[hoanle0126]

Checklist

• run npm run test and npm run benchmark
• tests and/or benchmarks are included
• documentation is changed or added
• commit message and code follows the Developer's Certification of Origin
  and the Code of conduct

Description

Fixes #469

LocalStore.prototype.incr previously passed the mutable current object stored in this.lru directly to cb(null, current). Because applyRateLimit awaits the promise wrapping store.incr(...), concurrent or pipelined requests arriving in the same event-loop turn mutate ++current.current on the shared reference before any request resumes after await. When a pipelined batch exceeds max, all requests in the batch read the final mutated res.current value and fail with 429 instead of only the requests that exceed max.

This change returns a snapshot { current: current.current, ttl: current.ttl } from LocalStore.prototype.incr (consistent with LocalStore.prototype.read and RedisStore.prototype.incr) and adds a regression test for #469.

[mcollina]

lgtm

[Tony133]

lgtm