Morph on failure

I have a type

const T = type({ id: "string>0", label: "string>0" })

const T = type({ id: "string>0", label: "string>0" })

and objects of type { id: string>0, label?: string>=0 } and want to create a type that will try to morph with (o: { id: string>0, label?: string>=0 }) => { o.label ||= o.id } only on failure, and then try to revalidate with the same validator What's the best way to do that?

2 Replies

DimavaOP•3mo ago

I guess I need an ordered union for this My current solution

export function migrate<const def>(
  def: type.validate<def>,
  ...migrations: type.Any[]
) {
  const T = type(def) as type.Any
  return type('unknown.any')
    .pipe((v, _ctx) => {
      let result = T(v)
      if (!(result instanceof type.errors))
        return result
      for (const migration of migrations) {
        const migResult = migration(result)
        if (!(migResult instanceof type.errors)) {
          result = migResult
        }
      }
      return T(result)
    })
}

export function migrate<const def>(
  def: type.validate<def>,
  ...migrations: type.Any[]
) {
  const T = type(def) as type.Any
  return type('unknown.any')
    .pipe((v, _ctx) => {
      let result = T(v)
      if (!(result instanceof type.errors))
        return result
      for (const migration of migrations) {
        const migResult = migration(result)
        if (!(migResult instanceof type.errors)) {
          result = migResult
        }
      }
      return T(result)
    })
}

ssalbdivad•3mo ago

Ordered unions are a thing but not something I've exposed yet in the primary API I'm going to use them for match expressions though since that's essentially what pattern matching is

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Morph on failure