How should I retrieve the latest version of a Maven project for contract testing?

Question

We're using Maven and Nexus to distribute components (Maven projects) inside our infrastructure. For the sake of the argument, let's say we have two teams: Team Foo and Team Bar; and that a component from Bar depends on a component from Foo.

Team Bar wants to write contract tests for checking if component foo behaves as expected. Those tests would run every night against the latest stable development version of project foo (git master after CI). Could Team Bar write a Maven project bar/pom.xml that depends on the latest version of foo? How can we go about doing that?

We're playing with the idea of solving this through version naming. We would always name the under development version as master-SNAPSHOT (or something) and instead of the version label going 0.1-SNAPSHOT -> 0.1 -> 0.2-SNAPSHOT -> 0.2, it would always go back to master-SNAPSHOT, like master-SNAPSHOT -> 0.1 -> master-SNAPSHOT -> 0.2. Contract testing project bar could then declare its dependency to foo as com.acme:foo:master-SNAPSHOT.

But this seems too clunky (breaks common Maven practice and stuff)... Is there a more standard practice for this kind of thing? Should we use Maven Versions Plugin? Should we inject the latest version string into the Maven project from the outside? Or maybe ditch Maven altogether?

Answer 1

A contract test module usually has a very strong relationship to the module implementing the contract.

Thus, I recommend to evolve both modules alongside each other within a parent project.

Make foo and bar modules of a multi-module maven project. Then make bar depend on foo like you suggested yourself. Assign both the same version ${parent.version}. This implies you use ${parent.version}-SNAPSHOT in between releases.

Keep evolving and releasing your project like you would with a single module, preferably by using the maven-release-plugin on release. It will raise the versions of all modules concurrently as part of the release:prepare goal.