Example of finding unused npm packages using git grep

x.ts

import { exec } from 'node:child_process';

import packages from './package.json';

for (const pkg in packages.dependencies) {
  exec(`"/usr/local/bin/git" grep ${pkg} src`, (err, stdout, stderr) => {
    if (err) {
      console.log(`${pkg} can be removed`);
    }
  });
}
console.log('done');