In Dart with Pub, when should I use the "any" version constraint for a dependency?

Question

When making a package, I am often confused as to whether I should use the any constraint.

I know that for:

• library packages, I should specify clear version constraints so that users of my libraries know the version of my transitive dependencies,

• application packages, I should use any and check in my pubspec.lock lockfile so that others can run my application,

but there is a grey area for:

• applications that are meant to be extended, such as codelabs, tutorials, templates, examples, and others.

• applications that also have re-usable libraries; that is, packages that have a lib directory for common functionality that doesn't make sense to put in a separate package, but also a web directory for a full-fledged application.

---

Question: When exactly should I use the any version constraint, and when should I fully specify the version constraint for Pub packages?

Answer 1

applications that are meant to be extended, such as codelabs, tutorials, templates, examples, and others.

Since these are often going to be copy-pasted as the basis of normal application packages, I'd use the any constraint and check in a lockfile to set a good example.

applications that also have re-usable libraries; that is, packages that have a lib directory for common functionality that doesn't make sense to put in a separate package, but also a web directory for a full-fledged application.

All applications should put their code in the lib directory. The web directory should just contain the entrypoint(s). So this is just a standard application package, which should use the any constraint and check in a lockfile.