rmdm / timeoutable-wrapper

Timeoutable

timeoutable-wrapper

A wrapper for a potentially long-running task to signal it's timed out. Does not halt the wrapped task, only signals it's timed out (it's your business how to react on the timeout) by throwing TimeoutError. Supports both promises and node-style callbacks.

Install

    npm i --save timeoutable-wrapper

Usage

const timeoutable = require('timeoutable-wrapper')

const potentiallyLongRunningTask = async function (arg1, arg2) {
    /* some long-running code */
    return result
}

// or, with callback
const anotherPotentiallyLongRunningTask = function (arg1, arg2, cb) {
    /* some long-running code */
    cb(null, result)
}

const timeoutableTask = timeoutable(potentiallyLongRunningTask, 5000)
const anotherTimeoutableTask = timeoutable(anotherPotentiallyLongRunningTask, 5000)

try {

    // if task is not completed within 5000 msecs - throw TimeoutError
    const result = await timeoutableTask(arg1, arg2)

    // if another task is not called callback within 5000 msecs - throw TimeoutError
    const result2 = await anotherTimeoutableTask(arg1, arg2)

} catch (err) {
    if (err.name === 'TimeoutError') { // or err instanceof timeoutable.TimeoutError
        // it's timeout
    } else {
        // it's something else
    }
}

API

timeoutable (fn, ms) -> Function

Wraps passed function and returns another one, which throws TimeoutError when specified ms expired before fn returned result.

timeoutable.using(PromiseLib) -> timeoutable

Returns an instance of timeoutable-wrapper that uses specified PromiseLib to construct and return promises from the lib.

timeoutable.TimeoutError

Type for errors thrown on expired timeouts.