mask() is not recursive

https://codesandbox.io/s/superstruct-ff5i4-forked-ye1ns?file=/src/index.js

Notice that zzz is silently removed (expected), but unk is not (surprising).

import { type, mask, number } from "superstruct";

let data = {
  id: 1,
  zzz: 444,
  some: {
    a: 10,
    unk: 55
  }
};

let Type = type({
  id: number(),
  some: type({
    a: number()
  })
});

console.log(JSON.stringify(mask(data, Type)));

// {"id":1,"some":{"a":10,"unk":55}} 

P.S. I don’t want to wrap all the type() I have in the code with masked(), because it produces a lot of boilerplate. I assume that the decision of stripping unknown properties is to be made at the caller side (which is likely singular) and not at the definition side (which has way higher cardinality).

[dko-slapdash]

Oh yeah, that’s right! So for assert/is, coerce is definitely always = false then.

[dko-slapdash]

I think it would involve not implementing mask with masked under the covers. Instead, mask: true would be an option pass in to validate and run (which the mask function would pass). And the masking logic would be handled inside the run function. This would allow it to be recursive.

Here is the PR following the above idea: https://github.com/ianstormtaylor/superstruct/pull/629