---
title: Bun v0.6.0
description: A new JavaScript bundler, standalone executables, and lots of new features and improvements
date: "2023-05-16T12:00:00+00:00"
author: jarred
draft: false
---

{% callout %}
We're hiring [C/C++ and Zig engineers](/careers) to build the future of JavaScript! [See job listings →](/careers)
{% /callout %}

This is the biggest release of Bun yet.

Bun now has a built-in JavaScript and TypeScript bundler and minifier. Use it to bundle frontend apps or bundle your code into a standalone executable.

We've also been busy improving performance and fixing bugs as-per usual: `writeFile()` gets up to 20% faster on Linux, lots of bug fixes to Node.js compatiblity and Web API compatiblity, support for TypeScript 5.0 syntax, and various fixes to `bun install`.

## Bun's new JavaScript bundler & minifier

The focus of this release is Bun's new JavaScript bundler, but the bundler is just the beginning of a larger project. In the next couple months, we'll be announcing `Bun.App` — a "super-API" that stitches together Bun's native-speed bundler, HTTP server, and file system router into a cohesive whole.

It can be used using the `bun build` CLI command or the new `Bun.build()` JavaScript API.

{% codetabs %}

```ts#JavaScript
Bun.build({
  entrypoints: ["./src/index.tsx"],
  outdir: "./build",
  minify: true,
  // ...
});
```

```bash#CLI
$ bun build ./src/index.tsx --outdir ./build --minify
```

{% /codetabs %}

{% callout %}

To learn more, check out our [blog post](/blog/bun-bundler) introducing the Bun bundler.

{% /callout %}

## Standalone executables

You can now create standalone executables with `bun build`.

```sh
bun build --compile ./foo.ts
```

This lets you distribute your app as a single executable file, without requiring users to install Bun.

```sh
./foo
```

You can also minify it to improve startup performance for large apps:

```js
bun build --minify --compile ./three.ts
  [32ms]  minify  -123 KB (estimate)
  [50ms]  bundle  456 modules
 [107ms] compile  three
```

This is powered by Bun's new JavaScript bundler and minifier.

{% raw %}

<blockquote class="twitter-tweet"><p lang="en" dir="ltr">Standalone executables are coming in Bun v0.6.0 <a href="https://t.co/eaUeFtKisL">pic.twitter.com/eaUeFtKisL</a></p>&mdash; Jarred Sumner (@jarredsumner) <a href="https://twitter.com/jarredsumner/status/1657750890349215744?ref_src=twsrc%5Etfw">May 14, 2023</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>

{% /raw %}

## `import.meta.main`

You can now use `import.meta.main` to check if the current file is the entry point that started bun. This is useful for CLIs to determine if the current file is what started the app.

For example, if you have a file called `index.ts`:

{% codetab %}

```ts#index.ts
console.log(import.meta.main);
```

{% /codetab %}

And you run it:

```js
$ bun ./index.ts
true
```

But if you import it:

{% codetab %}

```ts#other.ts
import "./index.ts";
```

{% /codetab %}

And run it:

```js
$ bun ./other.ts
false
```

## Improvements to `bun test`

- `bun test` now reports time taken to run tests

{% raw %}

<blockquote class="twitter-tweet"><p lang="en" dir="ltr">in the next version of bun<br><br>bun:test prints out how long each test took<br><br>slow tests are highlighted yellow <a href="https://t.co/yXDSJrkYBu">pic.twitter.com/yXDSJrkYBu</a></p>&mdash; Jarred Sumner (@jarredsumner) <a href="https://twitter.com/jarredsumner/status/1656569942354042880?ref_src=twsrc%5Etfw">May 11, 2023</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>

{% /raw %}

- `describe.skip` has been implemented (thanks to [\_yogr](https://twitter.com/_yogr))

- `expect().toBeEven()` and `expect().toBeOdd()` has been implemented (thanks to [will-richards-ii](https://github.com/will-richards-ii))

