@noctcore/eslint-plugin-async-safety

Async-correctness rules TypeScript can't catch: unbounded fetch, dropped AbortSignals, and shared-state / concurrency races. Flat-config only, ESLint 9+.

Install

bun add -D @noctcore/eslint-plugin-async-safety   # or npm i -D / pnpm add -D

Use

// eslint.config.js
import asyncSafety from '@noctcore/eslint-plugin-async-safety';

export default [
  asyncSafety.configs.recommended,
];

Or wire rules individually:

import asyncSafety from '@noctcore/eslint-plugin-async-safety';

export default [
  {
    plugins: { 'noctcore-async-safety': asyncSafety },
    rules: {
      'noctcore-async-safety/require-fetch-timeout': ['error', { callees: ['undici.request'] }],
      // Off until you point it at server files:
      'noctcore-async-safety/no-shared-mutable-module-state': ['error', { include: ['**/server/**'] }],
    },
  },
];

Rules

| Rule | Description | 💡 | | --- | --- | --- | | require-fetch-timeout | A fetch (or configured wrapper) call must carry a signal/timeout — an unbounded request can hang forever. | 💡 | | forward-abort-signal | A function that accepts an AbortSignal but awaits a call without forwarding it leaves that work uncancellable. | | | no-shared-mutable-module-state | A module-scoped mutable binding written from an exported async/handler function is shared across concurrent requests (opt in via include). | | | prefer-parallel-awaits | Consecutive independent awaits can run concurrently with Promise.all. | 💡 | | no-concurrent-shared-mutation | A read-modify-write of an outer binding inside a concurrent Promise.all(map(async …)) callback can lose updates. | |

recommended preset

| Rule | Severity | Notes | | --- | --- | --- | | require-fetch-timeout | error | Precise and syntactic. | | no-shared-mutable-module-state | error | Inert until you set include globs, so it ships enabled but off by default. | | forward-abort-signal | warn | Heuristic — advisory. | | prefer-parallel-awaits | warn | Heuristic — advisory suggestion. | | no-concurrent-shared-mutation | warn | Heuristic — advisory. |

The 💡 rules provide editor suggestions (not autofixes) — parallelizing awaits and adding a timeout both change runtime behavior, so they are never applied automatically.