componentProps.ts

import { Data } from './common'

export type ComponentPropsOptions<P = Data> =
  | ComponentObjectPropsOptions<P>
  | string[]

export type ComponentObjectPropsOptions<P = Data> = {
  [K in keyof P]: Prop<P[K]> | null
}

export type Prop<T, D = T> = PropOptions<T, D> | PropType<T>

type DefaultFactory<T> = () => T | null | undefined

export interface PropOptions<T = any, D = T> {
  type?: PropType<T> | true | null
  required?: boolean
  default?: D | DefaultFactory<D> | null | undefined | object
  validator?(value: unknown): boolean
}

export type PropType<T> = PropConstructor<T> | PropConstructor<T>[]

type PropConstructor<T> =
  | { new (...args: any[]): T & object }
  | { (): T }
  | { new (...args: string[]): Function }

type RequiredKeys<T> = {
  [K in keyof T]: T[K] extends
    | { required: true }
    | { default: any }
    | BooleanConstructor
    | { type: BooleanConstructor }
    ? K
    : never
}[keyof T]

type OptionalKeys<T> = Exclude<keyof T, RequiredKeys<T>>

type ExtractFunctionPropType<
  T extends Function,
  TArgs extends Array<any> = any[],
  TResult = any
> = T extends (...args: TArgs) => TResult ? T : never

type ExtractCorrectPropType<T> = T extends Function
  ? ExtractFunctionPropType<T>
  : Exclude<T, Function>

// prettier-ignore
type InferPropType<T> = T extends null
  ? any // null & true would fail to infer
  : T extends { type: null | true }
    ? any // As TS issue https://github.com/Microsoft/TypeScript/issues/14829 // somehow `ObjectConstructor` when inferred from { (): T } becomes `any` // `BooleanConstructor` when inferred from PropConstructor(with PropMethod) becomes `Boolean`
    : T extends ObjectConstructor | { type: ObjectConstructor }
      ? Record<string, any>
      : T extends BooleanConstructor | { type: BooleanConstructor }
        ? boolean
          : T extends DateConstructor | { type: DateConstructor}
            ? Date
              : T extends FunctionConstructor
                ? Function
                : T extends Prop<infer V, infer D>
                  ? unknown extends V
                    ? D extends null | undefined
                      ? V
                      : D
                    : ExtractCorrectPropType<V>
                  : T

export type ExtractPropTypes<O> = O extends object
  ? { [K in RequiredKeys<O>]: InferPropType<O[K]> } &
      { [K in OptionalKeys<O>]?: InferPropType<O[K]> }
  : { [K in string]: any }

type DefaultKeys<T> = {
  [K in keyof T]: T[K] extends { default: any } ? K : never
}[keyof T]

// extract props which defined with default from prop options
export type ExtractDefaultPropTypes<O> = O extends object
  ? { [K in DefaultKeys<O>]: InferPropType<O[K]> }
  : {}