dup-collection-id.md

Duplicate id uses in collections

Configuration

• detector id: dup-collection-id
• severity: medium

Description

Collections in NEAR SDK use function new to initialize itself.

pub fn new<S>(prefix: S) -> Self
where
    S: IntoStorageKey,

The argument prefix is an identifier for collection. Every collection should have an id different from the id of other collections.

Sample code

#[near_bindgen]
#[derive(BorshDeserialize, BorshSerialize)]
pub struct Contract {
    orders: UnorderedMap<u16, Order>,
    users: UnorderedSet<AccountId>,
}

#[near_bindgen]
impl Contract {
    #[init]
    pub fn new() -> Self {
        Self {
            orders: UnorderedMap::new(StorageKey::Orders),
            users: UnorderedSet::new(StorageKey::Orders), // Should use `StorageKey::Users` here
        }
    }
}

In this sample, orders and users share the same id, which may result in unexpected behavior.