Filter .mvn/extensions.xml also for a project without a POM

[slawekjaranowski]

The problem

A project run by the plugin can be denoted either by a path to its pom.xml or merely by a path to its base directory - the latter for a project which has no POM at all (scanProjectsDirectory() / collectProjects() keep the bare directory in that case, and runBuild() then invokes Maven on the directory).

The filtering loop in cloneProjects() assumed the first form only:

File pomFile = new File(cloneProjectsTo, projectPath);
...
File baseDir = pomFile.getParentFile();
File mvnDir = new File(baseDir, ".mvn");

For a POM-less project projectPath is the project directory, so getParentFile() points at its parent - the clone root. The plugin then looks for <cloneProjectsTo>/.mvn/extensions.xml instead of <cloneProjectsTo>/<project>/.mvn/extensions.xml, and the project's own .mvn/extensions.xml is never interpolated: the @...@ tokens are passed to Maven verbatim. The failure is silent - no warning, no error.

The fix

Determine the base directory the same way runBuild() does - the project directory itself when the path denotes a directory, its parent otherwise. The now redundant mvnDir.isDirectory() check is dropped (extensionsFile.isFile() already implies it) and pomFile is renamed to projectFile, since that path is not always a POM - which is what caused the bug in the first place.

Tests

The existing filtering-extensions IT gains a second test project without a pom.xml (only .mvn/extensions.xml with @project.*@ tokens, plus invoker.properties with invoker.goals = --version so Maven can run POM-less). Verified that the IT fails without the production change and passes with it.

On the way the IT verify script has been converted from BeanShell to Groovy - Groovy assertions report what failed on their own, so the explicit System.out reporting and the try/catch/return true scaffolding are gone (75 lines -> 35).