Promisify Functions

[hipstersmoothie]

closes #232 - write now can return a promise
closes #90 - same as above and getBuffer can now be async
closes #374 - base64 can now be async
closes #308 closes #445 - Jimp.read can take all args that the constructor can. Jimp.create added for clearer syntax. No need to add promises to the jimp constructor.

[hipstersmoothie]

@oliver-moran If you just merge this one all #473 and #477 will be merged as well

[hipstersmoothie]

@oliver-moran and if this one gets merged 10 issues get closed all at once 😮

[hipstersmoothie]

I think I'm gonna change it from getBuffer(mime, 'async') to getBufferAsync(mime)

[hipstersmoothie]

@oliver-moran Just added the 'async' functions. They are tested and documented. Everythings runs fine. This should be ready to go!

[hipstersmoothie]

@edi9999 what do you think of this one? it gets makes of the requested functions promises without breaking the current api

[edi9999]

in this MR I find that the duplication in the code is not good for maintanability.

Things like Bluebird can do the automatic transformation from callback to Promises.

[hipstersmoothie]

So should I use bluebird to do this? Or you want users to do that? I think it would be better just to have it supported. The code isn’t really duplicated either. I factored out the main functionality of each function and the sync and a sync functions just call them in different ways

[hipstersmoothie]

@edi9999 Switched to an implementation that just calls the current functions and return a promise. Similar to Jimp.read. I believe we should provide this functionality and not make the user do it themselves. Since we return promises in a few other places, it makes sense to do it in the last few places we can.

[hipstersmoothie]

@edi9999 have i fixed your duplication concerns?

[edi9999]

You can even just do it like this :

const promisify = (fun, ctx, args) => {
  return new Promise((resolve, reject) => {
    args.push((err, data) => {
      err && reject(err);
      resolve(data);
    });
    fun.apply(ctx, args);
  });
};

 writeAsync(path) {
        return promisify(this.write, this, [path]);
 }

This way the "promisification code" is just in one place.

[hipstersmoothie]

@edi9999 added promisify util function

[favna]

I see this closes #445 and some talk about Jimp.create but I can't find any documentation on this new function nor (easily) find it in the code changes by the PR. Could you clarify the usage?

[hipstersmoothie]

You can just use Jimp.read to make a Jimp instance. It takes all the same args as the constructor. Jimp.create also exists but it just calls Jimp.read. I'll document it now

https://github.com/oliver-moran/jimp/blob/master/src/index.js#L810

[septs]

Request update "jimp.d.ts" file defines.

[hipstersmoothie]

@septs what updates are you requesting ?