Comparing Fibonacci Function Performance: Sync vs. Promise vs. Effect on Bun & Mac M1 Pro

Sync: Result = 832040, Time = 4.66ms
Promise: Result = 832040, Time = 262.86ms
Effect (promise): Result = 832040, Time = 1864.52ms
Effect (sync): Result = 832040, Time = 2015.37ms

import { performance } from "perf_hooks";
import { pipe, Effect } from "effect";

// Sync Variant
const fibonacciSync = (a: number): number => {
  return a <= 1 ? a : fibonacciSync(a - 1) + fibonacciSync(a - 2);
};

// Promise Variant
const fibonacciPromise = async (a: number): Promise<number> => {
  return a <= 1
    ? a
    : (await fibonacciPromise(a - 1)) + (await fibonacciPromise(a - 2));
};

// Effect Variant
const fibonacciEffect = (a: number): Effect.Effect<number> =>
  a <= 1
    ? Effect.succeed(a)
    : pipe(
        Effect.all([fibonacciEffect(a - 1), fibonacciEffect(a - 2)]),
        Effect.map(([a, b]) => a + b)
      );

// Benchmark function
const benchmark = async (name: string, fn: () => Promise<number>) => {
  const start = performance.now();
  const result = await fn();
  const end = performance.now();
  console.log(
    `${name}: Result = ${result}, Time = ${(end - start).toFixed(2)}ms`
  );
};

const n = 30;

// Execute benchmarks
(async () => {
  await benchmark("Sync", () => Promise.resolve(fibonacciSync(n)));
  await benchmark("Promise", () => fibonacciPromise(n));
  await benchmark("Effect (promise)", () =>
    Effect.runPromise(fibonacciEffect(n))
  );
  await benchmark("Effect (sync)", () =>
    Promise.resolve(Effect.runSync(fibonacciEffect(n)))
  );
})();