bun-test

Bun ships with a fast, built-in, Jest-compatible test runner. Tests are executed with the Bun runtime, and support the following features.

• TypeScript and JSX
• Lifecycle hooks
• Snapshot testing
• UI & DOM testing
• Watch mode with --watch
• Script pre-loading with --preload

{% callout %} Bun aims for compatibility with Jest, but not everything is implemented. To track compatibility, see this tracking issue. {% /callout %}

Run tests

$ bun test

Tests are written in JavaScript or TypeScript with a Jest-like API. Refer to Writing tests for full documentation.

import { expect, test } from "bun:test";

test("2 + 2", () => {
  expect(2 + 2).toBe(4);
});

The runner recursively searches the working directory for files that match the following patterns:

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

You can filter the set of test files to run by passing additional positional arguments to bun test. Any test file with a path that matches one of the filters will run. Commonly, these filters will be file or directory names; glob patterns are not yet supported.

$ bun test <filter> <filter> ...

To filter by test name, use the -t/--test-name-pattern flag.

# run all tests or test suites with "addition" in the name
$ bun test --test-name-pattern addition

To run a specific file in the test runner, make sure the path starts with ./ or / to distinguish it from a filter name.

$ bun test ./test/specific-file.test.ts

The test runner runs all tests in a single process. It loads all --preload scripts (see Lifecycle for details), then runs all tests. If a test fails, the test runner will exit with a non-zero exit code.

CI/CD integration

bun test supports a variety of CI/CD integrations.

GitHub Actions