const { performance } = require("perf_hooks"); global.expect.extend({ toBeFasterThan: async (func, target) => { const start = performance.now(); var error; try { await func(); } catch (e) { error = e.toString(); } const time = performance.now() - start; return { pass: time < target && !error, message: () => error || `${func.name} took ${time}ms of maximum ${target}`, }; }, });