@zgeoff/bun-test-extended

jest-extended matchers for bun test, with working failure messages and bun-aware types.

Plain expect.extend(matchers) breaks on bun: jest-extended destructures this.utils, bun's native utils are brand-checked, so every failing assertion crashes with Expected this to be instanceof ExpectMatcherUtils instead of printing a diff. This package wraps each matcher in an adapter that supplies the real jest-matcher-utils and keeps this.equals bound, then registers the lot.

Usage

# bunfig.toml — registers the matchers in every test file
[test]
preload = ["@zgeoff/bun-test-extended"]

// tsconfig.json — loads the matcher types
{ "compilerOptions": { "types": ["bun", "@zgeoff/bun-test-extended"] } }

test('it works', () => {
  expect(['a', 'b']).toIncludeAllMembers(['b']);
  expect({ n: 4 }).toEqual({ n: expect.toBeEven() });
});

Types

• Augments bun:test with only the matchers bun doesn't already declare — no conflicts with builtins, and unknown matcher names fail typecheck (upstream's own types would let typos through).
• toResolve/toReject return Promise<void> — un-awaited use is visible.
• Asymmetric matchers (expect.toBeOneOf(…) inside toEqual) fit any value position.

Gaps

expect.pass/expect.fail are unimplemented upstream and excluded here.