isResultErr

Returns true for failed Result tuple

Usage

Check if a value is both a Result tuple and an Err result.

import * as _ from 'radashi'

declare const value: unknown

if (_.isResultErr(value)) {
  value // <-- now an Err<Error> type
  value[0] // <-- This is the error!
}

Also see the related isResult and isResultOk functions.