Function serialize_hashmap_as_object 

pub fn serialize_hashmap_as_object<V, S>(
    val: &HashMap<String, V>,
    serializer: S,
) -> Result<S::Ok, S::Error>
where
    V: Serialize,
    S: Serializer,

Serializer fn that serializes HashMap as k/v object. in js it would be plain js object and not js Map.

The HashMap’s entry values should themselves impl Serialize as well.

This provides great level of flexibilty to specify a specific property of the given type and not all of the properties to be serialized as js plain object instead of js Map when wasm_bindgen convert traits are implemented for the given type by using impl_wasm_traits

Example:

#[derive(serde::Serialize, serde::Deserialize, Tsify)]
struct A {
    #[cfg_attr(
        target_family = "wasm",
        serde(serialize_with = "serialize_hashmap_as_object"),
        tsify(type = "Record<string, number>")
    )]
    field: HashMap<String, u8>,
}
#[cfg(target_family = "wasm")]
impl_all_wasm_traits!(A);

#[wasm_bindgen]
pub fn some_fn() -> A {
    let mut rust_map = HashMap::new();
    rust_map.insert("key".to_string(), 1);
    rust_map.insert("otherKey".to_string(), 2);

    // in js when some_fn() is called the result will be:
    // { field: { key: 1, otherKey: 2 } }
    A { field: rust_map }
}