Capture input in the child process after spawn in node

I'm working on a small cli tool that can automatically deploy Google Home actions based on the projects that are setup in a directory.

Basically my script checks the directories and then asks which project to deploy. The actual command that should run is coming from Google's cli gactions

To run it with arguments I setup a spawned process in my node-script:

const { spawn } = require('child_process')
const child = spawn('./gactions', [
    'update',
    '--action-package',
    '<PATH-TO-PACKAGE>',
    '--project',
    '<PROJECT-NAME>'
])

child.stdout.on('data', data => {
    console.log(data)
}

However, the first time a project is deployed, the gactions cli will prompt for an authorization code. Running the code above, I can actually see the prompt, but the script won't proceed when actually entering that code.

I guess there must be some way in the child process to capture that input? Or isn't this possible at all?

Solution

Simply pipe all standard input from the parent process to the child and all output from the child to the parent.

The code below is a full wrapper around any shell command, with input/output/error redirection:

const { spawn } = require('child_process');
var child = spawn(command, args);

child.stdout.pipe(process.stdout);
child.stderr.pipe(process.stderr);
process.stdin.pipe(child.stdin);

child.on('exit', () => process.exit())

Note that if you pipe stdout you don't need handle the data event anymore.