promise-catch-listener

Install

npm install --save promise-catch-listener

Usage

var onError = require('promise-catch-listener')({
    chalk: require('chalk')
});

new Promise(function(reject, resolve){
    throw new Error('a funky error');
})
.catch(onError('A value to resolve to after error.'))
.then(console.log.bind(console));

Output from the above code should look something like this:

Error a funky error {
 1 line# 6 col# 11 in /path/to/my/program.js -- <unknown>
 2 line# 5 col# 5 in /path/to/my/program.js -- Object.<anonymous>
 3 line# 428 col# 26 in module.js -- Module._compile
 4 line# 446 col# 10 in module.js -- Object.Module._extensions..js
 5 line# 353 col# 32 in module.js -- Module.load
 6 line# 308 col# 12 in module.js -- Function.Module._load
 7 line# 469 col# 10 in module.js -- Function.Module.runMain
 8 line# 124 col# 18 in node.js -- startup
 9 line# 882 col# 3 in node.js -- <unknown>
}
A value to resolve to after error.

API

var onErrorFactory = require('promise-catch-listener');

onErrorFactory(options) -> onError

Returns an error handler factory.

options.on

Turn on, or off all error tracking using boolean true, or false.

options.rethrow

Throw all errors instead of just printing.

If options.rethrow is false the error doesn't stop the execution.

options.showStack

Print a stack trace if set to true. Print a regular error if options.showStack is set to false.

options.chalk

Give all error handlers the chalk module to enable nicely colored error logs. options.chalk applies to all errors.

chalk is not included by default because this lib might be used in other environments where chalk isn't needed.

var onError = require('promise-catch-listener')({
    chalk: require('chalk') //Passing in chalk for colors.
});

onError(returnValue, options) -> callback

Returns an error handler to be passed to promise.catch.

returnValue is the value you want returned from the the catch handler. This value will be resolved in the next then callback of the promise chain.

returnValue should be a javascript value, or a callback function. If you pass a callback the return of that callback will be the return value of the catch handler.

The options for onError are the same as the options for onErrorFactory except there is no chalk option.

These options only work for the current promise.catch.

options.on

If true the error will caught, and be printed from the current promise.

options.rethrow

If true the error will be thrown again from the current promise.

options.showStack

If true a stack trace will be printed from the current promise. If false a simple error notification will be printed.

About

I'm always adding a callback to promise.catch just to print an error, or prevent an error from stopping the process. I'm getting a little tired of doing that so I thought a module would be a good idea. I also added some extra functionality I thought would be good for more control.