Bun v0.2.2

To upgrade: ```bash bun upgrade ``` To install: ```bash curl https://bun.sh/install | bash ``` TLDR: - TCP/TLS Socket API - WebCrypto API - `fs.createReadStream` works now - `Bun.peek` - Install Bun with Homebrew - Several bug fixes ## TCP sockets Bun now has support for TCP clients and servers. You can use it to implement database clients, game servers, or anything else that needs to use TCP instead of HTTP. A TCP echo server runs 24% faster [in Bun](https://github.com/oven-sh/bun/blob/main/bench/snippets/tcp-echo.bun.ts) compared to [Node](https://github.com/oven-sh/bun/blob/main/bench/snippets/tcp-echo.node.mjs):  This API is designed to be fast. Instead of promises or assigning callbacks for each socket, like the Node.js EventEmitter or the standard WebSocket API, callbacks are defined once for optimal performance and better code readability. ### Start a TCP server ```js import { listen } from "bun"; listen({ hostname: "localhost", port: 8080, socket: { open(socket) {}, data(socket, data) { console.log(data instanceof Uint8Array); // true }, drain(socket) {}, close(socket) {}, error(socket, error) {}, }, }); ``` ### Start a TCP client ```js import { connect } from "bun"; connect({ hostname: "localhost", port: 8080, socket: { data(socket, data) { console.log("Received:", data); }, }, }); ``` There is also support for: * Hot-reloading a TCP socket without downtime * Assigning custom data to a socket * TLS/SSL support You can read more about TCP sockets in the [README](https://github.com/oven-sh/bun#bunlisten--bunconnect---tcptls-sockets). This API is very new and I imagine there are still some bugs to fix. Please file issues about any bugs you run into! ## Bug fixes Bun has a special transform for importing builtin modules which converts them from asynchronous ESM imports into synchronous ESM `import.meta.require`. A transpiler bug when `default` was imported in these builtin Bun modules along with other named imports caused a runtime error: ```ts // this code would break import fs, {writeFileSync} from 'fs'; // but this code worked import * as fs from 'fs'; ``` The bug was due to how Bun's transpiler rewrote those imports. In this case, `default` is equivalent to the namespace object (only for these builtin modules which may not actually point to JavaScript source code) Now, Bun transpiles the above into: ```ts var fs = import.meta.require("node:fs"); // note: live bindings are not preserved var {writeFileSync} = fs; ``` --- When an import fails to resolve at build time, Bun throws a `ResolveError`. `ResolveError` includes a `position` object that exposes detailed line & column information about where the file was originally imported. There was a bug where Bun would crash if you attempted to access the `position` object when it came from an `await import` which imported another file that failed to resolve File A: ```js import { expect, it, describe } from "bun:test"; describe("ResolveError", () => { it("position object does not segfault", async () => { try { await import("./file-b"); } catch (e) { expect(Bun.inspect(e.position).length > 0).toBe(true); } }); }); ``` `file-b.js`: ```js import "./does-not-exist.js"; ``` This bug has been fixed. --- Error handling logic for `new Response(Bun.file(fileDescriptorAsANumber))` when used with the HTTP server expected it to be used with file paths instead of file descriptor numbers, causing a crash. Thanks to @sno2 for [the fix](https://github.com/oven-sh/bun/commit/b3434a8b883ee98324cea2c7d14dd988e6bb8adc). ```js export default { // This would crash due to incorrect error handling logic fetch(req) { return new Response(Bun.file(123)); } } ``` --- An edgecase involving hex-escaped RegExp literals with lookbehinds caused our Oniguruma polyfill from v0.2.1 to throw an error. This was [fixed](https://github.com/oven-sh/bun/pull/1363) thanks to @dylan-conway --- More bug fixes: - [Fix calling ws.publish inside close when other clients are connected](https://github.com/oven-sh/bun/commit/9f16906499c812eb82a982307511c454dec769ed) - [Fix crash in Node Streams highWaterMark](https://github.com/oven-sh/bun/commit/da9b2452a7d44705f33ccde29c970cc510870264) - [Fix infinite loop involving regexp lookbehinds](https://github.com/oven-sh/bun/commit/c940f00e2d49ea37ac69589a9a160a43df91eeb6) - [new Response(null) caused a crash](https://github.com/oven-sh/bun/commit/14cec299f5170b8ed35eed28e53b88724b8cc04f) (a