HashMaps in Anchor

Question

Does anyone have experience using HashMaps in an Anchor project?
I have the following implementation for a struct:

#[account]
#[derive(Debug)]
pub struct Company {
    pub id: u64, // 8 bytes
    pub authority: Pubkey, // 32 bytes
    pub name: String, // 24 bytes
    pub worker_container: HashMap<u64, bool>, // 8 * 10 = 80 bytes
    pub product_container: HashMap<u64, bool>, // (8 + 1) * 50 = 450 bytes
    pub bump: u8, // 1 byte
}

I can build and deploy the struct with no errors
However, while testing on JS side I got the following error:

IdlError: Type not found: {"name":"workerContainer","type":{"defined":"HashMap<u64,bool>"}}

I don't think it's due to some serialization problems.
According to https://github.com/near/borsh-js#type-mappings Borsch can serialize HashMaps so I wonder what the error could be.

(note: I'm aware that I could use a Vec, however I want to be able to check whether a key value exists quickly so I chose to use HashMaps instead)

Answer 1

Unfortunately, unlike Borsh; Anchor does not implement a JS type for hashmaps. See https://www.anchor-lang.com/docs/javascript-anchor-types