[GROOVY-7297] StackOverflowError Related To Trait Generics

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.4.1
• Assignee: Jochen Theodorou
• Reporter: Jeff Brown
• Created: 09/Feb/15 11:46
• Updated: 23/Feb/15 01:12
• Resolved: 10/Feb/15 10:07

Description

With the latest Groovy 2.4.1-SNAPSHOT the following code (attached as traitgenerics.zip) is problematic:

src/main/groovy/demo/SomeTrait.groovy

package demo

trait SomeTrait {
    String title
    
    public <T> List<T> someMethod(T data) {}
}

This test will fail:

src/test/groovy/demo/SomeTraitSpec.groovy

package demo

class SomeTraitSpec extends spock.lang.Specification {

    void 'test something'() {
        when:
        def sc = new Foo(title: 'some title')

        then:
        'some title' == sc.title
    }
}

class Foo implements SomeTrait {}

The test fails because the call to the Foo constructor results in a StackOverflowError.

java.lang.StackOverflowError
    at com.sun.beans.TypeResolver.erase(TypeResolver.java:242)
    at com.sun.beans.TypeResolver.erase(TypeResolver.java:243)
    at com.sun.beans.TypeResolver.erase(TypeResolver.java:243)
    at com.sun.beans.TypeResolver.erase(TypeResolver.java:243)

    ...

    at com.sun.beans.TypeResolver.erase(TypeResolver.java:243)
    at com.sun.beans.TypeResolver.erase(TypeResolver.java:243)
    at com.sun.beans.TypeResolver.erase(TypeResolver.java:274)
    at java.beans.FeatureDescriptor.getParameterTypes(FeatureDescriptor.java:387)
    at java.beans.MethodDescriptor.setMethod(MethodDescriptor.java:114)
    at java.beans.MethodDescriptor.<init>(MethodDescriptor.java:72)
    at java.beans.MethodDescriptor.<init>(MethodDescriptor.java:56)
    at java.beans.Introspector.getTargetMethodInfo(Introspector.java:1149)
    at java.beans.Introspector.getBeanInfo(Introspector.java:416)
    at java.beans.Introspector.getBeanInfo(Introspector.java:163)
    at demo.SomeTraitSpec.test something(SomeTraitSpec.groovy:7)

I noticed that if the class which implements the trait (Foo in the example above) is defined under src/main/groovy along with the trait, everything seems to work. The problem only occurs if Foo is defined elsewhere. In the example above is defined under src/test/groovy.