UnsafePromise

class Util.UnsafePromise()

This represents a Promise that has its promised return value immediately available. The immediate value is unsafe to use (safety depends on specific use cases) until this UnsafePromise becomes marked as ready.

The primary use case of this would be to synchronously return a reference to an object that needs to wait for an init(): Promise<void> function to complete.

Properties

[toStringTag]
isReady
readyPromise
unsafeValue

Methods

catch()
finally()
then()

Properties

UnsafePromise.[toStringTag]

Type: string

UnsafePromise.isReady

Type: boolean

This value becomes true once this.readyPromise resolves. If this.readyPromise rejects, this value never becomes true.

UnsafePromise.readyPromise

Type: Promise <void>

This promise resolves once this.unsafeValue is safe to access.

UnsafePromise.unsafeValue

Type: T

An unsafe synchronous reference to the value returned through this promise’s then() callback.

Methods

catch

UnsafePromise.catch([onrejected])

Arguments

onrejected (null | function()) – optional The callback to execute when the Promise is rejected.

Attaches a callback for only the rejection of the Promise.

Returns: A Promise for the completion of the callback.
Return type: Promise <T | TResult>

UnsafePromise.onrejected(reason)

Arguments

reason (any()) – None

Return type

TResult | PromiseLike <TResult>

finally

UnsafePromise.finally([onfinally])

Arguments

onfinally (null | function()) – optional The callback to execute when the Promise is settled (fulfilled or rejected).

Attaches a callback that is invoked when the Promise is settled (fulfilled or rejected). The resolved value cannot be modified from the callback.

Returns: A Promise for the completion of the callback.
Return type: Promise <T>

UnsafePromise.onfinally()

Return type: void

then

UnsafePromise.then([onfulfilled[, onrejected]])

Arguments

onfulfilled (null | function()) – optional The callback to execute when the Promise is resolved.
onrejected (null | function()) – optional The callback to execute when the Promise is rejected.

Attaches callbacks for the resolution and/or rejection of the Promise.

Returns: A Promise for the completion of which ever callback is executed.
Return type: Promise <TResult1 | TResult2>

UnsafePromise.onfulfilled(value)

Arguments

value (T()) – None

Return type

TResult1 | PromiseLike <TResult1>

Util.onrejected(reason)

Arguments

reason (any()) – None

Return type

TResult2 | PromiseLike <TResult2>