Call a function and return a fallback value or undefined if it throws.
Cuts out the performance overhead of creating a stack trace, for cases where it won't be used anyway.
import { catcher, catchWrap } from '@isaacs/catcher'
import { functionThatMightThrow } from 'some-module'
const resultOrUndefined = catcher(functionThatMightThrow)
const resultOr99 = catcher(functionThatMightThrow, 99)
const functionThatDoesNotThrow = catchWrap(functionThatMightThrow)
// this returns undefined rather than throwing
const resultOrUndefined = functionThatDoesNotThrow(123)
const return99onFailure = catchWrap(functionThatMightThrow, 99)
const resultOr99 = return99onFailure(234)Properly supports types for the returned function if the function
being wrapped has up to 10 overload signatures, adding the type
of the caughtValue (or undefined if not provided) to the return
type of each signature. For example:
function x(): boolean
function x(s: string): string
function x(s?: string) {
if (typeof s === 'undefined') return true
else if (typeof s === 'string') return s
else throw new Error('not a string or undefined')
}
const wrapped = catchWrap(x, 99)
const b = wrapped()
// ^? - boolean | 99
const z = wrapped('y')
// ^? - string | 99See the typedocs for detailed API info.
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