## Faster `fs.writeFile` on Linux

{% raw %}

<blockquote class="twitter-tweet"><p lang="en" dir="ltr">In the next version of Bun<br><br>fs.writeFile gets 20% faster for large files on Linux <a href="https://t.co/QgWhBoiz2c">pic.twitter.com/QgWhBoiz2c</a></p>&mdash; Jarred Sumner (@jarredsumner) <a href="https://twitter.com/jarredsumner/status/1651533306868137984?ref_src=twsrc%5Etfw">April 27, 2023</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>

{% /raw %}

## Transpiler improvements

This release also introduces many improvements to the transpiler. Here are some of the highlights:

- Parser support for [TypeScript 5.0](https://devblogs.microsoft.com/typescript/announcing-typescript-5-0/).
- Parser support for [import attributes](https://github.com/tc39/proposal-import-assertions).
- Some npm packages threw "ReferenceError: Cannot access uninitialized variable" errors on import due to a bug with cyclical imports in Bun's transpiler. This has been fixed.
- Support for `// @jsx`, `// @jsxImportSource`, and `// @jsxFragment` comments.
- Dead code elimination for unused global constructor function calls like `new Set()`.
- String template literal concatenation like `foo${1}${"2"}${'3'}` -> `foo123`.
- Parser bugfixes for the deprecated ES5 [`with` statement](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/with).

A big thanks to [@kzc](https://github.com/kzc) for many helpful bug reports.

## Node.js compatibility

- `tls.Server` has basic support (previously, not implemented)
- `fs.promises.constants` is now exported correctly (previously, it was missing)
- `node:http`'s server module now (correctly) accepts a `callback` argument
- `Timer.refresh()` now works as expected
- Fixed `mkdtemp` and `mkdtempSync` errors

## Web API compatibility

- `new Request("http://example.com", otherRequest).url` would previously return the url of `otherRequest` instead of `"http://example.com"`. This has been fixed.
- `Bun.file(path).lastModified` has been added, which is similar to the [`File` API's `lastModified` property](https://developer.mozilla.org/en-US/docs/Web/API/File/lastModified)
- Supported `redirect: "error"` in `fetch()`
- Fixed `fetch.bind`, `fetch.call`, and `fetch.apply` not working

## Changelog

{% table %}

---

- [`#2556`](https://github.com/oven-sh/bun/pull/2556)
- Implemented `import.meta.main` by [@Jarred-Sumner](https://github.com/Jarred-Sumner)

---

- [`#2561`](https://github.com/oven-sh/bun/pull/2561)
- Removed `Object.prototype` from `node:path` exports by [@privatenumber](https://github.com/privatenumber)

---

- [`#2557`](https://github.com/oven-sh/bun/pull/2557)
- Fixed `Bun.deepEquals()` with accessors and holed arrays by [@dylan-conway](https://github.com/dylan-conway)

---

- [`#2554`](https://github.com/oven-sh/bun/pull/2554)
- Fixed issues with `fetch({ proxy })` by [@cirospaciari](https://github.com/cirospaciari)

---

- [`#2491`](https://github.com/oven-sh/bun/pull/2491)
- Implemented `BunFile.lastModified` by [@zhongweiy](https://github.com/zhongweiy)

---

- [`#2567`](https://github.com/oven-sh/bun/pull/2567)
- Fixed `constants` export from `node:fs/promises` by [@paperclover](https://github.com/paperclover)

---

- [`#2552`](https://github.com/oven-sh/bun/pull/2552)
- Implemented basic support for `tls.Server` by [@cirospaciari](https://github.com/cirospaciari)

---

- [`#2593`](https://github.com/oven-sh/bun/pull/2593)
- Implemented support for TypeScript 5.0 syntax by [@Jarred-Sumner](https://github.com/Jarred-Sumner)

---

- [`#2652`](https://github.com/oven-sh/bun/pull/2652)
- Improved performance of `crypto.createHash()` by [@paperclover](https://github.com/paperclover)

