[BUG?] Array.append different Types

Developers
1

Shouldn’t this throw an error?

Screenshot 2022-07-28 at 09.35.57
Screenshot 2022-07-28 at 09.35.572410×182 65.2 KB

I was able to deploy this to mainnet and the method didn’t even throw or smth :thinking:

2

maybe @chenyan knows why. please note that WHITELIST_CANISTER is an external canister defined like this

  let WHITELIST_CANISTER = actor "s7o6c-giaaa-aaaae-qac4a-cai" : actor { 
    getWhitelist: shared () -> async [Principal];
  };
1 Like
3

I can confirm that getWhitelist indeed returns an Array of Principals, but Env.modclubWhitelist is actually an Array of Text (AccountIdentifier = Text) …

4

The screenshot says Env.modclubWhitelist : [AccountIdentifier]

Are you sure AccountIdentifier isn’t a subtype of Principal?

5

Yes, see below :thinking:

6

These are immutable arrays so subtyping applies and both array types also have common super type ‘[Any]’, and can be appended to produce another array of that type.

I suspect that is what is happening here.

3 Likes