How can I run a script before install a new nodejs dependecy

Question

I try using preinstall npm scripts, but it only run when I checkout the project into a new space, and run "npm i" standalone

I need a solution to run a script before the new dependency writed into package.json. It doesn't depend the type of dependency: dev or prod. All of them need to check.

For example, when a new developer join to the team, and want to add new dependency which has known vulnerability, this script stops the action before the package.json was changed, and show warning message for the developer

Answer 1

There isn't a way to do that with npm scripts. So, unless you feel like implementing one you're going to have to adjust your process. Start by identifying all the problems you're trying to address with an on-dependency-install hook.

You give the example of preventing the installation of a dependency or dependency version. That's not a problem: it's a solution you've identified for the problem. Figure out what the actual problem is, and then reevaluate your solution to see if it's really the most appropriate measure to take.

Possibly (probably) you are afraid of vulnerable code making it up to production. That's a problem definition you can work with. What possible solutions exist? You've already identified the blacklist. But not only is that not supported by your tooling, even if it were the onus is then on you to keep the blacklist up to date. Given just how quickly the Node world moves, that's enough work to keep several people employed fulltime. And that's not even getting into deploying it to your developers.

The good news is that that's not the only solution: you could establish procedural safeguards against integrating vulnerable code. If you're using a distributed VCS like Git, pull requests are right there: disable pushing commits to the master or development branch, have developers work in feature branches and submit pull requests, then review those pull requests and screen any new dependencies for vulnerabilities when they show up. If you're using something like SVN, you can use feature branches with code reviews to similar effect. Your developers get extra eyes on their code looking for vulnerabilities, optimizations, edge cases, and so forth; you don't waste time screening dependencies that nobody ever tries to integrate. And nobody has to worry about getting the latest copy of the blacklist. For this particular scenario, everybody wins with a process solution over a technical solution.

If you have other reasons for wanting to fire scripts when dependencies are installed, try working back to the root of the problem the same way. The way Node dependency management and module interactions work, you'll probably discover it's preferable to develop better process habits.

Answer 2

If you are using git, you can use pre-commit/push hooks, the result is pretty much the same, no vulnerabilities in code base.

For exemple with husky and nsp you could do something like this :

{
  "scripts": {
    "prepush": "nsp check"
  }
}