Key learnings on publishing packages to npm

How to publish a package to npm?

There are a few steps to publish a package to npm:

• Make sure the package code is in a Git repository
• Create an account on npmjs.com if you don’t already have one
• From the package directory, run npm init to initialize npm configuration
• Update package.json with metadata like name, version, description etc
• Run npm publish to publish the package to npm
• Use npm version patch/minor/major to bump version before re-publishing updates

What is the value of Lerna in managing monorepos?

Lerna provides commands to:

• Manage dependencies between packages in a monorepo
• Publish packages independently with a single command
• Create/remove packages within a monorepo
• Run scripts on all packages like test, build etc

So it simplifies publishing and versioning of packages in a monorepo.

How does yarn workspace help in managing dependencies in Lerna?

Yarn workspace manages dependencies intelligently across all packages in a monorepo. It:

• Installs all dependencies in a single root node_modules folder
• Allows cross-dependency linking between packages
• Avoids duplication of dependencies across packages

This avoids the need for Lerna’s --hoist flag and improves dependency management.

How to build UMD packages for publishing?

To build UMD packages for publishing to npm:

• Set module and main fields in package.json pointing to ES module and CommonJS builds
• Add unpkg field pointing to UMD build
• Build UMD version with webpack adding UMD library export
• Output UMD build to dist/index.umd.js

The UMD build can then be consumed via script tag in browsers.

How does Lerna versioning and publishing work?

• lerna version bumps version based on semver keywords in commit message
• lerna publish publishes changed packages to npm
• lerna publish from-package publishes only specified package
• Use --independent flag for independent versioning

Lerna handles versioning and publishing of multiple packages in a monorepo.

How can Bit help in managing and publishing components?

Bit allows:

• Isolating components into re-usable units with encapsulated dependencies
• Organizing components into Scopes with search and versioning
• Publishing components to Bit’s npm registry
• Importing components into projects from Bit registry

Bit provides an alternative lightweight approach to monorepos for component management.

References

ref:

• https://docs.npmjs.com/creating-and-publishing-private-packages
• https://github.com/lerna/lerna
• https://bit.dev