ts-essentials/dist/create-type-options/index.d.ts

All essential TypeScript types in one place

/**
 * This utility type forms an object type of `Options` by taking values from
 * `OverrideOptions`. If a value is not defined in `OverrideOptions`, the
 * utility type takes the value from `DefaultOptions`.
 *
 * The utility type intentionally restricts:
 * - `Options` to be required to know the object type form.
 * - `OverrideOptions` to be partial to make empty object assignable to it.
 * - `DefaultOptions` to be required to have fallback values for every property.
 */
export type CreateTypeOptions<Options extends Required<Options>, OverrideOptions extends Partial<Options>, DefaultOptions extends Required<Options>> = {
    [Key in keyof Options]: OverrideOptions[Key] extends Options[Key] ? OverrideOptions[Key] : DefaultOptions[Key];
};