Throw error inside series callback

What version of async are you using?

2.0.0-rc.6

Which environment did the issue occur in (Node version/browser version)

v6.2.0

What did you do? Please include a minimal reproducable case illustrating issue.

I’m trying to throw an error inside the series callback, but the error gets caught for some reason.

The following works fine:

throw new Error('throw_0') // => Node stops here

async.series([

    (next) => clean(distPath, next),
    (next) => copy(routes, srcPath, distPath, opts, next),
    (next) => run(routes, srcPath, distPath, next)

], (err) => {

    throw new Error('throw_1')

})

While throwing an error inside the series callback doesn’t.

// throw new Error('throw_0')

async.series([

    (next) => clean(distPath, next),
    (next) => copy(routes, srcPath, distPath, opts, next),
    (next) => run(routes, srcPath, distPath, next)

], (err) => {

    throw new Error('throw_1') // Node stops here, but the error gets caught somehow and never shows up

})

What was the actual result?

Node continues to execute. No error visible.

What did you expect to happen?

I expect that the error gets thrown and my node app crashes because of throw_1.

[aearly]

Yeah, a promise would catch any errors in the callstack – including in the callbacks. You can defer calling the callback (e.g. setImmediate(callback, null, results)) to work around that.

[electerious]

I’ve found the problem. There’s a promise deeply hidden in the run function. Somehow—and I’ve no idea why—catches all the errors, even those thrown in the async.series callback 😕