npm: install before test

The blog post discusses the issue that `npm test` does not run `npm install` automatically. It presents a solution using `npm install-test` which combines the two commands in one. Additionally, it suggests modifying the `package.json` file to include a `pretest` script that runs `npm install` before testing, or using `npm ci` before testing. The content provides practical solutions for common npm usage issues that developers may encounter.