Refactor project for modern Gradle

[rubengees]

This is a major refactor of the plugin to support modern Gradle versions.

The goals are:

• Latest Gradle version support (without warnings).
• Build cache support.
• Configuration avoidance.
• Explicit Kotlin support.
• Unified configuration closure (everything in wsdl2java).
• Near to no configuration for the user.
  • Automatic configuration of sourceSets.
  • Automatic adding of dependencies (cxf and needed ones for Java 9+ support).
• More?

Code Changes

Wsdl2JavaPlugin

• Use configuration avoidance APIs wherever possible.
• Check for Kotlin plugin(s) and make tasks depend on ours if present.
• Check for java 9+ and add necessary dependency to our wsdl2java configuration and the compile configuration.
• Hardcode the directory for the generated sources. I have not found a way to make this configurable and also give it to Kotlin plugin. This is a Gradle lifecycle problem, because the Kotlin plugin reads from the sourceSets before we get the setting from the user.

Wsdl2JavaTask

• Use the unified extension instead of individual properties.
• Make it a @CacheableTask (which allows Gradle's build cache to work).

Clean task

• Removed. Gradles default clean task takes care of it.

Structure

• Moved the consumer project into a test project under src/test/resources/test-project and added Gradle TestKit tests for it.
• The plugin is now a first-level project.
• Added a Kotlin test project.

This contains at least the following breaking changes:

• Older Gradle versions are not supported anymore. If needed, I can try to improve backwards compatibility.
• Clean task removed.
• generatedWsdlDir property removed and default changed.
• wsdlDir default changed.

[nilsmagnus]

Awesome! I will have a look at it later today, but this looks really good :+1:

[rubengees]

Cool, thanks!

What would be the minimum Gradle version this plugin should support? I have checked (and added tests) that we support Gradle 4.10+ with this PR. Do we need to go lower? If we do, I'd add some compat methods that check for the Gradle version and call older APIs.

[rubengees]

@nilsmagnus Friendly ping :) Did you find any time to check this?

[nilsmagnus]

Sorry for the delay :)

LGTM, thanks for the contribution. I added you to the collaborators so you can fix minor things without my approval :)

[KrauseStefan]

This is great work!

Will await the next published release :)

[ben-manes]

This has a lot of breaking changes, no migration steps, and no changelog. Please be kinder to your users as a lot of behavior no longer works correctly in a Goovy build. I'm not exactly excited to reverse engineer your code to upgrade my usage.

[rubengees]

You are right, sorry for that.