X_TEST_THROW_NOT_THROWN

expect(fn).toThrow(…) is given a callback that returns an error instead of throwing one

bun's synchronous toThrow passes on a returned Error — expect(() => new Boom('x')).toThrow(Boom) is green, in the bare, class and string-matcher forms alike — so the assertion cannot fail. This repo exports 196 functions that return an error beside a matching set that throws, and expect(() => sendFailed(…)) is the shape. A returned non-error is reported correctly by bun, and rejects.toThrow is unaffected. Only certain shapes are reported: an error construction, or a call to a function this repo declares as returning one

wrap it in a throw at the site the finding names — expect(() => { throw <expr>; }).toThrow(…) — or assert the value directly with expect(<expr>).toBeInstanceOf(…)