Is it possible to have long stack traces? about promise HOT 9 OPEN

Yes, I would love to see long stack traces implemented. We can use Q as a good example of a library that already implements them. We should make them disabled by default and allow people to require('promise/lib/long-stack-traces') if they want them enabled.

from promise.

Can you help me understand this stacktrace:

 ERROR  Cannot read property 'length' of null
TypeError: Cannot read property 'length' of null
    at Promise._94 (react-native-github/node_modules/promise/lib/core.js:138:31)
    at Promise._82 (react-native-github/node_modules/promise/lib/core.js:129:8)
    at react-native-github/node_modules/promise/lib/core.js:97:24
    at flush (react-native-github/node_modules/promise/node_modules/asap/raw.js:50:29)
    at process._tickCallback (node.js:415:13)

from promise.

Apparently it's a race. After tracing back this call stack to the original source it seems that asap is calling twice (and finalizing) on the same promise. If I change a part of my code from Promise.all to a serial chain this works fine.

from promise.

Interesting. Can you share the code to reproduce this? It sounds like this might be related to #93 but I was never able to get code to reproduce that.

from promise.

let me try and boil it down to something reproducible.
Another random thought, could this be an issue with interop with a different promise library like bluebird?

from promise.

It's definitely possible. Either way I really want to get to the bottom of it. If there's a bug in asap or this lib then finding it would be a huge win.

from promise.

I've reconstructed as much as I can of what the original stack trace should look like. Unfortunately it doesn't tell me much extra:

TypeError: Cannot read property 'length' of null
    at Promise._finale (react-native-github/node_modules/promise/lib/core.js:138:31)
    at Promise._resolve (react-native-github/node_modules/promise/lib/core.js:129:8)
    at react-native-github/node_modules/promise/lib/core.js:97:24
    at flush (react-native-github/node_modules/promise/node_modules/asap/raw.js:50:29)
    at process._tickCallback (node.js:415:13)
From previous event:
    at Promise._handle (react-native-github/node_modules/promise/lib/core.js:87)

from promise.

I couldn't reproduce outside of the codebase. I'm going to have to add you to my (internal) diff and you only have to change from bluebird to promise to start reproing

from promise.

It turns out this is (as you suspected) caused by asap sometimes calling back twice and sometimes not at all. The offending issue is kriskowal/asap#55, which has now been resolved. Updating asap should be sufficient, which should happen automatically if you delete any caches and re-install.

I will release an update of promise that requires the latest version of asap though to encourage people to update faster.

from promise.