Measure performance

src/path.bench.ts

import { pathLength, spiralLength } from "./path.lucent";

const points = Array.from({ length: 1000 }, (_, i) => ({
  x: Math.cos(i / 10) * i,
  y: Math.sin(i / 10) * i,
}));

export default {
  objects: () => pathLength(points),
  native: () => spiralLength(1000),
};

terminal

npx lucent bench

terminal

CASE      JS         LUCENT     SPEEDUP
src/path.bench.ts
objects   54.0 µs    67.1 µs    0.8x
native    90.9 µs    7.9 µs     11.5x

per call, best of 5 rounds; desktop Hermes, so devices differ

• A *.bench.ts file next to your modules exports an object of cases: functions without arguments.
• Each case runs as your compiled module and as the same TypeScript run as JavaScript, in a desktop Hermes. The results must be equal.
• A speedup below 1x usually means the call copies more data than it computes on. Design the boundary first explains why.
• Absolute times differ on devices; the comparison carries over. For numbers on a device, time the call in the app's release build.