The rows returned by pagination
-        next_batch (Any|None): Token to fetch next set of results with, if
+        chunk: The rows returned by pagination
+        next_batch: Token to fetch next set of results with, if
             None then there are no more results.
-        prev_batch (Any|None): Token to fetch previous set of results with, if
+        prev_batch: Token to fetch previous set of results with, if
             None then there are no previous results.
     """
 
-    chunk = attr.ib()
-    next_batch = attr.ib(default=None)
-    prev_batch = attr.ib(default=None)
+    chunk = attr.ib(type=List[JsonDict])
+    next_batch = attr.ib(type=Optional[Any], default=None)
+    prev_batch = attr.ib(type=Optional[Any], default=None)
 
-    def to_dict(self):
+    def to_dict(self) -> Dict[str, Any]:
         d = {"chunk": self.chunk}
 
         if self.next_batch:
@@ -59,25 +61,25 @@ class RelationPaginationToken:
     boundaries of the chunk as pagination tokens.
 
     Attributes:
-        topological (int): The topological ordering of the boundary event
-        stream (int): The stream ordering of the boundary event.
+        topological: The topological ordering of the boundary event
+        stream: The stream ordering of the boundary event.
     """
 
-    topological = attr.ib()
-    stream = attr.ib()
+    topological = attr.ib(type=int)
+    stream = attr.ib(type=int)
 
     @staticmethod
-    def from_string(string):
+    def from_string(string: str) -> "RelationPaginationToken":
         try:
             t, s = string.split("-")
             return RelationPaginationToken(int(t), int(s))
         except ValueError:
             raise SynapseError(400, "Invalid token")
 
-    def to_string(self):
+    def to_string(self) -> str:
         return "%d-%d" % (self.topological, self.stream)
 
-    def as_tuple(self):
+    def as_tuple(self) -> Tuple[Any, ...]:
         return attr.astuple(self)
 
 
@@ -89,23 +91,23 @@ class AggregationPaginationToken:
     aggregation groups, we can just use them as our pagination token.
 
     Attributes:
-        count (int): The count of relations in the boundar group.
-        stream (int): The MAX stream ordering in the boundary group.
+        count: The count of relations in the boundar group.
+        stream: The MAX stream ordering in the boundary group.
     """
 
-    count = attr.ib()
-    stream = attr.ib()
+    count = attr.ib(type=int)
+    stream = attr.ib(type=int)
 
     @staticmethod
-    def from_string(string):
+    def from_string(string: str) -> "AggregationPaginationToken":
         try:
             c, s = string.split("-")
             return AggregationPaginationToken(int(c), int(s))
         except ValueError:
             raise SynapseError(400, "Invalid token")
 
-    def to_string(self):
+    def to_string(self) -> str:
         return "%d-%d" % (self.count, self.stream)
 
-    def as_tuple(self):
+    def as_tuple(self) -> Tuple[Any, ...]:
         return attr.astuple(self)