asyncSafeCallback

Runs a callback or a promise in a safe asynchronous block. If the callback throws or the promise rejects, the function resolves to a "safe-callback-error" typed Left instead of propagating the error. If the input produces an Either, it is kept as-is. Other resolved values are wrapped in a Right.

Interactive example

Syntax

function asyncSafeCallback<
	const GenericOutput extends unknown
>(
	maybeFunction: (() => GenericOutput) | Promise<GenericOutput>
): Promise<Extract<ComputeSafeCallbackResult<GenericOutput>, any>>;

Parameters

• maybeFunction: Callback or promise to execute safely. The result can be a direct value, an Either, or a promise of either.

Return value

A promise that resolves with these rules:

• If the input produces a Left or Right: the Either is returned as-is.
• If the input succeeds with a non-Either value: the value is wrapped in SafeCallbackSuccess.
• If the callback throws or the promise rejects: SafeCallbackError (left("safe-callback-error", error)) is resolved.

See also

• safeCallback – Version that keeps a synchronous output when possible.
• left – Build a typed Left.