skills/bun-guides-test-update-snapshots/SKILL.md
Update snapshots in `bun test`
npx skillsauth add jarle/bun-skills Bun Update snapshots in `bun test`Install this skill globally with one command. Works with Claude Code, Cursor, and Windsurf.
3 of 9 scanners reported clean
Some scanners were skipped, did not run, or reported a non-clean status. Review each row below.
bun testBun's test runner supports Jest-style snapshot testing via .toMatchSnapshot().
import { test, expect } from "bun:test";
test("snapshot", () => {
expect({ foo: "bar" }).toMatchSnapshot();
});
The first time this test is executed, Bun will write a snapshot file to disk in a directory called __snapshots__ that lives alongside the test file.
test
├── __snapshots__
│ └── snap.test.ts.snap
└── snap.test.ts
To regenerate snapshots, use the --update-snapshots flag.
bun test --update-snapshots
test/snap.test.ts:
✓ snapshot [0.86ms]
1 pass
0 fail
snapshots: +1 added # the snapshot was regenerated
1 expect() calls
Ran 1 tests across 1 files. [102.00ms]
See Docs > Test Runner > Snapshots for complete documentation on snapshots with the Bun test runner.
development
Using TypeScript with Bun, including type definitions and compiler options
development
Learn how to write tests using Bun's Jest-compatible API with support for async tests, timeouts, and various test modifiers
testing
Learn how to use snapshot testing in Bun to save and compare output between test runs
testing
Learn about Bun test's runtime integration, environment variables, timeouts, and error handling