npm machette - find unused dependencies by grepping the dependency name

machette.js

// pnpm -r -c exec 'node /path/to/machette.js'

const util = require('util');
const exec = util.promisify(require('child_process').exec);
const process = require('process');
const path = require('path');

async function main() {
  const cwd = process.cwd();

  const packageJsonPath = path.join(cwd, "package.json");
  const packageJson = require(packageJsonPath);
  if (packageJson.dependencies === undefined) {
    return
  }
  const deps = Object.keys(packageJson.dependencies);
  const scripts = packageJson.scripts || {};

  const results = [];
  const tasks = deps
    .filter((dep) => !dep.startsWith('@types'))
    .filter((dep) => !Object.values(scripts).some((s) => s.includes(dep)))
    .map(async (dep) => {
      try {
        const { stdout } = await exec(`git grep ${dep} | grep -e import -e require`, {maxBuffer: 1024 * 1000})
        if (stdout.length === 0) {
          results.push(dep);
        }
      } catch (e) {
        results.push(dep);
      }
    });

  await Promise.all(tasks);

  if (results.length > 0) {
    console.log('-------------')
    console.log('cwd:', cwd);
    console.log(results)
  }
}

main()