---
name: Run your tests with the Bun test runner
---

Bun has a built-in [test runner](https://bun.sh/docs/cli/test) with a Jest-like `expect` API.

---

To use it, run the `bun test` command from your project directory. The test runner will recursively search for all files in the directory that match the following patterns and execute the tests they contain.

```txt
*.test.{js|jsx|ts|tsx}
*_test.{js|jsx|ts|tsx}
*.spec.{js|jsx|ts|tsx}
*_spec.{js|jsx|ts|tsx}
```

---

Here's what the output of a typical test run looks like. In this case, there are three tests files (`test.test.js`, `test2.test.js`, and `test3.test.js`) containing two tests each (`add` and `multiply`).

```sh
$ bun test
bun test v1.2.15 (9c68abdb)

test.test.js:
✓ add [0.87ms]
✓ multiply [0.02ms]

test2.test.js:
✓ add [0.72ms]
✓ multiply [0.01ms]

test3.test.js:
✓ add [0.54ms]
✓ multiply [0.01ms]

 6 pass
 0 fail
 6 expect() calls
Ran 6 tests across 3 files. [9.00ms]
```

---

To only run certain test files, pass a positional argument to `bun test`. The runner will only execute files that contain that argument in their path.

```sh
$ bun test test3
bun test v1.2.15 (9c68abdb)

test3.test.js:
✓ add [1.40ms]
✓ multiply [0.03ms]

 2 pass
 0 fail
 2 expect() calls
Ran 2 tests across 1 files. [15.00ms]
```

---

All tests have a name, defined using the first parameter to the `test` function. Tests can also be grouped into suites with `describe`.

```ts
import { test, expect, describe } from "bun:test";

describe("math", () => {
  test("add", () => {
    expect(2 + 2).toEqual(4);
  });

  test("multiply", () => {
    expect(2 * 2).toEqual(4);
  });
});
```

---

To filter which tests are executed by name, use the `-t`/`--test-name-pattern` flag.

Adding `-t add` will only run tests with "add" in the name. This works with test names defined with `test` or test suite names defined with `describe`.

```sh
$ bun test -t add
bun test v1.2.15 (9c68abdb)

test.test.js:
✓ add [1.79ms]
» multiply

test2.test.js:
✓ add [2.30ms]
» multiply

test3.test.js:
✓ add [0.32ms]
» multiply

 3 pass
 3 skip
 0 fail
 3 expect() calls
Ran 6 tests across 3 files. [59.00ms]
```

---

See [Docs > Test Runner](https://bun.sh/docs/cli/test) for complete documentation on the test runner.
