Given `before-yarn.lock` and `after-yarn.lock`, prints the dependencies changed in a human readable list

yarn-lockfile-diff.ts

const fs = require('fs');
const yarnLockfile = require('@yarnpkg/lockfile');

function parseLockfile(filePath) {
  const file = fs.readFileSync(filePath, 'utf8');
  return yarnLockfile.parse(file).object;
}

function getVersionDifferences(beforeLockfile, afterLockfile) {
  const diffs: Record<string, { before: string, after: string }> = {};
  const allKeys = new Set<string>([
    ...Object.keys(beforeLockfile),
    ...Object.keys(afterLockfile),
  ]);

  allKeys.forEach((key) => {
    const dep = key.split("@")[0];
    const beforeVersion = beforeLockfile[key]?.vearsion;
    const afterVersion = afterLockfile[key]?.version;

    if (!diffs[dep]) {
      diffs[dep] = { before: beforeVersion, after: afterVersion };
    } else {
      if (beforeVersion) diffs[dep].before = beforeVersion;
      if (afterVersion) diffs[dep].after = afterVersion;
    }
  });

  return diffs;
}

const beforeLockfile = parseLockfile('before-yarn.lock');
const afterLockfile = parseLockfile('after-yarn.lock');

const versionDifferences = getVersionDifferences(beforeLockfile, afterLockfile);
console.log('Dependency Version Changes:\n');
Object.entries(versionDifferences)
  .filter(([_, v]) => v.before !== v.after)
  .sort(([a], [b]) => a.localeCompare(b))
  .forEach(([k, v]) => console.log(`- ${k}: ${v.before || 'none'} -> ${v.after || 'removed'}`));