1- ESLint - Integrates ESLint JavaScript into VS Code.
2- CodeMetrics - Computes complexity in TypeScript / JavaScript files.
3- SonarLint - SonarLint is an IDE extension that helps you detect and fix quality issues as you write code in JavaScript, TypeScript, Python, Java, HTML and PHP.
To enable Sonar lint, you have to install java runtime environment(jre), which it will ask to download it when it has been installed.
You can use Tech Debt Metrics as a complement to CodeMetrics metric checker(But it is too heavy!).
Recommended Extension pack
ZPack is An Opinionated collection of the best and most used extensions for Web Developers in VSCode which has Better Developer Experience(DX) and load time in Mind.