Filter classpath scanning for FrontendDependencies

[oliveryasuna]

Describe your motivation

Large projects may have 100s of dependencies. It may not be necessary to scan all of these to find frontend configurations and dependencies. In particular, it takes the Vaadin Gradle plugin's vaadinBuildFrontend task 30+ seconds to scan our project. I assume it would be the same/similar with the Maven plugin, as they share code.

Describe the solution you'd like

Add a configuration property to whitelist dependency JARs and packages. Packages too because some packages in main may contain business-only code and have nothing to do with Vaadin.

This could be a huge win for enterprise applications.

Context

In lieu of Vaadin's proper Gradle caching support, we are attempting to speed up builds. #17941

[oliveryasuna]

Does this actually already exist but is undocumented? VaadinFlowPluginExtension#classpathFilter?

[oliveryasuna]

I was able to use this undocumented feature and opened some relevant issues:

• Document the Gradle plugin's filterClasspath property/closure docs#3477
• Support filterClasspath in Maven plugin, similar to Gradle plugin #19542

Closing this issue.