Building

• npm run build_release Will run the lint (failing if it gives any warnings), build it, and deploy with np

Doing it in stages

• npm run pkglint ensures the code and package set up is optimal
• npm run build generates the package in ./dist (which package.json tells NPM about in fields such as 'export')
• np updates the package version, checks everything is OK, and tags it as a git release for NPM, and pushes to NPM.

FAQ

Want to use GitHub Actions to publish to NPM?

• Change np to prevent auto publishing, by using the --no-publish flag (see https://github.com/sindresorhus/np)
• Set up a GitHub Action (see https://docs.github.com/en/actions/publishing-packages/publishing-nodejs-packages)

What is responsible for the building? Babel?

• tsup is responsible (I believe uses esbuild under the hood)
• Babel is only installed to make Jest work

# Troubleshooting

Testing code that imports ESM modules

In jest.config.js

• Add the package to transformIgnorePatterns
• If the package uses import.meta.url (Jest will throw an error if it does and you've not set this up), make sure you've installed and set up https://github.com/javiertury/babel-plugin-transform-import-meta. FYI this package now has it installed and set up in babel.config.js.

"You do not have permission to publish" / "You do not have write permissions required to publish this package."

If the message comes from np, run npm publish for a more detailed error message.

There are a few reasons:

• Are you logged in? Run npm whoami (and npm login if needed)
• Did you verify the email address for your NPM account?
• Is it a duplicate package name? If so, consider scoping

History

The build process was heavily inspired by https://mikeesto.com/posts/publishing-npm-package/. Notably:

• tsup builds commonjs and esm modules into ./dist, using the config in npm run build
• npm run pkglint runs the linter for the Npm Package, to give suggestions that ensure max compatibility. See https://publint.dev.
• Opted to use https://github.com/sindresorhus/np to build a publishable release.

https://github.com/frehner/modern-guide-to-packaging-js-library is a very helpful resource for understanding the options.

I switched from 'objects' to a scoped package, @andyrmitchell/objects

• Note my GitHub is @andymitchell, but NPM is @andyrmitchell (r in the middle). It has to be andyrmitchell for permission on NPM.

• When you scope something by changing the name to use @, it switches to publishing privately.

  • Therefore in package.json I set publishConfig.access to 'public'

• Had to install Babel to get jest to correctly work with ES Modules (like lodash-es, dot-prop). It feels like a lot of cruft just for that.