Vincent Goudard

is there a way to query node.script for installed NPM packages?

I tried to send the command `script npm ls -g` following this post on SO, but this does not seem to work.

https://stackoverflow.com/questions/17937960/how-to-list-npm-user-installed-packages

Does anyone know how to do that simply (that is, preferably, without parsing node_modules folder files manually) ?

Hi,

is there a way to query node.script for installed NPM packages?

I tried to send the command `script npm ls -g` following this post on...

nodescript-query-for-installed-packages

 installed packages? My hunch is that the command failed due to a permission issue given the 

actually I am rather after local packages, though I guess it could be useful to have a way to query global ones too.

I don't see that here, but I may be missing something ... all I have when I send this message is a dict like this:

{
	"args" : [ "ls", "--scripts-prepend-node-path=true" ],
	"status" : "completed"
}

yeah ok I get it. I assumed you were having issues with the 

 which would fails bc the Node / NPM binaries do not have the permissions to access the globally installed packages, but as your patch shows, locally this works just fine.

, which is currently not exposed to the patch. I'll file that as a FR.

In the meantime - you could write a tiny wrapper script that uses 

 and sets up the necessary communication via 

 into your patch. Should work but depending on what you are trying to achieve it might be overkill? Do you just want to check if a certain package is installed or perform more complex tasks on the dependency tree returned by 

Thanks, yes indeed, I wished the npm output would be exposed to the patch.

The general idea is to check for required packages and to run 

only if necessary on a patcher startup. Ideally, this would include package version checking.

Is there any easier way that I am missing for this purpose?

ok makes sense. Would it make sense for you to include that as part of your script, rather than a separate 

For the second you could do something like the following. Code is synchronous but can be adapted for async execution:

const { execSync } = require("child_process");

try {
  execSync("npm ls --json", { cwd: __dirname, stdio: ["ignore", "pipe", "ignore"] });
  // npm ls exited with a 0 exit code - should be all ok
} catch (err) {

  // NPM failed with a non-zero exit code - err.status
  // Given the --json flag the stdout of the error is in JSON format
  const output = JSON.parse(err.stdout.toString("utf-8").trim());

  // More info on the output is present in
  // output.problems, which is an array of strings describing the issues
  // output.error.summary which is a summary text of the issues present

  console.error(output.error.summary);
}

 might be a better match for your requirements where you'd like to ensure that the content of 

node.script query for installed packages