True Myth / task / fromUnsafePromise

Function: fromUnsafePromise()

fromUnsafePromise<T, E>(promise): Task<T, E>

Produce a Task<T, E> from a promise of a Result<T, E>.

WARNING

This constructor assumes you have already correctly handled the promise rejection state, presumably by mapping it into the wrapped Result. It is unsafe for this promise ever to reject! You should only ever use this with Promise<Result<T, E>> you have created yourself (including via a Task, of course).

For any other Promise<Result<T, E>>, you should first attach a catch handler which will also produce a Result<T, E>.

If you call this with an unmanaged Promise<Result<T, E>>, that is, one that has not correctly set up a catch handler, the rejection will throw an UnsafePromise error that will not be catchable by awaiting the Task or its original Promise. This can cause test instability and unpredictable behavior in your application.

Type Parameters

T

T

E

E

Parameters

promise

Promise<Result<T, E>>

The promise from which to create the Task.

Returns

Task<T, E>