Boxed Boolean getter methods prefixed by `is` are not properly mocked in Groovy <=3

[piotrminkina]

Describe the bug

In Groovy, it is possible to declare a getter method for a returned Boolean value, where the prefix get can be replaced by is. A subsequent reference to such a method in shorthand notation works correctly in both cases, but Spock cannot correctly mock such a method when the shorthand notation is used.

To Reproduce

Consider the following example specification:

class SimpleSpecification extends Specification {
    def 'test stub assertions'(VcsDetails vcsDetails) {
        expect:
        verifyAll(vcsDetails) {
            lastTag == 'current-tag'
            cleanTag == true
            isCleanTag == true
        }

        where:
        vcsDetails << [
            Stub(VcsDetails) {
                lastTag >> 'current-tag'
                cleanTag >> true // condition will be NOT satisfied
                isCleanTag >> true
            },
            Stub(VcsDetails) {
                lastTag >> 'current-tag'
                isCleanTag() >> true // condition will be satisfied
                isCleanTag >> true
            },
        ]
    }

    static interface VcsDetails {
        String getLastTag()
        Boolean isCleanTag()
        Boolean getIsCleanTag()
    }
}

Expected behavior

Spock will correctly mock the isCleanTag() method using shorthand.

Actual behavior

Spock does not mock the isCleanTag() method using a shorthand. The example specification posted ends with an error only for the first test case, where shorthand is used.

test stub assertions [vcsDetails: Mock for type 'VcsDetails', #0]
Condition not satisfied:

cleanTag == true
|        |
false    false

	at com.example.SimpleSpecification.test stub assertions_closure1(SimpleSpecification.groovy:10)
	at app//groovy.lang.Closure.call(Closure.java:412)
	at app//spock.lang.Specification.verifyAll(Specification.java:276)
	at com.example.SimpleSpecification.test stub assertions(SimpleSpecification.groovy:8)

Java version

openjdk 11.0.26 2025-01-21
OpenJDK Runtime Environment Temurin-11.0.26+4 (build 11.0.26+4)
OpenJDK 64-Bit Server VM Temurin-11.0.26+4 (build 11.0.26+4, mixed mode)

Buildtool version

---

Gradle 8.2.1

Build time: 2023-07-10 12:12:35 UTC
Revision: a38ec64d3c4612da9083cc506a1ccb212afeecaa

Kotlin: 1.8.20
Groovy: 3.0.17
Ant: Apache Ant(TM) version 1.10.13 compiled on January 4 2023
JVM: 11.0.26 (Eclipse Adoptium 11.0.26+4)
OS: Linux 6.13.6-200.fc41.x86_64 amd64

What operating system are you using

Linux

Dependencies

+--- org.spockframework:spock-core:2.3-groovy-3.0
| +--- org.junit:junit-bom:5.9.0
| | +--- org.junit.platform:junit-platform-engine:1.9.0 (c)
| | +--- org.junit.platform:junit-platform-launcher:1.9.0 (c)
| | --- org.junit.platform:junit-platform-commons:1.9.0 (c)
| +--- org.junit.platform:junit-platform-engine -> 1.9.0
| | +--- org.junit:junit-bom:5.9.0 ()
| | +--- org.opentest4j:opentest4j:1.2.0
| | --- org.junit.platform:junit-platform-commons:1.9.0
| | --- org.junit:junit-bom:5.9.0 ()
| --- org.hamcrest:hamcrest:2.2
+--- net.bytebuddy:byte-buddy:[1.14.0,1.15.0) -> 1.14.19
--- org.objenesis:objenesis:[3.4,3.5) -> 3.4

Additional context

No response

[AndreasTu]

@piotrminkina I wrote some tests your issue in #2244.
But this only is an issue in Groovy <= 3, because in Groovy >=4, your code is not vaild, see below.

I can't reproduce your finding with the version 2.4-master on Groovy 4, but I can with Groovy 3.
It is also not reproducible with Spock 2.3 and Groovy 4, see.
But with Spock 2.3 and Groovy 3 (as you said), see.

Although worth noting, that you are using boxed Boolean is getters in your sample.
And it only fails when using boxed Booleans.

Where according to Groovy >=4 in the tests in #2244:
An is getter for a boxed Boolean does not exist, and therefore throws an MissingPropertyException
on mocking and access.
Although according to Groovy <=3 it is a vaild getter.

I have not yet a fix for the Groovy <=3 issue.

[Vampire]

Hm, we probably need different matching logic for <=3 and >=4.

In apache/groovy#1599 for Groovy 4 there were some intentional changes around this to align Groovy behavior to JavaBeans spec.

Maybe we should add to the big pretty access consistency test we just added also some boolean and Boolean properties and verify whether get and is getters are treated the same with and without mock object and also their preference which changed also in Groovy 4.

See also https://issues.apache.org/jira/browse/GROOVY-10133.

And https://issues.apache.org/jira/browse/GROOVY-9618 (not about boolean, but one character uppercase property and getter for it.

[AndreasTu]

The PR #2244 fixes the issue for Groovy <=3.