npm tag handling

npm registries support tags, which are string aliases for package versions. You can use tags to provide an alias instead of using version numbers. For example, you have a project with multiple streams of development and you use a different tag for each stream (for example, stable, beta, dev, canary). For more information, see dist-tag on npm Docs.

By default, npm uses the latest tag to identify the current version of a package. npm install pkg (without @version or @tag specifier) installs the latest tag. Typically, projects only use the latest tag for stable release versions. Other tags are used for unstable or prerelease versions.

Editing tags with the npm client

The three npm dist-tag commands (add, rm, and ls) function the same way in CodeCatalyst package repositories as they function in the default npm registry.

npm tags and upstream repositories

When npm requests the tags for a package and versions of that package are also present in an upstream repository, CodeCatalyst merges the tags before returning them to the client. For example, a repository named R has an upstream repository named U. The following table shows the tags for a package named web-helper that's present in both repositories.

Repository	Package name	Package tags
R	web-helper	latest (alias for version 1.0.0)
U	web-helper	alpha (alias for version 1.0.1)

In this case, when the npm client fetches the tags for the web-helper package from repository R, it receives both the latest and alpha tags. The versions the tags point to won't change.

When the same tag is present on the same package in both the upstream and local repository, CodeCatalyst uses the tag that was last updated. For example, suppose that the tags on webhelper have been modified to look like the following.

Repository	Package name	Package tags	Last updated
R	web-helper	latest (alias for version 1.0.0)	January 1, 2023
U	web-helper	latest (alias for version 1.0.1)	June 1, 2023

In this case, when the npm client fetches the tags for package web-helper from repository R, the latest tag will alias the version 1.0.1 because it was updated last. This makes it easy to consume new package versions in an upstream repository that are not yet present in a local repository by running npm update.