Bugbear: Add Mutable Parameter fixes (#9682)

Part of #9366

Adds in fixes for B006 and B008, both relating to mutable parameter lint errors.

Signed-off-by: Jonathan de Jong <jonathan@automatia.nl>

1 files changed, 14 insertions, 6 deletions

diff --git a/synapse/storage/database.py b/synapse/storage/database.py
index b302cd5786..fa15b0ce5b 100644
--- a/synapse/storage/database.py
+++ b/synapse/storage/database.py
@@ -900,7 +900,7 @@ class DatabasePool:
         table: str,
         keyvalues: Dict[str, Any],
         values: Dict[str, Any],
-        insertion_values: Dict[str, Any] = {},
+        insertion_values: Optional[Dict[str, Any]] = None,
         desc: str = "simple_upsert",
         lock: bool = True,
     ) -> Optional[bool]:
@@ -927,6 +927,8 @@ class DatabasePool:
             Native upserts always return None. Emulated upserts return True if a
             new entry was created, False if an existing one was updated.
         """
+        insertion_values = insertion_values or {}
+
         attempts = 0
         while True:
             try:
@@ -964,7 +966,7 @@ class DatabasePool:
         table: str,
         keyvalues: Dict[str, Any],
         values: Dict[str, Any],
-        insertion_values: Dict[str, Any] = {},
+        insertion_values: Optional[Dict[str, Any]] = None,
         lock: bool = True,
     ) -> Optional[bool]:
         """
@@ -982,6 +984,8 @@ class DatabasePool:
             Native upserts always return None. Emulated upserts return True if a
             new entry was created, False if an existing one was updated.
         """
+        insertion_values = insertion_values or {}
+
         if self.engine.can_native_upsert and table not in self._unsafe_to_upsert_tables:
             self.simple_upsert_txn_native_upsert(
                 txn, table, keyvalues, values, insertion_values=insertion_values
@@ -1003,7 +1007,7 @@ class DatabasePool:
         table: str,
         keyvalues: Dict[str, Any],
         values: Dict[str, Any],
-        insertion_values: Dict[str, Any] = {},
+        insertion_values: Optional[Dict[str, Any]] = None,
         lock: bool = True,
     ) -> bool:
         """
@@ -1017,6 +1021,8 @@ class DatabasePool:
             Returns True if a new entry was created, False if an existing
             one was updated.
         """
+        insertion_values = insertion_values or {}
+
         # We need to lock the table :(, unless we're *really* careful
         if lock:
             self.engine.lock_table(txn, table)
@@ -1077,7 +1083,7 @@ class DatabasePool:
         table: str,
         keyvalues: Dict[str, Any],
         values: Dict[str, Any],
-        insertion_values: Dict[str, Any] = {},
+        insertion_values: Optional[Dict[str, Any]] = None,
     ) -> None:
         """
         Use the native UPSERT functionality in recent PostgreSQL versions.
@@ -1090,7 +1096,7 @@ class DatabasePool:
         """
         allvalues = {}  # type: Dict[str, Any]
         allvalues.update(keyvalues)
-        allvalues.update(insertion_values)
+        allvalues.update(insertion_values or {})
 
         if not values:
             latter = "NOTHING"
@@ -1513,7 +1519,7 @@ class DatabasePool:
         column: str,
         iterable: Iterable[Any],
         retcols: Iterable[str],
-        keyvalues: Dict[str, Any] = {},
+        keyvalues: Optional[Dict[str, Any]] = None,
         desc: str = "simple_select_many_batch",
         batch_size: int = 100,
     ) -> List[Any]:
@@ -1531,6 +1537,8 @@ class DatabasePool:
             desc: description of the transaction, for logging and metrics
             batch_size: the number of rows for each select query
         """
+        keyvalues = keyvalues or {}
+
         results = []  # type: List[Dict[str, Any]]
 
         if not iterable: