added stability text-to-image job

[gjohnsx]

I added a text-to-image job using the Stability AI REST API.

I wasn't sure what to do with the image in the example job so I'm just logging the huge base64 url

If you have any other ideas for what to do with the artifacts once returned I'm all ears!

[nicktrn]

Thanks @gjohnsx, thanks for your contribution!

Think you forgot to link the issue. If you edit your post to add closes #47 or fixes #47 the issue can be automatically closed on merge. Makes things easier on our end! 🙏

Left some comments.

[nicktrn]

I think we should use io.backgroundFetch() for the reasons explained here. This can be used outside of io.runTask() so we don't create an unnecessary subtask.

[nicktrn]

This is a great example of how to correctly use cacheKeys within loops! Will be useful for people to adapt to their needs.

The only issue here is the use of forEach(). This will not work as expected, especially with real subtasks. We should probably use async iteration with for (const artifact of images.artifacts) { await ... } or alternatively await Promise.all(images.artifacts.map(..)).

[gjohnsx]

@nicktrn thank you very much for the tips and for the comments!

I changed the first io.runTask to io.backgroundFetch.
Then I changed the way we iterate through the returned artifacts and we use a custom cache key inside the loop. We are just returning a URL of the image in this example.

Take a look and let me know if that looks good.

Test payload:

{
  "width": 1024,
  "height": 1024,
  "samples": 2,
  "text_prompts": [
    {
      "text": "A lighthouse on a cliff"
    }
  ]
}

[nicktrn]

I changed the first io.runTask to io.backgroundFetch

Looks good! You can make things even simpler by removing the typecast and passing it like this:

io.backgroundFetch<GenerationResponse>(...)

We are just returning a URL of the image in this example

Sure, that's fine. My main concern was people adapting the previous example without realising they're creating (async) tasks within a forEach() loop. Appreciate the comment linking to the cache key docs.