Remove test.cb()

[novemberborn]

test.cb() is a legacy API. It's probably time to remove it.

Ideally we can define an experiment, say "noCb" so users can opt in to not having test.cb() available.

When enabled, it should be removed from the chain:

https://github.com/avajs/ava/blob/56338dcb77246b5eca3c01e24d1cb6d66da8f71f/lib/create-chain.js#L77:L79

https://github.com/avajs/ava/blob/56338dcb77246b5eca3c01e24d1cb6d66da8f71f/lib/create-chain.js#L88:L92

Then by the time we're shipping the next breaking version we can remove it properly, from the TypeScript definition, the chain code and the implementation.

[sindresorhus]

Before it’s removed, it’s important that we have docs in place that show common test.cb use-cases with test instead. For example, promisify, events (using p-event), streams (using async iterator or get-stream, etc.

[ash0080]

Wish to include p-event similar internal,
events test is the shortcoming of AVA

[novemberborn]

@ash0080 we'd rather people use p-event directly at this stage than add more API surface to AVA.

[alastairs]

I'm writing tests for a Pulumi application, and based on their own appears those require the callback approach. Here's a (TypeScript) sample macro I've written using the callback API:

const hasTag: CbMacro<[AzureResource, string[]], PulumiContext> = (t, resource: AzureResource, expectedTags: string[]) => {
  pulumi.all([resource.name, resource.urn, resource.tags])
    .apply(([name, urn, tags]) => {
      t.deepEqual(Object.getOwnPropertyNames(tags), expectedTags,
        `Some required tags were missing from resource ${name} (${urn})`);

      t.end();
    });
}

I'd like to move away from the callback model, but It's not immediately obvious to me how to promisify this: what are the resolve and reject scenarios? Annoyingly, while Pulumi's API is asynchronous, it is only Promise-like and doesn't actually return Promises anywhere; hence the t.end(); is required inside the lambda function to indicate the test completion.

[novemberborn]

@alastairs looks like const [name, urn tags] = await new Promise(resolve => pulumi.all([…]).apply(resolve)) to me.

[alastairs]

@novemberborn That worked a treat, thank you so much 🙏