feat: Add must_use to update_user functions

autopush-common/src/db/bigtable/bigtable_client/mod.rs

@@ -504,6 +504,7 @@ impl DbClient for BigTableClientImpl {
     /// BigTable doesn't really have the concept of an "update". You simply write the data and
     /// the individual cells create a new version. Depending on the garbage collection rules for
     /// the family, these can either persist or be automatically deleted.
+    #[must_use]
     async fn update_user(&self, user: &User) -> DbResult<bool> {
         self.add_user(user).await?;
         // TODO: is a conditional check possible?

autopush-common/src/db/dual/mod.rs

@@ -120,6 +120,7 @@ impl DbClient for DualClientImpl {
         target.add_user(user).await
     }
 
+    #[must_use]
     async fn update_user(&self, user: &User) -> DbResult<bool> {
         //  If the UAID is in the allowance, move them to the new data store
         let (target, is_primary) = self.allot(&user.uaid).await?;

autopush-common/src/db/dynamodb/mod.rs

@@ -158,6 +158,7 @@ impl DbClient for DdbClientImpl {
         Ok(())
     }
 
+    #[must_use]
     async fn update_user(&self, user: &User) -> DbResult<bool> {
         let mut user_map = serde_dynamodb::to_hashmap(&user)?;
         user_map.remove("uaid");

autopush-common/src/db/mock.rs

@@ -20,6 +20,7 @@ impl DbClient for Arc<MockDbClient> {
         Arc::as_ref(self).add_user(user).await
     }
 
+    #[must_use]
     async fn update_user(&self, user: &User) -> DbResult<bool> {
         Arc::as_ref(self).update_user(user).await
     }