Add 'unused' lint (#241)

* Add 'unused' lint

* Keep testdata consts

linter.json

@@ -17,6 +17,7 @@
         "unparam",
         "errcheck",
         "vet",
+        "unused",
         "gosimple"
     ]
 }

src/github.com/matrix-org/dendrite/clientapi/auth/storage/accounts/membership_table.go

@@ -51,14 +51,10 @@ const selectMembershipsByLocalpartSQL = "" +
 const deleteMembershipsByEventIDsSQL = "" +
 	"DELETE FROM account_memberships WHERE event_id = ANY($1)"
 
-const updateMembershipByEventIDSQL = "" +
-	"UPDATE account_memberships SET event_id = $2 WHERE event_id = $1"
-
 type membershipStatements struct {
 	deleteMembershipsByEventIDsStmt  *sql.Stmt
 	insertMembershipStmt             *sql.Stmt
 	selectMembershipsByLocalpartStmt *sql.Stmt
-	updateMembershipByEventIDStmt    *sql.Stmt
 }
 
 func (s *membershipStatements) prepare(db *sql.DB) (err error) {
@@ -75,9 +71,6 @@ func (s *membershipStatements) prepare(db *sql.DB) (err error) {
 	if s.selectMembershipsByLocalpartStmt, err = db.Prepare(selectMembershipsByLocalpartSQL); err != nil {
 		return
 	}
-	if s.updateMembershipByEventIDStmt, err = db.Prepare(updateMembershipByEventIDSQL); err != nil {
-		return
-	}
 	return
 }
 
@@ -120,12 +113,3 @@ func (s *membershipStatements) selectMembershipsByLocalpart(
 
 	return
 }
-
-func (s *membershipStatements) updateMembershipByEventID(
-	ctx context.Context, oldEventID string, newEventID string,
-) (err error) {
-	_, err = s.updateMembershipByEventIDStmt.ExecContext(
-		ctx, oldEventID, newEventID,
-	)
-	return
-}

src/github.com/matrix-org/dendrite/cmd/syncserver-integration-tests/testdata.go

@@ -14,7 +14,7 @@
 
 package main
 
-// nolint: varcheck, deadcode
+// nolint: varcheck, deadcode, unused
 const (
 	i0StateRoomCreate = iota
 	i1StateAliceJoin

src/github.com/matrix-org/dendrite/common/partition_offset_table.go

@@ -47,6 +47,7 @@ type PartitionOffsetStatements struct {
 // Prepare converts the raw SQL statements into prepared statements.
 // Takes a prefix to prepend to the table name used to store the partition offsets.
 // This allows multiple components to share the same database schema.
+// nolint: safesql
 func (s *PartitionOffsetStatements) Prepare(db *sql.DB, prefix string) (err error) {
 	_, err = db.Exec(strings.Replace(partitionOffsetsSchema, "${prefix}", prefix, -1))
 	if err != nil {

src/github.com/matrix-org/dendrite/publicroomsapi/storage/public_rooms_table.go

@@ -134,6 +134,7 @@ type publicRoomsStatements struct {
 	updateRoomAttributeStmts                map[string]*sql.Stmt
 }
 
+// nolint: safesql
 func (s *publicRoomsStatements) prepare(db *sql.DB) (err error) {
 	_, err = db.Exec(publicRoomsSchema)
 	if err != nil {

src/github.com/matrix-org/dendrite/roomserver/storage/event_state_keys_table.go

@@ -60,10 +60,6 @@ const bulkSelectEventStateKeyNIDSQL = "" +
 	"SELECT event_state_key, event_state_key_nid FROM roomserver_event_state_keys" +
 	" WHERE event_state_key = ANY($1)"
 
-const selectEventStateKeySQL = "" +
-	"SELECT event_state_key FROM roomserver_event_state_keys" +
-	" WHERE event_state_key_nid = $1"
-
 // Bulk lookup from numeric ID to string state key for that state key.
 // Takes an array of strings as the query parameter.
 const bulkSelectEventStateKeySQL = "" +
@@ -73,7 +69,6 @@ const bulkSelectEventStateKeySQL = "" +
 type eventStateKeyStatements struct {
 	insertEventStateKeyNIDStmt     *sql.Stmt
 	selectEventStateKeyNIDStmt     *sql.Stmt
-	selectEventStateKeyStmt        *sql.Stmt
 	bulkSelectEventStateKeyNIDStmt *sql.Stmt
 	bulkSelectEventStateKeyStmt    *sql.Stmt
 }
@@ -86,7 +81,6 @@ func (s *eventStateKeyStatements) prepare(db *sql.DB) (err error) {
 	return statementList{
 		{&s.insertEventStateKeyNIDStmt, insertEventStateKeyNIDSQL},
 		{&s.selectEventStateKeyNIDStmt, selectEventStateKeyNIDSQL},
-		{&s.selectEventStateKeyStmt, selectEventStateKeySQL},
 		{&s.bulkSelectEventStateKeyNIDStmt, bulkSelectEventStateKeyNIDSQL},
 		{&s.bulkSelectEventStateKeyStmt, bulkSelectEventStateKeySQL},
 	}.prepare(db)
@@ -133,15 +127,6 @@ func (s *eventStateKeyStatements) bulkSelectEventStateKeyNID(
 	return result, nil
 }
 
-func (s *eventStateKeyStatements) selectEventStateKey(
-	ctx context.Context, txn *sql.Tx, eventStateKeyNID types.EventStateKeyNID,
-) (string, error) {
-	var eventStateKey string
-	stmt := common.TxStmt(txn, s.selectEventStateKeyStmt)
-	err := stmt.QueryRowContext(ctx, eventStateKeyNID).Scan(&eventStateKey)
-	return eventStateKey, err
-}
-
 func (s *eventStateKeyStatements) bulkSelectEventStateKey(
 	ctx context.Context, eventStateKeyNIDs []types.EventStateKeyNID,
 ) (map[types.EventStateKeyNID]string, error) {

src/github.com/matrix-org/dendrite/roomserver/storage/prepare.go

@@ -25,6 +25,7 @@ type statementList []struct {
 }
 
 // prepare the SQL for each statement in the list and assign the result to the prepared statement.
+// nolint: safesql
 func (s statementList) prepare(db *sql.DB) (err error) {
 	for _, statement := range s {
 		if *statement.statement, err = db.Prepare(statement.sql); err != nil {