Avoid synchronous file reads in HTTP handlers

#Metadata

Rule ID

ts.security.no-fs-readfile-sync-in-handler

Severity

medium

Confidence

0.86

Languages

javascript, typescript

Presets

recommended, security, strict

Stability

stable

Applies to

block

Tags

express, filesystem, performance, rules-catalog, security

#Why it matters

Blocking disk I/O inside request handlers stalls the Node.js event loop and hurts availability under load.

#Remediation

Use `fs.promises.readFile`, streams, or preload static assets outside the hot request path.

#Repository path

The generated metadata points to critiq-rules/libs/rules/catalog/rules/typescript/ts.security.no-fs-readfile-sync-in-handler.rule.yaml.