feat: enhance fetch function with cookie handling

dist/index.js

@@ -3,6 +3,21 @@ import https from "https";
 import { URL } from "url";
 import querystring from "querystring";
 import zlib from "zlib";
+const parseCookies = (cookieHeader) => {
+    const cookies = {};
+    if (cookieHeader) {
+        cookieHeader.split(";").forEach(cookie => {
+            const [key, value] = cookie.split("=");
+            if (key && value)
+                cookies[key.trim()] = value.trim();
+        });
+    }
+    return cookies;
+};
+const formatCookies = (cookies) => Object.entries(cookies).map(([key, value]) => `${key}=${value}`).join("; ");
+const addCookiesToRequest = (cookies, headers) => {
+    headers["Cookie"] = formatCookies(cookies);
+};
 const decompress = (data, encoding) => {
     return encoding === "br" ? zlib.brotliDecompressSync(data) :
         encoding === "gzip" ? zlib.gunzipSync(data) :
@@ -27,8 +42,9 @@ const readData = (res, mode) => new Promise((resolve, reject) => {
     })
         .on("error", reject);
 });
-const fetch = async (urlString, options = {}, redirectCount = 0) => {
+const fetch = async (urlString, options = {}, redirectCount = 0, cookies = {}) => {
     const { protocol, hostname, pathname, search, port } = new URL(urlString);
+    options.followRedirects = options.followRedirects ?? true;
     if (options.signal?.aborted)
         throw new Error("Request aborted");
     const body = options.method === "POST" && options.body
@@ -47,19 +63,26 @@ const fetch = async (urlString, options = {}, redirectCount = 0) => {
             "Accept-Encoding": "br, gzip, deflate"
         }
     };
+    addCookiesToRequest(cookies, requestOptions.headers);
     return new Promise((resolve, reject) => {
         const requester = protocol === "https:" ? https : http;
         const req = requester.request(requestOptions, res => {
+            if (res.headers["set-cookie"])
+                cookies = parseCookies(res.headers["set-cookie"].join("; "));
             if (options.followRedirects && res.statusCode && res.statusCode >= 300 && res.statusCode < 400 && res.headers.location) {
                 if (redirectCount >= (options.maxRedirects || 5))
                     return reject(new Error("Max redirects exceeded"));
-                return resolve(fetch(new URL(res.headers.location, urlString).toString(), options, redirectCount + 1));
+                if (!res.headers.location)
+                    return reject(new Error("Redirect location not provided"));
+                const nextUrl = new URL(res.headers.location, urlString);
+                return resolve(fetch(nextUrl.toString(), options, redirectCount + 1, cookies));
             }
             if (res.statusCode && (res.statusCode < 200 || res.statusCode >= 300))
                 return reject(new Error(`Request failed with status code ${res.statusCode}`));
             resolve({
                 body: res,
                 headers: res.headers,
+                cookies: cookies,
                 text: () => readData(res, "text"),
                 json: () => readData(res, "json"),
                 buffer: () => readData(res, "buffer"),

src/index.ts

@@ -4,9 +4,12 @@ import { URL } from "url";
 import querystring from "querystring";
 import zlib from "zlib";
 
+type CookieStorage = Record<string, string>;
+
 type ResponseData = {
   body:        http.IncomingMessage;
   headers:     http.IncomingHttpHeaders;
+  cookies:     CookieStorage;
   text:        () => Promise<string>;
   json:        () => Promise<JSON>;
   buffer:      () => Promise<Buffer>;
@@ -21,6 +24,25 @@ interface ExtendedRequestOptions extends http.RequestOptions {
   signal?: AbortSignal;
 }
 
+const parseCookies = (cookieHeader: string | undefined): CookieStorage => {
+  const cookies: CookieStorage = {};
+  if(cookieHeader) {
+    cookieHeader.split(";").forEach(cookie => {
+      const [key, value] = cookie.split("=");
+      if(key && value)
+        cookies[key.trim()] = value.trim();
+    });
+  }
+  return cookies;
+};
+
+const formatCookies = (cookies: CookieStorage): string => 
+  Object.entries(cookies).map(([key, value]) => `${key}=${value}`).join("; ");
+
+const addCookiesToRequest = (cookies: CookieStorage, headers: http.OutgoingHttpHeaders): void => {
+  headers["Cookie"] = formatCookies(cookies);
+};
+
 const decompress = (
   data: Buffer,
   encoding: string | undefined
@@ -59,9 +81,11 @@ const readData = <T>(
 const fetch = async (
   urlString: string,
   options: ExtendedRequestOptions = {},
-  redirectCount: number = 0
+  redirectCount: number = 0,
+  cookies: CookieStorage = {}
 ): Promise<ResponseData> => {
   const { protocol, hostname, pathname, search, port } = new URL(urlString);
+  options.followRedirects = options.followRedirects ?? true;
 
   if(options.signal?.aborted)
     throw new Error("Request aborted");
@@ -85,20 +109,32 @@ const fetch = async (
     }
   };
 
+  addCookiesToRequest(cookies, requestOptions.headers!);
+
   return new Promise((resolve, reject) => {
     const requester = protocol === "https:" ? https : http;
     const req = requester.request(requestOptions, res => {
+      if(res.headers["set-cookie"])
+        cookies = parseCookies(res.headers["set-cookie"].join("; "));
+
       if(options.followRedirects && res.statusCode && res.statusCode >= 300 && res.statusCode < 400 && res.headers.location) {
         if(redirectCount >= (options.maxRedirects || 5))
           return reject(new Error("Max redirects exceeded"));
-        return resolve(fetch(new URL(res.headers.location, urlString).toString(), options, redirectCount + 1));
+
+        if(!res.headers.location)
+          return reject(new Error("Redirect location not provided"));
+
+        const nextUrl = new URL(res.headers.location, urlString);
+        return resolve(fetch(nextUrl.toString(), options, redirectCount + 1, cookies));
       }
 
       if(res.statusCode && (res.statusCode < 200 || res.statusCode >= 300))
         return reject(new Error(`Request failed with status code ${res.statusCode}`));
+
       resolve({
         body:        res,
         headers:     res.headers,
+        cookies:     cookies,
         text:        () => readData<string>(res, "text"),
         json:        () => readData<JSON>(res, "json"),
         buffer:      () => readData<Buffer>(res, "buffer"),