eslint-plugin-pgbadpatterns

ESLint rules that catch PostgreSQL transaction & connection-pooling anti-patterns — the code shapes that cause idle-in-transaction pool exhaustion and transaction-pooler (RDS Proxy / pgBouncer) breakage under load. Part of pgbadpatterns; the rules are validated against a real incident corpus (see the repo's docs/validation.md).

Scope: v1 covers transaction hygiene and connection-pooling safety — not query-speed/index tuning.

Install

npm install --save-dev eslint-plugin-pgbadpatterns

Requires ESLint 9+.

Usage (flat config — eslint.config.js)

import pgbadpatterns from 'eslint-plugin-pgbadpatterns';

export default [
  {
    plugins: { pgbadpatterns },
    rules: {
      'pgbadpatterns/no-io-in-transaction': 'error',
      'pgbadpatterns/no-session-state-on-pooled-conn': 'warn',
      'pgbadpatterns/no-passthrough-transaction': 'error',
    },
  },
];

Usage (legacy .eslintrc.*)

module.exports = {
  plugins: ['pgbadpatterns'],
  rules: {
    'pgbadpatterns/no-io-in-transaction': 'error',
    'pgbadpatterns/no-session-state-on-pooled-conn': 'warn',
    'pgbadpatterns/no-passthrough-transaction': 'error',
  },
};

Rules

| Rule | What it flags | | --- | --- | | no-io-in-transaction | An awaited network/IO call (a payment SDK, mailer, HTTP client…) inside a transaction callback — holds the pooled connection idle in transaction until the call returns. | | no-session-state-on-pooled-conn | Session-scoped SQL (SET …, pg_advisory_lock(...)) that breaks or pins a connection behind a transaction pooler. | | no-passthrough-transaction | A withTransaction(fn, em) call that passes an existing manager, so the callback joins the caller's transaction instead of opening its own. |

Type-aware rule

no-passthrough-transaction is type-aware: it needs typed linting to resolve the argument type. Configure @typescript-eslint/parser with type information (projectService: true or parserOptions.project) for it to fire. The other two rules work without type information.

License

MIT — see LICENSE.