[GROOVY-7876] ClassCastException when calling DefaultTypeTransformation#compareEqual

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.4.6
• Fix Version/s: 2.4.8
• Assignee: Paul King
• Reporter: Andrew White
• Created: 27/Jun/16 22:33
• Updated: 01/Feb/17 23:18
• Resolved: 21/Jul/16 23:33

Description

It appears that comparing two objects that both implement comparable with DefaultTypeTransformation#compareEqual is not safe in all cases. Consider enums for example, which throw exceptions when compared to differing classes.

This is using Eclipse Collections for pairs but the idea is the same in general.

    enum E1 {A, B, C}
    enum E2 {D, E, F}

    def "test groovy oddness"() {
        when:
        def test = DefaultTypeTransformation.compareEqual(
            Tuples.pair(E1.A, 1), 
            Tuples.pair(E2.D, 1))

        then:
        assert test == false
    }

Stacktrace

java.lang.ClassCastException
	at java.lang.Enum.compareTo(Enum.java:180)
	at java.lang.Enum.compareTo(Enum.java:55)
	at org.eclipse.collections.impl.tuple.PairImpl.compareTo(PairImpl.java:95)
	at org.eclipse.collections.impl.tuple.PairImpl.compareTo(PairImpl.java:22)
	at com.GroovyTests.test groovy oddness(GroovyTests.groovy:36)

Issue Links

• is cloned by: GROOVY-7892 CLONE - ClassCastException when calling DefaultTypeTransformation#compareEqual
• is related to: GROOVY-4046 1 == new Object() throws ClassCastException
• links to: GitHub Pull Request #368
• links to: GitHub Pull Request #372