Promises and node v0.12

[mainakae]

Hello all,

I've noticed that after upgrading my node, form 0.10.x to 0.12.2, I'm no longer able to call the "finally" method on promises returned by the api; now it throws "TypeError: undefined is not a function".

var db = new PouchDB('http:https://localhost:5984/db");

db.allDocs().then(...).finally(...); // NO LONGER WORKING!

[daleharvey]

Hrm I dont think Promise.finally is in the official spec? if so it shouldnt have ever been part of our API apologies

[calvinmetcalf]

right and you were never able to do this in the browser, it's because we
only use bluebird for promises if native ones are not available

On Wed, May 13, 2015 at 8:37 AM Dale Harvey [email protected]
wrote:

Hrm I dont think Promise.finally is in the official spec? if so it
shouldnt have ever been part of our API apologies

—
Reply to this email directly or view it on GitHub
#3839 (comment).

[daleharvey]

We should either 1. Figure out how to remove finally from bluebird promises, 2. Use a spec compliant lib, 3. Only use native promises (not support older node versions)

It looks like all stable releases of node support Promises natively but not sure what the uptake for these releases are, may be harsh to drop support already

[calvinmetcalf]

you can just switch to using lie only and not bluebird

On Wed, May 13, 2015 at 9:44 AM Dale Harvey [email protected]
wrote:

We should either 1. Figure out how to remove finally from bluebird
promises, 2. Use a spec compliant lib, 3. Not support node versions that
dont support native promises.

It looks like all stable releases of node support Promises natively but
not sure what the uptake for these releases are, may be harsh to drop
support already

—
Reply to this email directly or view it on GitHub
#3839 (comment).

[mainakae]

I know it's not part of the specification, I've been trying out lately lie, q and bluebird among others, and though it's somehow arguable and prone to change in the future, seems that bluebird is the right choice. In fact I adopted it as the promises library for my latest app (in part in sake of homogeneity with PouchDB).

The issue is not so much about loosing that functionality (again: as things go by, you might be inclined to chose another lib, and then following tightly the specification will be a bonus) but about some shaky things going on under the hood, maybe worth checking.

[daleharvey]

In node 0.12 Promises are natively supported, so it will start to use the native promises which dont have .finally, similiar to what happens in the browser. We have always planned to be spec compatible so we can remove any of our own Promises code when its widely enough supported.

Removing bluebird and just using lie for older node versions sounds like a good plan

[nolanlawson]

I'm fine with removing bluebird and using global.Promise || require('lie'). Simplifies things a lot, although technically may justify a major version release.

[daleharvey]

Fixed in 09ce6c8