GsonUnitTestMixin should be considered only for tests

[jljouannic]

Because this plugin embeds a GsonUnitTestMixin class which inherits from GsonUnitTestMixin, makes it dependant to grails-test, grails-plugin-testing and spring-test artifacts. This is particularly a problem if someone (me) wants to use this plugin in a mavenized grails project.

If I simply add a dependency to this plugin in the pom.xml file, executing a mvn test leads to a compilation error on GsonUnitTestMixin.groovy because GsonUnitTestMixin class cannot be resolved.

I tried to change the scope of both grails-plugin-testing and grails-test library from test to provided. This helped to build the project, but it brought unwanted (but quite expected) side effects at runtime. After a request to the application, the code which serialize an object to JSON using GSON throws the following:

java.lang.ClassNotFoundException: org.springframework.mock.web.MockHttpServletRequest
    at java.lang.Class.privateGetDeclaredMethods(Class.java:2436)
    at java.lang.Class.getDeclaredMethods(Class.java:1793)
    at org.codehaus.groovy.util.LazyReference.getLocked(LazyReference.java:46)
    at org.codehaus.groovy.util.LazyReference.get(LazyReference.java:33)
    at grails.plugin.gson.converters.GSON.render(GSON.groovy:57)
    at grails.plugin.gson.api.ArtefactEnhancer$_enhanceControllers_closure1.doCall(ArtefactEnhancer.groovy:29)
    ...

I wonder if their is a way to only consider the GsonUnitTestMixin class just for tests.

[robfletcher]

That's interesting. I've never used Grails with maven so I wasn't aware of the implications of including test artifacts in the plugin. If the plugin depended on a binary jar file that contained the test support classes would you be able to exclude it from your maven build?

[jljouannic]

If the plugin depended on a binary jar file that contained the test support classes would you be able to exclude it from your maven build?

Don't you mean the opposite? The test support class depends on the others, not the contrary. But yes, I think that would work. With this solution I would be able to simply add a compile dependency to the gson plugin to make everything work. And if I wanted to write some tests about serialization, I could then add a test dependency to the binary jar you mention.

I bet you are not the only one to propose a test support class for a grails plugin. I wonder how it is done in those?