Added support for progress reporting.

[ghost]

I needed to be able to report progress through promises, so I modified your library to add support for this. ~~Progress reporting is always propagated through the whole chain of promises. You can modify the progress value at any point of the chain if you intend to, for example, average the progress of two promises. For example:~~

IPromise loadAsset(string bundle, string asset)
{
    var promise = new Promise();
    LoadBundle(bundle)
    .Progress(v => promise.ReportProgress(v * 0.5f))
    .Then(b => LoadAssetFromBundle(b, asset))
    .Progress(v => promise.ReportProgress(0.5f + v * 0.5f))
    .Then(() => promise.Resolve())
    .Catch(ex => promise.Reject(ex));
    return promise;
}

loadAsset("bundle", "asset").Progress(v => Debug.Log("Progress: " + v));

[RoryDungan]

This looks like a useful feature, thanks for submitting it!

We require all new code to have comprehensive unit tests and new features to have some documentation, so won't be able to merge this until those have been added.

I've added a CONTRIBUTING.md file with some more details on what we need from pull requests, so hopefully that should be a bit more obvious in future.

[ghost]

Thank you @RoryDungan. I will work on that :) I also need to review the code because I noticed a small issue in the progress propagation. Changes coming soon.

[RoryDungan]

Cool. Just let me know when you're ready for me to have a look over it again 👍

[alonsohki]

@RoryDungan I think this is good to go 😃 Let me know if you find any issues and I will fix it.

[RoryDungan]

Looks good, just need to expand on the tests a bit - see my comments above.

[ghost]

Ready for review ✔️

[alonsohki]

Hi again. Is there anything else required to be able to merge it? It would be a shame if it gets forgotten and becomes non-mergeable :)

[RoryDungan]

Sorry, just got a bit busy with other stuff. It's merged now 😁

[alonsohki]

Thank you :)