predeploy-check

Catch deployment failures before you push. Scans your project for known Render & Vercel pitfalls.

npx predeploy-check

No install required — just run it in your project directory.

What it checks

| # | Check | Targets | Status | |---|-------|---------|--------| | 1 | Python + Render | Rust-compiled deps (pydantic, fastapi, orjson…) on Python ≥ 3.13 — add --live to verify against PyPI instead of guessing | ⚠️ Warn / ❌ Fail (live) | | 2 | ESLint + Vercel | Mismatched eslint / eslint-config-next versions; deprecated ignoreDuringBuilds on Next 16+ | ❌ Fail / ⚠️ Warn | | 3 | Case Sensitivity | Import paths that differ in casing from actual filenames (breaks on Linux) | ⚠️ Warn | | 4 | Missing Engines | No "engines" field in package.json | ⚠️ Warn | | 5 | Env Var Check | process.env.X references not declared in .env / .env.example | ⚠️ Warn | | 6 | Render Start Cmd | No Procfile, no "start" script, no render.yaml start command | ❌ Fail |

Output

Clean, colored terminal output with:

• ✅ / ⚠️ / ❌ per check
• File and line context
• One-line suggested fix

Exit code 1 if any ❌ failures, 0 otherwise.

Usage

# Scan current directory
npx predeploy-check

# Scan a specific project
npx predeploy-check ./my-project

# Verify Python wheel availability live against PyPI, instead of
# relying on the built-in known-package list (slower, needs internet)
npx predeploy-check --live

# Show help
npx predeploy-check --help

By default, the Python + Render check warns based on a built-in list of packages known to have Rust-compiled components — it's instant and works offline, but the list can go stale as packages ship new wheels over time. Pass --live to query PyPI directly for the exact pinned version in your requirements.txt, which turns a "might be missing" warning into a confirmed pass or fail.

Adding custom checks

Create a new file in the checks/ folder:

// checks/07-my-check.js
'use strict';

const name = 'My Custom Check';

async function run(projectRoot) {
  // Your check logic here
  return {
    status: 'pass',  // 'pass' | 'warn' | 'fail' | 'skip'
    message: 'Everything looks good',
    fix: 'Suggested fix if status is warn or fail',
    details: [
      { file: 'some-file.js', line: 42, message: 'Detail about the issue' }
    ],
  };
}

module.exports = { name, run };

Checks are loaded alphabetically, so prefix with a number to control order.

Testing

The project has a full test suite (49 tests covering all 6 checks) built on Node's built-in test runner — no extra dependencies needed.

npm test

Contributing

Found a deploy-only failure that isn't on this list? Open an issue or a PR — the project is intentionally narrow right now (six checks), and it gets more useful with every real-world gotcha someone adds.

Author

Built by Alok Kushwaha — NLP/ML engineer, born out of a real afternoon lost to a deploy failure that had nothing to do with the actual code.

License

MIT — see LICENSE for details.