---
title: Bun v0.6.6
description: Lots of improvements to `bun test`, including Github Actions support, `bun test --only`, `test.if()`, `describe.skip()`, and more matchers
date: "2023-05-31T17:56:51+00:00"
author: ashcon
draft: false
---
{% callout %}
We're hiring C/C++ and Zig engineers to build the future of JavaScript! [Join our team →](/careers)
{% /callout %}
We've been releasing a lot of changes to Bun recently, here's a recap in case you missed it:
- [`v0.6.0`](/blog/bun-bundler) - Introducing `bun build`, Bun's new JavaScript bundler.
- [`v0.6.2`](/blog/bun-v0.6.2) - Performance boosts: 20% faster `JSON.parse`, up to 2x faster `Proxy` and `arguments`.
- [`v0.6.3`](/blog/bun-v0.6.3) - Implemented `node:vm`, lots of fixes to `node:http` and `node:tls`.
- [`v0.6.4`](/blog/bun-v0.6.4) - Implemented `require.cache`, `process.env.TZ`, and 80% faster `bun test`.
- [`v0.6.5`](/blog/bun-v0.6.5) - Native support for CommonJS modules (_previously, Bun did CJS to ESM transpilation_), Vue support
Now, we're releasing Bun v0.6.6, with significant improvements to `bun test`, including Github Actions support, support for `test.only()`, `test.if()`, `describe.skip()`, and 15+ more `expect()` matchers; also streaming file uploads using `fetch()`.
To install Bun:
{% codetabs %}
```sh#curl
$ curl -fsSL https://bun.sh/install | bash
```
```sh#npm
$ npm install -g bun
```
```sh#brew
$ brew tap oven-sh/bun
$ brew install bun
```
```sh#docker
$ docker pull oven/bun
$ docker run --rm --init --ulimit memlock=-1:-1 oven/bun
```
{% /codetabs %}
{% raw %}
{% /raw %}
To upgrade Bun:
```sh
$ bun upgrade
```
## `bun test` in Github Actions
Bun will now detect if `bun test` is running in a Github Action.
First, it will collapse tests by file in the logs output to make it easier to read.
Next, it will annotate errors with its name, message, and stack trace.
You also don't need to install any plugins or extensions for this to work. Bun will read the `GITHUB_ACTIONS` environment variable and check if it's set to `true`.
## `bun test --only`
You can now specify `--only` to only run tests that are marked with `test.only()` or `describe.only()`. This is useful when you want to debug a specific test in a file.
```js
import { test, describe } from "bun:test";
describe.only("describe #1", () => {
test("test #1", () => {
// runs
});
test.skip("test #2", () => {
// does not run
});
});
test("test #3", () => {
// does not run
});
test.only("test #4", () => {
// runs
});
```
## `bun test --todo`
In addition to `test.skip()`, you can also define a test using `test.todo()` or `describe.todo()`. By default, these tests are not run, _unless_ you specify `--todo`. This is useful for tests that are not yet implemented or are broken or flaky in some way.
```js
import { test } from "bun:test";
test("test #1", () => {
// runs
});
test.todo("test #2"); // never runs
test.todo("test #3", () => {
// only runs if --todo is passed
});
```
## `test.if()` and `describe.if()`
You can now specify a conditional test, based on a boolean value. You can also use `test.skipIf()` if you want the inverse behaviour.
So instead of doing this:
```js
import { it } from "bun:test";
const macOS = process.arch === "darwin";
const test = macOS ? test : test.skip;
```
You can just do this:
```js
import { test, describe } from "bun:test";
const macOS = process.arch === "darwin";
test.if(macOS)("test #1", () => {
// runs if macOS
});
test.skipIf(macOS)("test #2", () => {
// skips if macOS
});
describe.if(macOS)("describe #1", () => {
test("test #3", () => {
// runs if macOS
});
});
```
## Timeouts in `test()`
In Jest, you can specify a third argument to `test()` as a timeout value in milliseconds. In Vitest, you can also specify an object, with a `timeout` property. In Bun, you can now do both.
```js
import { test } from "bun:test";
import { sleep } from "bun";
test("timeout #1", async () => {
await sleep(10);
}, 1);
test(
"timeout #2",
async () => {
await sleep(10);
},
{ timeout: 1 },
);
```
The default timeout is 5000, you can change the default by using `--timeout`.
