Argument Validation Primitives

[pzuraq]

Big thanks to @snewcomer and @rwjblue for helping with the initial design!

Rendered

[snewcomer]

This is a wonderful, well written RFC. Surely seems like the right direction.

[snewcomer]

it will not be consumed by the external tracking contexts

How is this guaranteed?

[pzuraq]

We have the ability to disable autotracking contexts internally, and use it for various reasons (such as backwards compatibility). We have not exposed this capability, and generally don't think we will do so as in most cases it doesn't make sense, but I think here since this is a DEBUG only feature it may make sense. It does mean that validations may not rerun when you think they would, but it also prevents behavior from diverging too much in production.

[snewcomer]

I really like this. Similar to composing validations on changesets.

[wagenet]

Is there still interest in moving this forward?

[kategengler]

We're putting this into FCP to close -- the way we write components has evolved a lot since this was proposed.

[NullVoxPopuli]

Example of using a default value in gjs:

function defaultFoo(x) {
  return x ?? 'default value';
}

<template>
  {{defaultFoo @foo}}
</template>

and with typescript:

function defaultFoo(x: string | undefined) {
  return x ?? 'default value';
}

<template>
  {{defaultFoo @foo}}
</template> satisfies TOC<{
  Args: {
    foo?: string;
  }
}>