Question

I am versioning a library with SemVer, and distibuting it with NuGet.

I am making some bugfixes and performance-related changes that do not modify the public API of the library in any way, but do involve adding a new dependency.

Usually I’d just increment the patch or minor versions when bugfixing or changing private code. Is this still appropriate when adding a new dependency as well? Or should I increment the major version, despite there being no changes in the public API? Are there any concrete guidelines for issues like this?

Answer 1

You almost certainly should use a minor version change.

The Wikipedia article on version numbers states:

In principle, in subsequent releases, the major number is increased when there are significant jumps in functionality, the minor number is incremented when only minor features or significant fixes have been added, and the revision number is incremented when minor bugs are fixed.

I would consider a dependency a minor feature. Also, performance is a minor feature unless it is both a substantial limitation that the users encounter and you are making a large improvement.