types for defining JSON schemas

schema.ts

type Required<T> = {
  [K in keyof T]: Schema<T>
}

interface ObjectSchema<T> {
  type: 'object'
  required: Array<keyof T>
  properties: Required<T>
}

interface ArraySchema<T> {
  type: 'array'
  items: ObjectSchema<T>
}

type Primitive
  = 'string'
  | 'number'
  | 'boolean'
  | 'null'

type PrimitiveSchema
  = { type: Primitive }
  | { type: Array<Primitive>}

type Schema<T>
  = ObjectSchema<T>
  | ArraySchema<T>
  | PrimitiveSchema