---

- [`#2661`](https://github.com/oven-sh/bun/pull/2661)
- Fixed a bug where `expect().toBeFalsy()` did not increment assertions by [@will-richards-ii](https://github.com/will-richards-ii)

---

- [`#2673`](https://github.com/oven-sh/bun/pull/2673)
- Implemented support for `axios` by [@Jarred-Sumner](https://github.com/Jarred-Sumner)

---

- [`9e1745e`](https://github.com/oven-sh/bun/commit/9e1745ee1f5844e6ab89135e776552d2ad1ad684)
- Fixed a bug with `path.dirname()` would return the wrong path for the root by [@Jarred-Sumner](https://github.com/Jarred-Sumner)

---

- [`#2728`](https://github.com/oven-sh/bun/pull/2728)
- Fixed `bun add <github>` by [@alexlamsl](https://github.com/alexlamsl)

---

- [`3c4f092`](https://github.com/oven-sh/bun/commit/3c4f0920b95cfffc52d13cb0211701ca55211164)
- remove by [@Jarred-Sumner](https://github.com/Jarred-Sumner)

---

- [`5353d41`](https://github.com/oven-sh/bun/commit/5353d4101493632cb25d0cdddfef94f62bc5902d)
- Fixed incorrect value for modulo with negative operands by [@Jarred-Sumner](https://github.com/Jarred-Sumner)

---

- [`#2748`](https://github.com/oven-sh/bun/pull/2748)
- Fixed crash with invalid JavaScript by [@Jarred-Sumner](https://github.com/Jarred-Sumner)

---

- [`#2759`](https://github.com/oven-sh/bun/pull/2759)
- Improved performance of `open()` and `writeFileSync()` by [@Jarred-Sumner](https://github.com/Jarred-Sumner)

---

- [`#2761`](https://github.com/oven-sh/bun/pull/2761)
- Fixed incorrect output from `Hash.copy()` by [@silversquirl](https://github.com/silversquirl)

---

- [`396416a`](https://github.com/oven-sh/bun/commit/396416a91fed5166f3c4e9c340a3f2af5367bb78)
- Fixed crash from invalid input in `fetch()` by [@Jarred-Sumner](https://github.com/Jarred-Sumner)

---

- [`#2780`](https://github.com/oven-sh/bun/pull/2780)
- Fixed a bug with repeated `bun install` of a GitHub dependency by [@alexlamsl](https://github.com/alexlamsl)

---

- [`#2781`](https://github.com/oven-sh/bun/pull/2781)
- Fixed a bug where `devDependencies` did not resolve from a local dependency by [@alexlamsl](https://github.com/alexlamsl)

---

- [`#2754`](https://github.com/oven-sh/bun/pull/2754)
- Implemented `expect().toBeEven()` and `expect().toBeOdd()` by [@will-richards-ii](https://github.com/will-richards-ii)

---

- [`c43c1b5`](https://github.com/oven-sh/bun/commit/c43c1b50fffece35c1507f18758df6b450cc57c9)
- Implemented `ClientRequest.setNoDelay()` by [@Electroid](https://github.com/Electroid)

---

- [`f95a81e`](https://github.com/oven-sh/bun/commit/f95a81e05de50debf60771c46111d115334afe96)
- Fixed a crash in `napi_create_external_buffer` by [@Jarred-Sumner](https://github.com/Jarred-Sumner)

---

- [`c7c5dc1`](https://github.com/oven-sh/bun/commit/c7c5dc14384f81a2d245870d2848c0512193690d)
- Implemented `BunFile.name` by [@Jarred-Sumner](https://github.com/Jarred-Sumner)

---

- [`#2834`](https://github.com/oven-sh/bun/pull/2834)
- Fixed a bug where `bun install --cwd` was not working correctly by [@alexlamsl](https://github.com/alexlamsl)

