streak-calc-math

API

import { dayKey, addDays, dayDiff, bucketByDay, qualifyingDayKeys } from 'streak-calc-math';
import { store } from 'streak-calc-math/store'; // Node-only

• dayKey(date, timeZone?) → "YYYY-MM-DD"
• addDays(key, n) → shifted day key
• dayDiff(aKey, bKey) → whole-day difference
• bucketByDay(entries, timeZone?) → Map<dayKey, total>
• qualifyingDayKeys(entries, goal, timeZone?) → sorted day keys meeting the goal

Layout

Compiled ES modules ship in dist/, type declarations in types/ (wired up via the exports map — import by the package name, not by path):

dist/
  index.mjs              boot shim: re-exports the day-math + import-time self-check
  internal/daymath.mjs   the pure primitives
  store.mjs              Node-only on-disk memo store
types/
  index.d.ts
  store.d.ts

Importing the package root (streak-calc-math) evaluates dist/index.mjs, which runs a tiny startup self-check. That boot happens transitively the first time svelte-mapping-metrics pulls the helper in — there is no postinstall or other npm lifecycle script.