Code generation that deduplicates validation logic

[ggoodman]

Use-case

Imagine you're building validator codecs for a set of inter-related schemas that define $refs on each other. The (awesome) code generation results in these being treated as totally isolated IIFE-enclosed validators. These validators duplicate the validation logic of all referenced schemas.

Request

It would be really interesting to have a facility whereby a set of inter-related schemas could be compiled as a unit and thereby produced smaller validation logic by referencing each other appropriately. I suspect that this would require major changes to how errors are collected as we would now have N validator functions instead of 1 on which errors may be added.

Anyway, schemasafe is a fantastic bit of work. Really appreciate the rigour, speed and comprehensiveness. I'm using it with https://github.com/ggoodman/json-schema-to-dts to build codegen typed validation codecs.

[ChALkeR]

Ah, disregard the previous comment, I misunderstood.

Sorry for the late reply on this.

Compiling several schemas into one object to avoid duplication is an interesting request, this should definitely be viable.
Will require some some API changes though, I will need to think about this.

[ChALkeR]

With e931d97 in place, chalker/multi-schema branch implements this as a proof-of-concept (not cleaned up)

The API will likely be different though
Also, untested yet
Also, doesn't yet automatically add everything to schemas object. Fixed

This seems to work though:

const schemas = {
  "a": {
    "type": "object",
    "properties": {
      "value": { "$ref": "b" }
    }
  },
  "b": {
    "type": "array",
    "items": { "$ref": "a" }
  }
}
const validates = validators(Object.values(schemas), { schemas })
console.log(validates[1]([]))
console.log(validates.toModule())

This also works:

const schemas = [
  {
    $id: "https://example.com/a",
    "type": "object",
    "properties": {
      "value": { "$ref": "https://example.com/b" }
    }
  },
  {
    $id: "https://example.com/b",
    "type": "array",
    "items": { "$ref": "https://example.com/a" }
  }
]
const validates = validators(schemas, { schemas })
console.log(validates[1]([]))
console.log(validates.toModule())

[ChALkeR]

This also works now:

const schemas = [
  {
    $id: "https://example.com/a",
    "type": "object",
    "properties": {
      "value": { "$ref": "https://example.com/b" }
    }
  },
  {
    $id: "https://example.com/b",
    "type": "array",
    "items": { "$ref": "https://example.com/a" }
  },
  {}
]
const validates = validators(schemas)
console.log(validates[1]([]))
console.log(validates.toModule())

The API will likely change though.

[ChALkeR]

The API has changed to validate(schemas, { multi: true }) instead of validators(schemas).
That'll likely be the one that will get landed.

[ChALkeR]

Implemented in 1272774, now both parser() and validator() have a new { multi: true } option that allows compiling an array of schemas at once to a single module.

See example in tests.

Not properly documented for now.

[ChALkeR]

Released in v1.0.0-rc.9