fibonacci - API reference

API reference › @evolu/common › Schedule › fibonacci

function fibonacci(
  initial: Duration,
): Schedule<
  number &
    Brand<"NonNaN"> &
    Brand<"Finite"> &
    Brand<"Int"> &
    Brand<"NonNegative"> &
    Brand<"LessThan281474976710655"> &
    Brand<"Millis">
>;

Defined in: packages/common/src/Schedule.ts:381

Fibonacci backoff schedule.

Delays follow the Fibonacci sequence, growing more slowly than exponential:

Step 1: initial
Step 2: initial
Step 3: initial * 2
Step 4: initial * 3
Step 5: initial * 5
...

Never stops — combine with take or maxElapsed to limit.

Fibonacci growth

import { assertOk, fibonacci, testCreateDeps } from "@evolu/common";

// 100ms, 100ms, 200ms, 300ms, 500ms, ...
const step = fibonacci("100ms")(testCreateDeps());
assertOk(step(undefined), [100, 100]);
assertOk(step(undefined), [100, 100]);
assertOk(step(undefined), [200, 200]);