type-samurai/src/_internal.d.ts

Advanced utility types for Typescript

import { And, AndArr } from "./and";
import { IsEqual } from "./equal";
import { Extends } from "./extends";
import { IsNever } from "./never";
import { Not } from "./not";
import { Or } from "./or";
import { Prettify } from "./prettify";
import { IsUnknown } from "./unknown";

export type OverWritable = {
  overwriteDefault?: boolean;
};

export type ApplyDefaultOptions<
  BaseOptions,
  Options extends BaseOptions,
  DefaultOptions extends BaseOptions,
  OverwriteRules,
  OverwriteDefault extends boolean = false
> = Prettify<{
  [K in keyof BaseOptions]-?: K extends keyof Options
    ? AndArr<
        [
          Extends<NonNullable<BaseOptions[K]>, object>,
          Not<IsNever<DefaultOptions[K]>>,
          Not<IsUnknown<BaseOptions[K]>>
        ]
      > extends true
      ? ApplyDefaultOptions<
          NonNullable<BaseOptions[K]>,
          Options[K],
          DefaultOptions[K],
          OverwriteRules[K & keyof OverwriteRules],
          OverwriteDefault
        > & {
          tra: "test";
        }
      : Or<
          IsEqual<OverwriteDefault, true>,
          And<
            Extends<K, keyof OverwriteRules>,
            Extends<OverwriteRules[K & keyof OverwriteRules], true>
          >
        > extends true
      ? Options[K]
      : Options[K] | DefaultOptions[K]
    : DefaultOptions[K];
}>;