regression from v0.2.0) - The `ReadableStream.prototype.tee` function did not work when used with `"direct"` streams 360a007f160b6935140dc75003a503059ff23976 - Fix missing error logging @zhiyuang in https://github.com/oven-sh/bun/pull/1387 - Fix undefined error object in `error` handler in `Bun.serve` @zhiyuang in https://github.com/oven-sh/bun/pull/1387 - Fix spawn exitcode by @zhiyuang in https://github.com/oven-sh/bun/pull/1371 ## `Bun.peek` Sometimes you have code that is `async`, but you _know_ it is not actually `async`. The new `peek` function will allow you to read a promise's result without await or .then, but only if the promise has already fulfilled or rejected. ```js import { peek } from "bun"; const promise = Promise.resolve("immediate"); const result = peek(promise); // no await! console.log(result); // "immediate" ``` It is useful for performance-sensitive code where you want to reduce the number of extra microticks. It's an advanced API and you (probably) shouldn't use it unless you know what you're doing. You can read more about `peek` in the [README](https://github.com/oven-sh/bun/#bunpeek---read-a-promise-without-resolving-it). ## Node.js streams In addition to new APIs, we continue to make progress towards Node.js compatibility. Bun now supports [`fs.createReadStream`](https://nodejs.org/api/fs.html#fscreatereadstreampath-options) and has generally improved support for Node.js streams. ```js import { createReadStream } from "node:fs"; // Reads the first 100 bytes of a file const reader = createReadStream("example.txt", { encoding: "utf-8", start: 0, end: 100, }); reader.on("data", (chunk) => { console.log(chunk); }); ``` ## WebCrypto API The standard [WebCrypto](https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto) API is now implemented, thanks to the many contributors at [WebKit](https://github.com/WebKit). WebCrypto is a low-level API, so we only recommend using it when you know a little more than a thing or two about cryptography. However, there are popular libraries that depend on WebCrypto that you can now use with Bun. Here's an example using a package that depends on WebCrypto: [`jose`](https://github.com/panva/jose) by @panva. ```js const jwt = await new jose.SignJWT({ 'urn:example:claim': true }) .setProtectedHeader({ alg: 'ES256' }) .setIssuedAt() .setIssuer('urn:example:issuer') .setAudience('urn:example:audience') .setExpirationTime('2h') .sign(privateKey) console.log(jwt) ``` ## Homebrew You can now install or upgrade Bun with our official [Homebrew tap](https://github.com/oven-sh/homebrew-bun). ```bash brew tap oven-sh/bun brew install bun ``` You can also install a specific version. ```bash brew install [email protected] ``` You can also upgrade with either `brew` or `bun`. ```bash brew upgrade bun bun upgrade # still works ``` ## All the PRs * Improve issue templates by @Electroid in https://github.com/oven-sh/bun/pull/1353 * Cache dir loader: Prefer `$BUN_INSTALL` and `$XDG_CACHE_HOME` to `$HOME`. by @lgarron in https://github.com/oven-sh/bun/pull/1351 * Fix Bun.serve error handler error param by @zhiyuang in https://github.com/oven-sh/bun/pull/1359 * chore: remove outdated `var` usages by @sno2 in https://github.com/oven-sh/bun/pull/1364 * Fix spawn exitcode by @zhiyuang in https://github.com/oven-sh/bun/pull/1371 * fix(fetch): stop `new Response(null)` from segfaulting by @sno2 in https://github.com/oven-sh/bun/pull/1383 * Add Web Crypto API by @Jarred-Sumner in https://github.com/oven-sh/bun/pull/1384 * fix(web): stop segfault on invalid fd error by @sno2 in https://github.com/oven-sh/bun/pull/1386 * oniguruma regex lookbehind and multibyte hex fix by @dylan-conway in https://github.com/oven-sh/bun/pull/1363 * TCP & TLS Socket API by @Jarred-Sumner in https://github.com/oven-sh/bun/pull/1374 * Fix lexer expected token error by @zhiyuang in https://github.com/oven-sh/bun/pull/1387 * Update Dev Containers extension name by @jpaquim in https://github.com/oven-sh/bun/pull/1393 * Minor fixes to README.md by @jpaquim in https://github.com/oven-sh/bun/pull/1395 ## New Contributors * @Electroid made their first contribution in https://github.com/oven-sh/bun/pull/1353 * @lgarron made their first contribution in https://github.com/oven-sh/bun/pull/1351 * @jpaquim made their first contribution in https://github.com/oven-sh/bun/pull/1393 **Full Changelog**: https://github.com/oven-sh/bun/compare/bun-v0.2.1...bun-v0.2.2