npm run: Execute package.json Scripts

npm run is how CI invokes your build, test, and lint scripts.

Scripts in package.json are the contract between your repo and CI. npm run executes them with the local node_modules/.bin on PATH.

Common usage

npm run <script> - run a named script
npm run <script> -- <args> - forward args
npm run - list available scripts
--if-present - do not fail if missing

Example in CI

Forward a flag to the underlying tool.

shell

npm run test -- --coverage

In CI

A non-zero script exit fails the job. missing script errors mean the script name is not in package.json. Use --if-present for optional steps across repos.

Key takeaways

Use -- to forward args to the tool.
Non-zero exit fails the CI job.
--if-present skips missing scripts safely.