oknok

Makes callbacks that log and/or call the outer callback if there's an error so that you don't have to. An abstraction of the most typical kind of error handling callback.

It creates a callback that checks for an error and if there is one, it (optionally) logs it and (optionally) passes it back to the done function. If there isn't, it calls the success handler function you've defined.

Basically, you get to skip writing

if (error) {
  log(error, error.stack);
  outerDone(error);
}
else {
  …
}

and get to just write whatever was in the else. (Obviously, don't use this if you have to handle an error in a special or different way.)

It's just a way to DRY up callbacks a bit.

Installation

npm install oknok

Usage

Instead of:

function doAThing(outerDone) {
  someAPI(aCallback);

  function aCallback(error, result, otherThing) {
    if (error) {
      log(error, error.stack);
      outerDone(error);
    }
    else {
      // Use result and otherThing in case in which someAPI call succeeded.
    }
  }

You can do:

var oknok = require('oknok');

function doAThing(outerDone) {
  someAPI(oknok({ ok: successHandler, nok: outerDone }));

  function successHandler(result, otherThing, done) {
    // Use result and otherThing in case in which someAPI call succeeded.
  }
}

Here, successHandlers doesn't worry about errors. oknok will have already handled it in a way a jillion other errors are handled: by logging it and/or passing it to done.

oknok has two commonly-used parameters, ok (OK) and nok (not OK!).

You can also specify an optional log param to make it log somewhere other than console.log. You can also pass null for log to just not log.

All are optional can be undefined or null. You really should have either a nok or a log, though, in order to avoid completely silent failures.

ok will be passed all of the non-error parameters passed to the callback as well as whatever nok you provided.

Tests

Run tests with make test.

License

The MIT License (MIT)

Copyright (c) 2016 Jim Kang

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.