Problem With Autogenerated grails.factories

[jeffscottbrown]

The following is happening with Grails 3.1.12.

See project at https://github.com/jeffbrown/factories-problem.

src/main/resources/META-INF/services/grails.factories:

org.grails.taglib.encoder.OutputContextLookup=problem.FooOutputContextLookup

src/main/groovy/problem/SpecialService.groovy

package problem

import grails.artefact.Enhances

@Enhances('Service')
trait SpecialService {
}

If grails.factories doesn't exist, GlobalGrailsClassInjectorTransformation is supposed to generate a new one that looks like this:

grails.compiler.traits.TraitInjector=problem.SpecialServiceTraitInjector

If one does exist, instead of creating a new one, the existing one is supposed to be updated with the reference to problem.SpecialServiceTraitInjector.

A problem exists right now in that the compiler is looking to see if a new one exists at build/classes/main/META-INF/grails.factories but it actually exists at build/resources/main/META-INF/services/grails.factories. This results in the system creating a new one instead of appending to the existing one.

In the project linked above run ./gradlew clean jar. That will result in the following:

factories-problem master $ cat build/classes/main/META-INF/grails.factories 
#Grails Factories File
#Tue Oct 18 19:21:39 CDT 2016
grails.compiler.traits.TraitInjector=problem.SpecialServiceTraitInjector
factories-problem master $ 
factories-problem master $ cat build/resources/main/META-INF/services/grails.factories 
org.grails.taglib.encoder.OutputContextLookup=problem.FooOutputContextLookup

The META-INF/services/grails.factories that is added to build/libs/factories-problem-0.1.jar looks like this:

org.grails.taglib.encoder.OutputContextLookup=problem.FooOutputContextLookup

I think the problem is at https://github.com/grails/grails-core/blob/991ef0074b2eecfabaf4c770084ebb9bb1bfcd64/grails-core/src/main/groovy/org/grails/compiler/injection/GlobalGrailsClassInjectorTransformation.groovy#L146. source.configuration.targetDirectory evaluates to build/classes/main.

The net effect is that if a plugin provides a trait marked with @Enhances and the plugin also happens to contain a grails.factories file, the @Enhances won't work because the grails.factories won't contain the necessary metadata. A workaround is to put the metadata in the existing grails.factories by hand.

[jeffscottbrown]

I will work up a fix tomorrow or Friday.