Migrating to Spock 2.0 M1 with JUnit 5 – Gradle & Maven Setup Guide

Spock 2.0 M1 Overview

Spock 2.0 M1 is a major upgrade built on JUnit 5 and Groovy 3 (which requires JDK 9+). It is a pre‑release version intended to gather feedback on the migration to the JUnit Platform; it is not recommended for production projects.

JUnit Platform Support

The core change is the migration to JUnit 5 via JUnit Platform 1.5. Tests written with Spock are automatically discovered and executed by any tool that supports the JUnit Platform (IDE, build tools, CI, etc.). Platform features also apply to Spock tests.

Adding Spock 2 to a Gradle Project

Update the Spock dependency:

testImplementation('org.spockframework:spock-core:2.0-M1-groovy-2.5')

Activate the JUnit Platform in the test task:

test {
    useJUnitPlatform()
}

Adding Spock 2 to a Maven Project

<dependency>
  <groupId>org.spockframework</groupId>
  <artifactId>spock-core</artifactId>
  <version>2.0-M1-groovy-2.5</version>
  <scope>test</scope>
</dependency>

If the junit-platform-engine transitive dependency is present, the Surefire plugin (version 3.0.0+) will run the tests on the JUnit Platform by default.

Other Changes

Because of the JUnit Platform migration, the number of additional changes in Spock 2.0 M1 is limited, making regression hunting easier. The required Java version is now 8. All parameterized tests run automatically, but the old spock-global-unroll feature is not yet supported.

Some extensions such as SpockReportingExtension are temporarily disabled.

JUnit 4 Rule Issues

Tests that use JUnit 4 @Rule or @ClassRule may fail with NullPointerException or IllegalStateException because the JUnit Platform no longer supports the Rules API. To ease migration, Spock provides the spock-junit4 extension, which wraps JUnit 4 rules as Spock extensions.

Add the dependency:

testImplementation 'org.spockframework:spock-junit4:2.0-M1-groovy-2.5'

Or in Maven:

<dependency>
    <groupId>org.spockframework</groupId>
    <artifactId>spock-junit4</artifactId>
    <version>2.0-M1-groovy-2.5</version>
    <scope>test</scope>
</dependency>

Other Known Issues

Spock 2.0 M1 compiles and runs only with Groovy 2.5.8. Attempts to use Groovy 3.0 result in a hidden error such as:

Could not instantiate global transform class org.spockframework.compiler.SpockTransform ... because of exception java.lang.reflect.InvocationTargetException

This limitation reduces the ability to run Spock tests that depend on Groovy 3, especially in edge cases. Future releases may add compatibility or remove the restriction.