Bun v0.2.0

To upgrade: ```bash bun upgrade ``` To install: ```bash curl https://bun.sh/install | bash ``` <details> <summary>If you have any problems upgrading</summary> Run the install script (you can run it multiple times): ```bash curl https://bun.sh/install | bash ``` </details> ## Introducing Bun v0.2.0  New: - `bun --hot` brings hot reloading &amp; zero-downtime restarts to Bun's JavaScript runtime - `Bun.spawn` and `Bun.spawnSync` (process spawning API) - `Request.body` - incoming HTTP request body streaming with `ReadableStream` - _tons_ of bug fixes & reliability improvements to `Bun.serve` (HTTP server) and `fetch()` (HTTP client) - Rewrote `setTimeout` and `setInterval` for better performance and reliability - 2.7x+ lower memory usage for `Bun.serve` and anything using `Response` objects - `"imports"` in package.json (`"#foo"` imports) works now https://github.com/oven-sh/bun/commit/21770eb0f31a43b3d6127ab957e271d029d6bc1b - `"bun:test"` gets ~300x faster when using http server, websockets, etc https://github.com/oven-sh/bun/commit/524e48a81dfc6106ffcdd07b6fd035000b03146c - Incrementally write files with `Bun.file(path).writer()` - 30% faster Array.prototype.indexOf for strings (thanks @Constellation) - 37% faster Array.prototype.map (thanks @Constellation) - 1.4x - 4x faster String.prototype.substring (thanks @Constellation) - 2.8x faster String.prototype.replace (thanks @Constellation) - `new Blob(["hello world"])` is now [75x faster in Bun than Node](https://twitter.com/jarredsumner/status/1573204676782489600) - https://github.com/oven-sh/bun/commit/2c1926993bc4d94f9e7bc4d171217a707efd385c Breaking: - `bun run` and `bun` CLI arguments parsing has been changed so that anything after `bun run <file-or-script>` or `bun <file>` is passed through verbatim. This fixes a number of bugs with CLI argument parsing in both bun as a runtime and when used as a package.json `"scripts"` runner. ```bash # before, server.js wouldn't see the --port argument bun run server.js --port 3000 ``` - `process.version` now reports a fake Node.js version instead of Bun's version. This is for compatibility with many npm packages that check for Node.js version to enable/disable features. To get Bun's version, use `Bun.version` or `process.versions.bun`. - `Bun.serve().hostname` should return the hostname instead of the origin. This is a breaking change because it affects how URLs may be printed if you were using this getter before. https://github.com/oven-sh/bun/commit/e15fb6b9b220510df049e782d4f2f6eb3150d069 ## `bun --hot`: hot reloads on the server `bun --hot` lets you see code changes immediately, without restarting your server. Unlike popular file watchers like nodemon, `bun --hot` preserves some of the state of your app, meaning in-flight HTTP requests don't get interrupted. <table> <tr> <th width="800" align="center"> Bun v0.2.0 </th> <th width="800" align="center"> Nodemon </th> </tr> </table>  To use it with Bun's HTTP server (automatic): `server.ts` (vanilla JavaScript works too) ```ts // The global object is preserved across code reloads // You can use it to store state, for now until Bun implements import.meta.hot. const reloadCount = globalThis.reloadCount || 0; globalThis.reloadCount = reloadCount + 1; export default { fetch(req: Request) { return new Response(`Code reloaded ${reloadCount} times`, { headers: { "content-type": "text/plain" }, }); }, }; ``` Then, run: ```bash bun --hot server.ts ``` You can also use `bun run`: ```bash bun run --hot server.ts ``` For more information, see `bun --hot` section in Bun's readme. ## `Bun.spawn` spawn processes in Bun `Bun.spawn` efficiently spawns a new process in Bun. ```ts import { spawn } from "bun"; const { stdout } = await spawn(["echo", "hello world"]); console.log( await new Response( // stdout is a ReadableStream stdout ).text() ); // "hello world" ``` `Bun.spawn` is flexible. `stdin` can be a `Response`, `Blob`, `Request`, `ArrayBuffer`, `ArrayBufferView`, `Bun.file`, `"pipe"` or `number`. ```ts import { spawn } from "bun"; const { stdout } = spawn({ cmd: ["esbuild"], // using fetch() stdin: await fetch( "https://raw.githubusercontent.com/oven-sh/bun/main/examples/hashing.js" ), }); const text = await new Response( // stdout is a ReadableStream here stdout ).text(); console.log(text.slice(0, 128), "..."); // const input = "hel... ``` `stdout` and `stderr` return `ReadableStream`s when `"pipe"` is used. ## Request.body & Response.body return a `ReadableStream` This fixes https://github.com/oven-sh/bun/issues/530 You can read `Request` & `Response` objects bodies as a ReadableStream now ## `ReadableStream` now supports async iterators This works now: ```ts const body = new Response(["hello"]).body; const chunks = []; for await (const chunk of body) { chunks.push(chunk); } ``` Previously, you had to call `getReader()` like this: ```ts const reader = body.getReader(); const chunks = []; while (true) { const { done, value } = await reader.read(); if (done) { break; } chunks.push(value); } ``` ## HTTP request body streaming `Bun.serve` now supports streaming request bodies. This is useful for large file uploads. ```ts import { serve } from "bun"; serve({ async fetch(req) { // body is a ReadableStream const body: ReadableStream = req.body; const id = `upload.