npm install only if package missing or out-of-date compared to package.json
问题 I want to be able to compare my locally installed packages against my project package.json file without making a call against the npm online repo. If there is a package that is out of date based on the package.json file, then and only then will it go to the npm online repo and install the package. The reason for this is that I want to be able to update the package.json file to require a newer version of a package, commit this change to the project repo and when other developers on the team