Lint and Validate

Treat validation as part of writing the code, not a separate chore. Code is not "done" while a checker still complains.

Toolchain by ecosystem

Node.js / TypeScript

1. Style + autofix -- npm run lint, or npx eslint "<path>" --fix when there is no script
2. Type safety -- npx tsc --noEmit
3. Dependency audit -- npm audit --audit-level=high

Python

1. Lint + autofix -- ruff check "<path>" --fix (fast, covers most rules)
2. Static security -- bandit -r "<path>" -ll
3. Type safety -- mypy "<path>"

The validation loop

1. Make the edit.
2. Run the relevant checks, e.g. npm run lint && npx tsc --noEmit.
3. Read the output carefully -- look at the final summary, not just the exit code.
4. Fix what it reports and re-run. Repeat until clean. Reporting code as finished while the summary shows failures is not acceptable.

When a step fails

• Linter complains -- resolve the style or syntax problem right away; many issues autofix.
• Type check complains -- reconcile the type mismatch before moving on.
• No tooling configured -- look for .eslintrc, tsconfig.json, or pyproject.toml in the project root and propose adding the missing config rather than skipping the check.

Non-negotiable: nothing gets committed or called complete until these checks pass.

Scripts