bun.sh/test/js/web/fetch/fetch-gzip.test.ts

import { Socket } from "bun";
import { beforeAll, expect, it } from "bun:test";
import { gcTick } from "harness";
import path from "path";

const gzipped = path.join(import.meta.dir, "fixture.html.gz");
const html = path.join(import.meta.dir, "fixture.html");
let htmlText: string;
beforeAll(async () => {
  htmlText = (await Bun.file(html).text()).replace(/\r\n/g, "\n");
});

it("fetch() with a buffered gzip response works (one chunk)", async () => {
  using server = Bun.serve({
    port: 0,

    async fetch(req) {
      gcTick(true);
      return new Response(require("fs").readFileSync(gzipped), {
        headers: {
          "Content-Encoding": "gzip",
          "Content-Type": "text/html; charset=utf-8",
        },
      });
    },
  });
  gcTick(true);

  const res = await fetch(server.url, { verbose: true });
  gcTick(true);
  const arrayBuffer = await res.arrayBuffer();
  const clone = new Buffer(arrayBuffer);
  gcTick(true);
  await (async function () {
    const second = Buffer.from(htmlText);
    gcTick(true);
    expect(second.equals(clone)).toBe(true);
  })();
  gcTick(true);
});

it("fetch() with a redirect that returns a buffered gzip response works (one chunk)", async () => {
  using server = Bun.serve({
    port: 0,

    async fetch(req) {
      if (req.url.endsWith("/redirect"))
        return new Response(await Bun.file(gzipped).arrayBuffer(), {
          headers: {
            "Content-Encoding": "gzip",
            "Content-Type": "text/html; charset=utf-8",
          },
        });

      return Response.redirect("/redirect");
    },
  });

  const url = new URL("hey", server.url);
  const res = await fetch(url, { verbose: true });
  const text = (await res.text()).replace(/\r\n/g, "\n");
  expect(text).toEqual(htmlText);
});

it("fetch() with a protocol-relative redirect that returns a buffered gzip response works (one chunk)", async () => {
  using server = Bun.serve({
    port: 0,

    async fetch(req, server) {
      if (req.url.endsWith("/redirect"))
        return new Response(await Bun.file(gzipped).arrayBuffer(), {
          headers: {
            "Content-Encoding": "gzip",
            "Content-Type": "text/html; charset=utf-8",
          },
        });

      const { host } = server.url;
      return Response.redirect(`://${host}/redirect`);
    },
  });

  const res = await fetch(new URL("hey", server.url), { verbose: true });
  expect(new URL(res.url)).toEqual(new URL("redirect", server.url));
  expect(res.redirected).toBe(true);
  expect(res.status).toBe(200);
  const text = (await res.text()).replace(/\r\n/g, "\n");
  expect(text).toEqual(htmlText);
});

it("fetch() with a gzip response works (one chunk, streamed, with a delay)", async () => {
  using server = Bun.serve({
    port: 0,

    fetch(req) {
      return new Response(
        new ReadableStream({
          type: "direct",
          async pull(controller) {
            await 2;

            const buffer = await Bun.file(import.meta.dir + "/fixture.html.gz").arrayBuffer();
            controller.write(buffer);
            controller.close();
          },
        }),
        {
          headers: {
            "Content-Encoding": "gzip",
            "Content-Type": "text/html; charset=utf-8",
            "Content-Length": "1",
          },
        },
      );
    },
  });

  const res = await fetch(server.url);
  const text = (await res.text()).replace(/\r\n/g, "\n");
  expect(text).toEqual(htmlText);
});

it("fetch() with a gzip response works (multiple chunks, TCP server)", async done => {
  const compressed = await Bun.file(gzipped).arrayBuffer();
  var socketToClose!: Socket;
  let pending,
    pendingChunks = [];
  const server = Bun.listen({
    hostname: "localhost",
    port: 0,
    socket: {
      drain(socket) {
        if (pending) {
          while (pendingChunks.length) {
            const chunk = pendingChunks.shift();
            const written = socket.write(chunk);

            if (written < chunk.length) {
              pendingChunks.push(chunk.slice(written));
              return;
            }
          }
          const resolv = pending;
          pending = null;
          resolv();
        }
      },
      async open(socket) {
        socketToClose = socket;

        var corked: any[] = [];
        var cork = true;
        let written = 0;
        let pendingChunks = [];
        async function write(chunk: any) {
          let defer = Promise.withResolvers();

          if (cork) {
            corked.push(chunk);
          }

          if (!cork && corked.length) {
            const toWrite = corked.join("");
            const wrote = socket.write(toWrite);
            if (wrote !== toWrite.length) {
              pendingChunks.push(toWrite.slice(wrote));
            }
            corked.length = 0;
          }

          if (!cork) {
            if (pendingChunks.length) {
              pendingChunks.push(chunk);
              pending = defer.resolve;
              await defer.promise;
              defer = Promise.withResolvers();
              pending = defer.resolve;
            }

            const written = socket.write(chunk);
            if (written < chunk.length) {
              console.log("written", written);
              pendingChunks.push(chunk.slice(written));
              pending = defer.resolve;
              await defer.promise;
              defer = Promise.withResolvers();
              pending = defer.resolve;
            }
          }

          const promise = defer.promise;
          if (pendingChunks.length) {
            pending = promise;
            await promise;
          } else {
            pending = null;
          }
        }
        await write("HTTP/1.1 200 OK\r\n");
        await write("Content-Encoding: gzip\r\n");
        await write("Content-Type: text/html; charset=utf-8\r\n");
        await write("Content-Length: " + compressed.byteLength + "\r\n");
        await write("X-WTF: " + "lol".repeat(1000) + "\r\n");
        await write("\r\n");
        for (var i = 100; i < compressed.byteLength; i += 100) {
          cork = false;
          await write(compressed.slice(i - 100, i));
        }
        await write(compressed.slice(i - 100));
        await write("\r\n");

        socket.flush();
      }
    },
  });
  await 1;

  const res = await fetch(`http://${server.hostname}:${server.port}`);
  const text = (await res.text()).replace(/\r\n/g, "\n");
  expect(text).toEqual(htmlText);
  socketToClose.end();
  server.stop();
  done();
});