types.ts

// SPDX-License-Identifier: MIT-0
// Copyright 2024 Amazon

type AnyFn = (...args: any[]) => any;
type VoidFn = () => void;
type NoArgsFn = () => any;
type Thunk<F extends AnyFn> = () => ReturnType<F>;
type Wrapper<F extends AnyFn> = (...args: Parameters<F>) => ReturnType<F>;
type VoidWrapper<F extends AnyFn> = (...args: Parameters<F>) => void;

type LinkAs = 'audio' | 'document' | 'fetch' | 'font' | 'image' | 'object'
            | 'script' | 'style' | 'track' | 'video' | 'worker';

// Opaque<T, K> cannot be assigned from T
// T is assignable from Opaque<T, K>
type Opaque<T, K> = T & { __opaque__: K };
// StrongOpaque<T, K> cannot be assigned from T
// T cannot be assigned from StrongOpaque<T, K>
type StrongOpaque<T, K> = (T & { __opaque__: K }) | { __opaque__: K };

type EncodedURIComponent = Opaque<string, 'EncodedURIComponent'>;
type URLString = Opaque<string, 'URLString'>;

type WithReferrerPolicy<T> = T & {referrerPolicy: ReferrerPolicy};

interface _FeaturePolicy {
  allowsFeature: () => true;
  allowedFeatures: () => string[];
  features: () => string[];
  getAllowlistForFeature: (feature: string) => string[];
}

type WithFeaturePolicy<T> = T & {featurePolicy?: _FeaturePolicy};

interface RequestInitExt extends RequestInit {
  referrerPolicy?: ReferrerPolicy;
  priority?: 'high' | 'low' | 'auto';
}

interface ElementCreator {
  <K extends "iframe">(target: Document | HTMLElement, type: K): WithFeaturePolicy<HTMLIFrameElement>;
  <K extends keyof HTMLElementTagNameMap>(target: Document | HTMLElement, type: K): HTMLElementTagNameMap[K];
}