fetch nodejs polyfill

fetch.js

const https = require("https");
const fs = require("fs");

const fetch = (url, options) => {
  return new Promise((resolve, reject) => {
    const urlObj = new URL(url);

    const req = https.request(urlObj, options, (res) => {
      const response = new Response({
        statusCode: res.statusCode,
        headers: res.headers,
        url: res.url,
      });

      const buffers = [];

      res.on("data", (data) => {
        buffers.push(data);
      });

      res.on("end", () => {
        response.setBody(buffers);
        resolve(response);
      });
    });

    req.on("error", (e) => {
      reject(e);
    });

    req.end();
  });
};

class Response {
  headers;
  #body;
  url;
  statusCode;

  constructor({ headers, body, statusCode, url }) {
    this.headers = headers;
    this.body = body;
    this.statusCode = statusCode;
    this.url = url;
  }

  async json() {
    return JSON.parse(Buffer.concat(this.body).toString());
  }

  async text() {
    return Buffer.concat(this.body).toString();
  }

  async blob() {
    return Buffer.concat(this.body);
  }

  setBody(body) {
    this.body = body;
  }
}

async function main() {
  try {
    const res = await fetch(
      "https://cdn.pixabay.com/photo/2022/04/02/12/32/easter-tree-7106933__480.jpg",
      {
        method: "GET",
      }
    );

    // const data = await res.json();
    const data = await res.blob();
    fs.writeFileSync("./picture.jpg", data);
  } catch (e) {
    console.log(e.message);
  }
}

main();

module.exports = { fetch };

fetch.ts

export const fetch = (url: string, options: RequestOptions) => {
  return new Promise<Response>((resolve, reject) => {
    const urlObj = new URL(url);

    const req = https.request(urlObj, options, (res) => {
      const response = new Response({
        statusCode: res.statusCode,
        headers: res.headers,
        url: res.url,
      });

      const buffers: Buffer[] = [];

      res.on("data", (data) => {
        buffers.push(data);
      });

      res.on("end", () => {
        response.setBody(buffers);
        resolve(response);
      });
    });

    req.on("error", (e) => {
      reject(e);
    });

    req.end();
  });
};

class Response {
  headers: IncomingHttpHeaders;
  private body: Buffer[];
  url?: string;
  statusCode?: number;

  constructor({
    headers,
    body,
    statusCode,
    url,
  }: {
    headers: any;
    body?: any;
    statusCode?: number;
    url?: string;
  }) {
    this.headers = headers;
    this.body = body;
    this.statusCode = statusCode;
    this.url = url;
  } 

  async json() {
    return JSON.parse(Buffer.concat(this.body).toString());
  }

  async text() {
    return Buffer.concat(this.body).toString();
  }

  async blob() {
    return Buffer.concat(this.body);
  }

  setBody(body: Buffer[]) {
    this.body = body;
  }
}

async function main() {
  try {
    const res = await fetch(
      "https://cdn.pixabay.com/photo/2022/04/02/12/32/easter-tree-7106933__480.jpg",
      {
        method: "GET",
      }
    );

    // const data = await res.json();
    const data = await res.blob();
    fs.writeFileSync("./picture.jpg", data);
  } catch (e: any) {
    console.log(e.message);
  }
}

main();