```sh
$ bun test --timeout 1000 # 1 second
```
## New matchers for `expect()`
We've added a lot of new matchers to `expect()`, with more coming soon. Most of these are supported by the `jest-extended` matchers.
```js
import { test, expect } from "bun:test";
test("new matchers", () => {
expect(null).toBeNil();
expect(true).toBeBoolean();
expect(3.14).toBePositive();
expect(314).toBeInteger();
expect(3.1).toBeWithin(3, 3.14);
expect(() => {}).toBeFunction();
expect(new Date()).toBeDate();
expect("bunny").toInclude("bun");
expect("buntime").toStartWith("bun");
});
```
- [`toBeNil()`](https://jest-extended.jestcommunity.dev/docs/matchers/tobenil)
- [`toBeBoolean()`](https://jest-extended.jestcommunity.dev/docs/matchers/Boolean#tobeboolean)
- [`toBeTrue()`](https://jest-extended.jestcommunity.dev/docs/matchers/Boolean#tobetrue)
- [`toBeFalse()`](https://jest-extended.jestcommunity.dev/docs/matchers/Boolean#tobefalse)
- [`toBeNumber()`](https://jest-extended.jestcommunity.dev/docs/matchers/Number)
- [`toBeInteger()`](https://jest-extended.jestcommunity.dev/docs/matchers/Number#tobeinteger)
- [`toBeFinite()`](https://jest-extended.jestcommunity.dev/docs/matchers/Number#tobefinite)
- [`toBePositive()`](https://jest-extended.jestcommunity.dev/docs/matchers/Number#tobepositive)
- [`toBeNegative()`](https://jest-extended.jestcommunity.dev/docs/matchers/Number#tobenegative)
- [`toBeWithin(start, end)`](https://jest-extended.jestcommunity.dev/docs/matchers/Number#tobewithinstart-end)
- [`toBeSymbol()`](https://jest-extended.jestcommunity.dev/docs/matchers/Symbol)
- [`toBeFunction()`](https://jest-extended.jestcommunity.dev/docs/matchers/Function)
- [`toBeDate()`](https://jest-extended.jestcommunity.dev/docs/matchers/Date)
- [`toBeString()`](https://jest-extended.jestcommunity.dev/docs/matchers/String#tobestring)
- [`toInclude()`](https://jest-extended.jestcommunity.dev/docs/matchers/String#toincludesubstring)
- [`toStartWith()`](https://jest-extended.jestcommunity.dev/docs/matchers/String#tostartwithprefix)
- [`toEndWith()`](https://jest-extended.jestcommunity.dev/docs/matchers/String#toendwithsuffix)
## Streaming `fetch()` file uploads
You can now do a streaming upload a file using `fetch()` in Bun
```js
import { file } from "bun";
await fetch("https://example.com/", {
method: "POST",
body: file("avatar.png"),
});
```
You can also do this with a `FormData` upload.
```js
import { file } from "bun";
const formData = new FormData();
formData.set("attachment", file("data.csv"));
await fetch("https://example.com/", {
method: "POST",
body: formData,
});
```
When a large file is sent over HTTP, Bun automatically makes it faster using the `sendfile()` system call.
{% raw %}
{% /raw %}
## Bug fixes
We also made various bug fixes.
Regressions in 0.6.5 from the CommonJS rewrite:
- `--watch` and `--hot` were broken when importing CommonJS modules, this is now fixed.
- Fixed a bug with `Object.defineProperty(module, "exports", { get })`, which fixes packages like `supports-color`.
More bugfixes:
- A bundler transform would incorrectly rewrite `module.exports` to `exports` when used in UMD modules, this is now fixed.
- Fixed a bug with `path.parse()` that did not resolve certain paths properly, thanks to [@cirospaciari](https://github.com/cirospaciari).
- Fixed a crash with `expect(null).toHaveProperty()`.
- Fixed a crash that could occur when an error is thrown in Bun.listen() or Bun.connect() callbacks (or `node:net` or `node:tls`)
- Fixed a bug where Bun.spawn() would attempt to chdir to an empty string
- Fixed a mistranspilation involving optional chaining with computed properties in multiple levels of nesting thanks to [@dylan-conway](https://github.com/dylan-conway)
More things:
- Added the `--no-macros` flag and disabled macros in the `node_modules` folder
- Added the `macro` package.json export condition