---

- [`#2841`](https://github.com/oven-sh/bun/pull/2841)
- Changed `bun add` to ignore invalid workspaces by [@alexlamsl](https://github.com/alexlamsl)

---

- [`#2843`](https://github.com/oven-sh/bun/pull/2843)
- Fixed a crash during `WebSocket.close()` by [@cirospaciari](https://github.com/cirospaciari)

---

- [`#2842`](https://github.com/oven-sh/bun/pull/2842)
- Fixed `fetch.bind` is not a function by [@cirospaciari](https://github.com/cirospaciari)

---

- [`#2845`](https://github.com/oven-sh/bun/pull/2845)
- Implemented `fetch({ redirect: "error" })` by [@cirospaciari](https://github.com/cirospaciari)

---

- [`#2836`](https://github.com/oven-sh/bun/pull/2836)
- Implemented `describe.skip()` by [@blackmann](https://github.com/blackmann)

---

- [`5ffee94`](https://github.com/oven-sh/bun/commit/5ffee9477cc856d975b6ac8577f25396b55e8403)
- Added timings to each test in `bun test` by [@Jarred-Sumner](https://github.com/Jarred-Sumner)

---

- [`#2846`](https://github.com/oven-sh/bun/pull/2846)
- Implemented `dns.lookup({ all: true })` by [@cirospaciari](https://github.com/cirospaciari)

---

- [`#2851`](https://github.com/oven-sh/bun/pull/2851)
- Fixed suprious errors with `mkdtemp()` and `mktempSync()` by [@cirospaciari](https://github.com/cirospaciari)

---

- [`5c08200`](https://github.com/oven-sh/bun/commit/5c08200b1845fad5a97c864a63c3f03424c15fab)
- Changed `node:http` to handle errors better from `fetch()` by [@Jarred-Sumner](https://github.com/Jarred-Sumner)

---

- [`#2850`](https://github.com/oven-sh/bun/pull/2850)
- Fixed `Bun.spawn()` with a large stdout by [@cirospaciari](https://github.com/cirospaciari)

---

- [`#2869`](https://github.com/oven-sh/bun/pull/2869)
- Fixed `node:path` for Windows by [@paperclover](https://github.com/paperclover)

---

- [`#2879`](https://github.com/oven-sh/bun/pull/2879)
- Implemented support for generating standalone Bun executables by [@Jarred-Sumner](https://github.com/Jarred-Sumner)

---

- [`#2866`](https://github.com/oven-sh/bun/pull/2866)
- Implemented `Uint8Array` support for `Bun.spawn()` stdout by [@cirospaciari](https://github.com/cirospaciari)

---

- [`#2881`](https://github.com/oven-sh/bun/pull/2881)
- Fixed bug where `Request.url` was incorrect by [@Jarred-Sumner](https://github.com/Jarred-Sumner)

---

{% /table %}

## Contributors

And finally, thank you to all the contributors from the community that helped improve Bun this release: [@privatenumber](https://github.com/privatenumber), [@Lawlzer](https://github.com/Lawlzer), [@jakeboone02](https://github.com/jakeboone02), [@zhongweiy](https://github.com/zhongweiy), [@xHyroM](https://github.com/xHyroM), [@rmorey](https://github.com/rmorey), [@marktani](https://github.com/marktani), [@Kruithne](https://github.com/Kruithne), [@will-richards-ii](https://github.com/will-richards-ii), [@simon04](https://github.com/simon04), [@alexlamsl](https://github.com/alexlamsl), [@flakey5](https://github.com/flakey5), [@MaanuVazquez](https://github.com/MaanuVazquez), [@Plecra](https://github.com/Plecra), [@silversquirl](https://github.com/silversquirl), [@beeburrt](https://github.com/beeburrt), [@aquapi](https://github.com/aquapi), [@blackmann](https://github.com/blackmann), [@Fire-The-Fox](https://github.com/Fire-The-Fox)