Struct Promise

pub struct Promise<T: 'static + FromNapiValue> { /* private fields */ }

The JavaScript Promise object representation

This Promise<T> can be awaited in the Rust THis Promise<T> can also be passed from #[napi] fn

example:

#[napi]
pub fn await_promise_in_rust(promise: Promise<u32>) {
  let value = promise.await.unwrap();

  println!("{value}");
}

But this Promise<T> can not be pass back to JavaScript. If you want to use raw JavaScript Promise API, you can use the PromiseRaw instead.

Trait Implementations

impl<T: FromNapiValue> FromNapiValue for Promise<T>

unsafe fn from_napi_value(env: napi_env, napi_val: napi_value) -> Result<Self>

Safety

fn from_unknown(value: Unknown<'_>) -> Result<Self>

impl<T: FromNapiValue> Future for Promise<T>

type Output = Result<T, Error>

The type of value produced on completion.

fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output>

Attempts to resolve the future to a final value, registering the current task for wakeup if the value is not yet available.

impl<T: FromNapiValue> TypeName for Promise<T>

fn type_name() -> &'static str

fn value_type() -> ValueType

impl<T: FromNapiValue> ValidateNapiValue for Promise<T>

unsafe fn validate(env: napi_env, napi_val: napi_value) -> Result<napi_value>

Safety

impl<T: FromNapiValue + Send> Send for Promise<T>