[deploy] Checking Maven Central rules fails for submodules not producing jar archives

[mikemybytes]

The current implementation of the AbstractMavenDeployer#checkMavenCentralRules seems not to be prepared for a multi-module Maven project containing modules that don't produce jar archives. For example, verification fails on a submodule with <packaging>pom</packaging> with a following message:

[nexus2] submodule-with-pom-packaging-0.0.1-sources.jar is missing
(...)
[ERROR] Failed to execute goal org.jreleaser:jreleaser-maven-plugin:1.3.1:full-release (default-cli) on project multi-module-project: Execution default-cli of goal org.jreleaser:jreleaser-maven-plugin:1.3.1:full-release failed: Rules for publishing to Maven Central were not met
(...)
Caused by: org.jreleaser.model.JReleaserException: Rules for publishing to Maven Central were not met
    at org.jreleaser.sdk.commons.AbstractMavenDeployer.collectDeployables (AbstractMavenDeployer.java:116)
    at org.jreleaser.sdk.nexus2.Nexus2MavenDeployer.deploy (Nexus2MavenDeployer.java:54)
    at org.jreleaser.engine.deploy.maven.ProjectMavenDeployer.deploy (ProjectMavenDeployer.java:55)
    at org.jreleaser.engine.deploy.maven.MavenDeployers.deploy (MavenDeployers.java:124)
    at org.jreleaser.engine.deploy.maven.MavenDeployers.deploy (MavenDeployers.java:111)

An example project structure causing such issues could be observed here.

Probably, the Deployable class could be extended with a packaging type info, that could be then used to decide whether or not to expect sources and Javadoc jar archives.

[aalmiray]

Oof, absolutely. Staged artifacts with <packaging>pom</packaging> (such as BOMs and parent poms) will cause rules to fail.

[aalmiray]

Deployable could add a packaging property containing the value of <packaging>. This means parsing XML will be a must. Recall that <packaging> may not be present, in which case its default value is jar.

Simple XML parsing should be performed otherwise we'd have to resolve parent poms that may also be staged and that would complicate matters a lot.

[mikemybytes]

What about a good-old javax.xml? A simple XPath query like this should do the trick:

// warning: just a POC
try {
    Document document = DocumentBuilderFactory.newInstance()
                       .newDocumentBuilder()
                       .parse(new File(path));
    String query = "/project/packaging";
    String packaging = (String) XPathFactory.newInstance()
                   .newXPath()
                   .compile(query)
                   .evaluate(document, XPathConstants.STRING);
     // value or an empty string (default packaging)
} catch (ParserConfigurationException | IOException | SAXException | XPathExpressionException e) {
    throw new RuntimeException(e); // TODO: do something meaningful instead
}

I'll be happy to pick this up unless you're very into XML parsing 😉

[aalmiray]

Thank you @mikemybytes, we welcome contributions! 😄

[aalmiray]

Released in v1.4.0 -> https://github.com/jreleaser/jreleaser/releases/tag/v1.4.0