#217 · Backend Framework Tools Developer Tool

Node Checker

Check Node.js code for module-system conflicts, asynchronous error-handling problems, security risks, blocking APIs, environment-variable mistakes, resource cleanup issues, and version incompatibilities. Results include severity, line numbers, rule identifiers, and suggested fixes.

Developer Input

Node checker input

Node.js source code

const fs = require('fs');
import path from 'node:path';
const secret = 'sk_live_123456';
app.get('/file', (req,res) => {
  const data = fs.readFileSync(req.query.path, 'utf8');
  eval(req.query.code);
  res.send(data);
});

Runtime profile

Node version

Check security Check async and cleanup Check module compatibility Auto-run while typing

How to use this developer tool

Paste Node.js application, server, CLI, or library code.
Select a runtime profile and Node version.
Enable security, async, and module checks.
Run the checker and fix critical issues before warnings.

What this developer tool does

The checker identifies common Node.js risks using static source analysis and returns an actionable report with severity and remediation guidance.

Detect module system and runtime APIs → scan async, security, filesystem, process, and network patterns → locate issues → score overall risk.

The checker cannot evaluate runtime data flow, package vulnerabilities, or dynamic imports with compiler-level certainty.

Example

Code that mixes require and import, contains a hardcoded secret, uses eval, and reads a user-controlled path synchronously is reported with multiple high-risk findings.

Tips for better output

Never execute untrusted input.
Validate and normalize filesystem paths.
Avoid blocking fs APIs in servers.
Keep secrets in validated environment variables.

FAQ

How do I check Node.js code for security issues online?

Paste the source, enable security checks, and run the checker to detect common unsafe APIs and input-handling risks.

Can this tool detect CommonJS and ES module conflicts?

Yes. It reports mixed require/import and export/module.exports patterns.

How do I find blocking filesystem calls in Node.js?

The checker flags common synchronous fs methods that can block server workloads.

Can Node Checker detect hardcoded secrets?

It detects several common credential and token assignment patterns, but all findings require review.

Does the checker find unhandled promise errors?

It reports common Promise, async, callback, and subscribe-style patterns that may lack error handling.

Related developer tools

Node Generator Node Formatter Node Converter Node Parser

Node checks

Area	Coverage
Modules	CommonJS and ESM compatibility
Security	Injection, secrets, path handling
Async	Promises, callbacks, blocking APIs
Resources	Streams, servers, timers, handles

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