NPM vs Yarn

NPM (Node Package Manager)

• Default package manager for node
• Uses semantic versioning
  • major.minor.patch e.g. 1.2.3
  • patch versions are bugfixes that don’t break anything
  • minor versions add functionality but don’t break anything
  • major versions may have breaking changes
• Installs packages sequentially which can be slow
• NPM 5 added the package-lock.json file
  • Introduced to prevent the scenario where two people who install deps might get different versions
  • Specifies the exact version of the installed package
  • Should be committed to SC to allow the exact history of node_modules to be tracked

Yarn

• Introduced to fix many of the issues that NPM had
  • Introduced the lock file concept
  • Was much quicker to install packages
  • Introduced package caching
  • Had logical default for installing new packages
    • NPM required –save or –save-dev flag to update package.json
• Many of these issues with NPM were remedied in version 5