Log dependencies that are potentially duplicated in yarn.lock

yarn-lock-check.js

const readline = require('readline');
const fs = require('fs');

const file = fs.createReadStream('yarn.lock');

const rl = readline.createInterface(file);

let lastPkg, lastVer, lastLine, currPkg, currVer, currLine;
const re = /^"?(@?[^@]+)/;
rl.on('line', (line) => {
  if (currPkg && !currVer) {
    currVer = line.split(' ').pop();

    if (lastPkg === currPkg && lastVer[1] === currVer[1]) {
      console.log(currPkg);
      console.log(`  ${lastVer} ${lastLine}`);
      console.log(`  ${currVer} ${currLine}`);
    }
    return;
  }
  if (!line[0] || line[0] === ' ') return;
  lastLine = currLine;
  lastPkg = currPkg;
  lastVer = currVer;
  currVer = null;
  currLine = line;
  currPkg = re.exec(line)[1];
});