${Date.now()}.txt`; const writer = Bun.file(id).writer(); for await (const chunk of body) { writer.write(chunk); } const wrote = await writer.close(); return Response.json({ wrote, id, type: req.headers.get("Content-Type") }); }, }); ``` ## `"imports"` support in `package.json` This release adds support for the [`imports` field in package.json](https://nodejs.org/api/packages.html#imports)  ## Reduced memory usage for Bun.serve() Bun wasn't correctly reporting memory usage for `Request`, `Response`, and `Blob` objects to JavaScriptCore, causing the garbage collector to be unaware of how much memory was really in use for http responses/requests.  ## bun:test performance improvements An event loop bug in `bun:test` caused the process the idle for awhile. Now bun's own http server tests run > 10x faster.  ### Bug fixes: - Fix how console.log handle circular by @zhiyuang in https://github.com/oven-sh/bun/pull/1293 - Fix nested modules bin executable issue by @zhiyuang in https://github.com/oven-sh/bun/pull/1299 - Fix install error when node_modules already in npm package by @zhiyuang in https://github.com/oven-sh/bun/pull/1301 - Fix fetch response redirected by @zhiyuang in https://github.com/oven-sh/bun/pull/1303 - Fix occasional crash with .json() [https://github.com/oven-sh/bun/commit/dfefb05b10e57e01faab0d633fc9538a571a566f] - Fix incorrect hostname logic in Bun.serve() https://github.com/oven-sh/bun/commit/167948f5c3afc0a4dc482222e42bd255951084ff - Allow .env files to define the same key multiple times https://github.com/oven-sh/bun/commit/e94e6d8d95061c8bdb07ce96bc836689f49aafdd - Fix crash when creating an empty array https://github.com/oven-sh/bun/commit/16b1e84138056774684b5e769a20dabd787d069c - Fix console.log not printing an empty line https://github.com/oven-sh/bun/commit/b733125085a5746af121ce6d7b67eb45fb8e85e3 - Fix potential crash when TS code has an unexpected ")" https://github.com/oven-sh/bun/commit/a8ab18bd50b3a98c65c6ce96bd75d87d7893df12 - Support all ArrayBufferView in all hashing functions and node fs functions https://github.com/oven-sh/bun/commit/9d7bcac680c5f32d3fa89d9e47972957279a1a05 - Fix DotEnv Loader ignoring error log level - https://github.com/oven-sh/bun/commit/906e97223a3dd95801bc0d12f62314719c554fd6 - Fix missing path/posix and path/win32 https://github.com/oven-sh/bun/commit/dbccfc2b26371c921f3b3a55b03e8bb4a103444f - Fix cancel not working in some cases in `ReadableStream` - Fix crash in TextEncoder with rope strings that happens sometimes https://github.com/oven-sh/bun/commit/6b7a0c1d3fde32b6e3ded85456d0721c34aa9219 - `bun:sqlite` Fix crash in Database.deserialize https://github.com/oven-sh/bun/commit/9fd00727406b0170fa2d3bb43973ff8d78e7bb76 - Bun segfalts when tsconfig specifies a jsxFactory #1269 - unable to use EventEmitter with "require", empty object instead of a class #1284 - segmentation fault on "napi_wrap" when trying to call a loaded .node extension #1286 - "assert is not a function" error when calling the assert module as a function #941 More changes: - `Bun.which(bin)`: find the path to a command - `process` now extends `EventEmitter` - Minor tweaks to `bun:test` output. now it includes "expect calls" <img width="279" alt="image" src="https://user-images.githubusercontent.com/709451/195565842-833615b9-b176-4363-ab48-c226c1bd722d.png"> - `bun:test` print test failures at the bottom - https://github.com/oven-sh/bun/commit/c57b32fa0cdeaf7f1490bd6af9c5248a92c71ea0 - `navigator.userAgent` and `navigator.hardwareConcurrency` are now globals - `require("tty").isatty` works now - `require("fs").rm` works now - Implement `console.count` and `console.countReset` - https://github.com/oven-sh/bun/commit/4060afb7c70dd3ba037bd23c813c22032e2dabe5  - Internal data structures for `fetch()` use 82% less memory (9.8 KB -> 1.8 KB) - `Bun.version` reports Bun's version number - `Bun.revision` reports the git commit SHA used at the time Bun was compiled ## All the PRs * fix: add destination to ADD command in Dockerfile by @DarthBenro008 in https://github.com/oven-sh/bun/pull/1268 * test: Promisify basic tests by @albertpurnama in https://github.com/oven-sh/bun/pull/1018 * Add `body` to `Response` and `Request` by @Jarred-Sumner in https://github.com/oven-sh/bun/pull/1255 * Fix how console.log handle circular by @zhiyuang in https://github.com/oven-sh/bun/pull/1293 * docs(thread_pool): comment readability improvements by @ryanrussell in https://github.com/oven-sh/bun/pull/1241 * Fix nested modules bin executable issue by @zhiyuang in https://github.com/oven-sh/bun/pull/1299 * Fix install error when node_modules already in npm package by @zhiyuang in https://github.com/oven-sh/bun/pull/1301 * Fix fetch response redirected by @zhiyuang in https://github.com/oven-sh/bun/pull/1303 ## New Contributors * @DarthBenro008 made their first contribution in https://github.com/oven-sh/bun/pull/1268 * @albertpurnama made their first contribution in https://github.com/oven-sh/bun/pull/1018 * @zhiyuang made their first contribution in https://github.com/oven-sh/bun/pull/1293 **Full Changelog**: https://github.com/oven-sh/bun/compare/bun-v0.1.13...bun-v0.2.0