Support settings.xml in rewriteRun

[jevanlingen]

What's changed?

The rewriteRun test runner now respects the local settings.xml file from the Maven configuration directory (~/.m2/settings.xml by default).

What's your motivation?

The settings.xml file is often used to define mirrors, which can redirect all artifact requests to an internal repository manager such as Artifactory. For example:

<mirrors>
  <mirror>
    <id>artifactory</id>
    <mirrorOf>*</mirrorOf>
    <url>https://my.own.artifactory.com</url>
  </mirror>
</mirrors>

For some company environments, direct access to external repositories such as https://repo.maven.apache.org/maven2 is blocked (often returning a 403). Without support for settings.xml, rewriteRun tests would fail in such environments because dependencies could not be resolved.

Additionally, this change supports scenarios where mirrors are used to discard certain repositories, for example:

<mirror>
  <id>skip-sonatype-nexus-snapshots</id>
  <mirrorOf>sonatype-nexus-snapshots</mirrorOf>
  <url>http://nonexistent.invalid</url>
</mirror>

Checklist

• I've added unit tests to cover both positive and negative cases
• I've read and applied the recipe conventions and best practices
• I've used the IntelliJ IDEA auto-formatter on affected files

[jevanlingen]

I now made it work with this flag. You could argue though, if there is no maven-settings available in the context, you always want to read the maven settings from local. What do you guys think?

[Jenson3210]

Do we also have to set this in the gradle/maven plugins or do they already do MavenSettings.readMavenSettingsFromDisk(ctx)?

[jevanlingen]

I guess they don't have to, because these plugins will just start running the tests. The tests themselves call the rewriteRun functions, which in turn will just set the MAVEN_SETTINGS_LOAD_FROM_DISK property. With other words, it does not really matter how/which build tool starts the tests, as you don't need any configuration from outside the scope of the tests.