123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149
import { CookieJar } from "./cookie_jar.ts";
// Max 20 redirects is fetch default settingconst MAX_REDIRECT = 20;
export type WrapFetchOptions = {  /** your own fetch function. defaults to global fetch. This allows wrapping your fetch function multiple times. */  fetch?: typeof fetch;  /** The cookie jar to use when wrapping fetch. Will create a new one if not provided. */  cookieJar?: CookieJar;};
interface ExtendedRequestInit extends RequestInit {  redirectCount?: number;}
const redirectStatus = new Set([301, 302, 303, 307, 308]);
function isRedirect(status: number): boolean {  return redirectStatus.has(status);}
// Credit <https://github.com/node-fetch/node-fetch/blob/5e78af3ba7555fa1e466e804b2e51c5b687ac1a2/src/utils/is.js#L68>.function isDomainOrSubdomain(destination: string, original: string): boolean {  const orig = new URL(original).hostname;  const dest = new URL(destination).hostname;
  return orig === dest || orig.endsWith(`.${dest}`);}
export function wrapFetch(options?: WrapFetchOptions): typeof fetch {  const { cookieJar = new CookieJar(), fetch = globalThis.fetch } = options ||    {};
  async function wrappedFetch(    input: RequestInfo | URL,    init?: ExtendedRequestInit,  ): Promise<Response> {    // let fetch handle the error    if (!input) {      return await fetch(input);    }    const cookieString = cookieJar.getCookieString(input);
    let originalRedirectOption: ExtendedRequestInit["redirect"];    const originalRequestUrl: string = (input as Request).url ||      input.toString();
    if (input instanceof Request) {      originalRedirectOption = input.redirect;    }    if (init?.redirect) {      originalRedirectOption = init?.redirect;    }
    const interceptedInit: ExtendedRequestInit = {      ...init,      redirect: "manual",    };
    const reqHeaders = new Headers((input as Request).headers || {});
    if (init?.headers) {      new Headers(init.headers).forEach((value, key) => {        reqHeaders.set(key, value);      });    }
    if (cookieString.length) {      reqHeaders.set("cookie", cookieString);    }        reqHeaders.delete("cookie2"); // Remove cookie2 if it exists, It's deprecated
    interceptedInit.headers = reqHeaders;
    const response = await fetch(input, interceptedInit as RequestInit);
    response.headers.forEach((value, key) => {      if (key.toLowerCase() === "set-cookie") {        cookieJar.setCookie(value, response.url);      }    });
    const redirectCount = interceptedInit.redirectCount ?? 0;    const redirectUrl = response.headers.has("location")      ? new URL(        response.headers.get("location")!.toString(),        originalRequestUrl,      ).toString()      : undefined;
    // Do this check here to allow tail recursion of redirect.    if (redirectCount > 0) {      Object.defineProperty(response, "redirected", { value: true });    }
    if (      // Return if response is not redirect      !isRedirect(response.status) ||      //  or location is not set      !redirectUrl ||      // or if it's the first request and request.redirect is set to 'manual'      (redirectCount === 0 && originalRedirectOption === "manual")    ) {      return response;    }
    if (originalRedirectOption === "error") {      await response.body?.cancel();      throw new TypeError(        `URI requested responded with a redirect and redirect mode is set to error: ${response.url}`,      );    }
    // If maximum redirects are reached throw error    if (redirectCount >= MAX_REDIRECT) {      await response.body?.cancel();      throw new TypeError(        `Reached maximum redirect of ${MAX_REDIRECT} for URL: ${response.url}`,      );    }
    await response.body?.cancel();
    interceptedInit.redirectCount = redirectCount + 1;
    const filteredHeaders = new Headers(interceptedInit.headers);
    // Do not forward sensitive headers to third-party domains.    if (!isDomainOrSubdomain(originalRequestUrl, redirectUrl)) {      for (const name of ["authorization", "www-authenticate"]) { // cookie headers are handled differently        filteredHeaders.delete(name);      }    }
    if (interceptedInit.method === "POST") {      filteredHeaders.delete("content-length");      interceptedInit.method = "GET";      interceptedInit.body = undefined;    }    interceptedInit.headers = filteredHeaders;
    return await wrappedFetch(redirectUrl, interceptedInit as RequestInit);  }
  return wrappedFetch;}