v2.8.1

Patch Changes

• 2a0bd87: Refactored the core recurrence-rule implementation to share query/caching logic across RRule and RRuleSet, while also fixing a few correctness/performance issues in iteration and caching behavior.

  Bug Fixes

  • Fixed removeFilteredDays accumulation bug

    • Was overwriting filtered on each iteration instead of accumulating. Only the last day's filter status was returned, causing sub-daily frequencies to
      potentially skip the wrong number of days when earlier days in the set were filtered out.

  • Fixed RRuleSet.clone() inverted noCache

    • Changed new RRuleSet(!!this._cache) to new RRuleSet(!this._cache). The constructor param is noCache, so the old code was enabling cache on uncached
      sets and vice versa.

  • Removed dead lno1wkst = 0 assignment

    • The value was assigned inside an if block but never read afterward. Changed declaration from let to const.

  Architecture

  • Extracted RRuleBase abstract class
    • Moved shared query methods (all, between, before, after, count) and caching logic into RRuleBase.
    • RRule extends RRuleBase — keeps options, _iter, toString, toText, NLP methods.
    • RRuleSet extends RRuleBase — no longer extends RRule or calls super({}, noCache) with fake empty options.
    • Exported RRuleBase from src/index.ts so consumers can use instanceof RRuleBase for any rule-like object.
    • Updated test utilities to use RRuleBase for shared type checking.

  Performance

  • rrules()/exrules() — eliminated serialize+reparse

    • Was: this._rrule.map((e) => rrulestr(e.toString())) — serializes to RFC string then re-parses.
    • Now: this._rrule.map((e) => e.clone()) — direct clone, removed the rrulestr import entirely.

  • _addRule/_addDate — eliminated O(n) array allocation

    • Was: collection.map(String).includes(String(rrule)) — allocates a new array on every call.
    • Now: collection.some((r) => String(r) === str) — short-circuits without allocating.
    • Same pattern for _addDate: .some((d) => d.getTime() === time) instead of .map(Number).includes(Number(date)).

  • Added cache size bounds (src/cache.ts)

    • Added MAX_CACHE_SIZE = 64 constant.
    • before/after/between caches now evict the oldest entry (FIFO) when the limit is reached, preventing unbounded memory growth on long-lived instances.

  Type Safety

  • Narrowed bynweekday to tuple type (src/types.ts)

    • Changed bynweekday: number[][] | null to bynweekday: [number, number][] | null in ParsedOptions, enabling safe destructuring without ! assertions in
      monthinfo.ts and parseoptions.ts.

  • Narrowed toText options to ParsedOptions (src/nlp/totext.ts)

    • Changed private options: Partial to private options: ParsedOptions, removing ~40 ! assertions on this.options.freq, this.options.interval,
      this.options.bymonthday, etc.

  • Added explicit return types to dateutil helpers (src/dateutil.ts)

    • getWeekday(): number, getMonthDays(): number, monthRange(): [number, number].
    • Eliminated downstream ! assertions in datetime.ts and yearinfo.ts where these return values were used.

  • Added explicit return type to extractName (src/rrulestr.ts)

    • Typed as { name: string; value: string } with default destructuring values, removing ! assertions on name and value.

  • Added default destructuring values in parseString (src/parsestring.ts)

    • const [key = '', value = ''] = attr.split('=') and similar patterns, eliminating undefined-possibility assertions.

  • Fixed Cache.all type (src/cache.ts)

    • Was: Date[] | Partial | false — Partial was never stored as all.
    • Now: Date[] | false.

  • Clarified cache miss check (src/cache.ts)

    • Changed if (!cached && this.all) to if (cached === false && this.all) — makes intent explicit for "not in cache" vs "cached as null".

  Code Cleanup

  Converted C-style loops to for...of across 7 files

  • monthinfo.ts, optionstostring.ts, parseoptions.ts, yearinfo.ts, iterset.ts, iter/index.ts, iter/poslist.ts — eliminates uncertain array-index !
    assertions.

  Removed dead code (src/iter/index.ts)

  • Deleted redundant interval === 0 check (already checked at function entry).

  Removed redundant instanceof runtime guards (src/rruleset.ts)

  • _addRule had if (!(rrule instanceof RRule)) and _addDate had if (!(date instanceof Date)) — parameters are already typed, so these were always true.
    Removed guards and corresponding tests.

  Fixed test parse() null safety (test/lib/utils.ts)

  • Added null guard for regex match result before destructuring. Simplified with Number() instead of intermediate variables.

  Features

  • toText() now includes start date (src/nlp/totext.ts)
    • When dtstart is explicitly set in rule options, toText() appends , starting [formatted date] to the output.
    • Example: "every 2 months on the 15th, starting February 18, 2026".
    • Rules without an explicit dtstart are unaffected.

  Tooling

  • Updated README (README.md)
    • Fixed stale badges, broken code examples, byeaster docs, wkst typo, LICENCE/LICENSE link, dev tooling (Biome), and documented new toText() starting
      date behavior.