[ErkoRisthein]

@EnableSnapshots can't start on Groovy 6, so every Spock spec that uses it fails at initialization:

org.spockframework.runtime.extension.ExtensionException: Failed to instantiate extension 'au.com.origin.snapshots.spock.SnapshotExtension'
Caused by: java.lang.NoClassDefFoundError: org/codehaus/groovy/runtime/callsite/CallSiteArray

The module is compiled with dynamic Groovy 2.5.8, so its classes carry call site caches built on CallSiteArray, and Groovy 6 no longer has that class.

Change

• @CompileStatic on SnapshotExtension and SnapshotMethodInterceptor, so the compiled classes no longer reference CallSiteArray. The module still compiles against Groovy 2.5.8 and Spock 1.3.
• Plain for loops replace eachWithIndex and the spread operator, so the static code doesn't bind to DefaultGroovyMethods signatures at compile time.
• log is typed as Logger, which static compilation needs.
• New GroovyRuntimeCompatibilitySpec fails if an extension class references CallSiteArray. The module's tests run on Groovy 2.5, so this checks the bytecode rather than running on Groovy 6.

Verification

./gradlew :java-snapshot-testing-spock:build passes.

I also published the branch with publishToMavenLocal and ran a downstream project's snapshot tests against it: 7 test classes (Spock and JUnit 5), 34 tests, compiled with the Groovy version in the table.

Library	Groovy	Spock	Result
4.2.1	6.0.0	2.5-groovy-6.0	The 2 Spock classes fail to initialize with the error above
this branch	6.0.0	2.5-groovy-6.0	34 pass
this branch	5.1.3	2.5-groovy-5.0	34 pass

Static compilation binds method calls at compile time, so the risk to check is a Spock API that differs between 1.3 and later versions. Spock 1.3 is covered by the module's tests and 2.5 by the runs above. I did not run other Spock 2.x versions.

[Copilot]

🟢 Approval recommended

No active review issues remain for the Spock extension’s Groovy 6 compatibility changes.

No open issues 🎉

What changed in this PR

Updates the Spock snapshot extension to load on Groovy 6 by removing dynamically compiled references to the deleted CallSiteArray class, while retaining the existing Groovy 2.5.8 and Spock 1.3 compilation baseline.

Changes:

• Statically compiles both extension classes and adds explicit types where needed.
• Replaces dynamic iteration and spread operations with plain loops.
• Adds a bytecode regression test that checks for CallSiteArray references.

File	Description
java-snapshot-testing-spock/​src/​test/​groovy/​au/​com/​origin/​snapshots/​spock/​GroovyRuntimeCompatibilitySpec.groovy	Checks compiled extension classes for references to the removed call-site cache.
java-snapshot-testing-spock/​src/​main/​groovy/​au/​com/​origin/​snapshots/​spock/​SnapshotMethodInterceptor.groovy	Adds static compilation, explicit types, and indexed parameter iteration.
java-snapshot-testing-spock/​src/​main/​groovy/​au/​com/​origin/​snapshots/​spock/​SnapshotExtension.groovy	Adds static compilation and registers feature interceptors through a plain loop.

_{Review effort: Balanced}