What is the 'Iron Rule' for Spock testing?

The Iron Rule mandates that writing three or more similar test methods requires you to use a 'where:' block to consolidate them into a single data-driven test.

Why is data-driven testing emphasized?

Data-driven testing in Spock reduces maintenance time, makes patterns obvious, and allows developers to add new test cases by simply adding a row to a table rather than writing a new method.

Does this skill help with test readability?

Yes, it enforces descriptive, sentence-like test names and the use of the #variable syntax in method names to clearly identify which data scenario is being tested.

Can I use this for existing Java projects?

Absolutely. It is specifically designed to assist in refactoring existing verbose test suites into more maintainable Spock specifications.

How does this skill handle mocks and stubs?

It ensures stubs (returning fake data) are placed in the 'given:' block using the '>>' operator, while mocks (verifying interactions) are placed in the 'then:' block using the '*' operator.

Spock Testing Best Practices

Name: Spock Testing Best Practices
Author: mbarbieri

bymbarbieri

•

Security & Testing

Enforces data-driven testing and optimal Spock block structure for clean, maintainable Java and Groovy test suites.

This skill optimizes how Claude writes and refactors Java tests by strictly enforcing the Spock Framework's best practices, with a primary focus on data-driven testing. It mandates the use of 'where:' blocks for repetitive test logic, ensures correct separation between stubs in 'given:' blocks and mocks in 'then:' blocks, and promotes human-readable, parameter-aware test naming. By applying the 'Iron Rule'—which requires consolidation whenever three or more similar tests appear—this skill helps developers significantly reduce test boilerplate while improving coverage and long-term maintainability.

Key Features

01Enforces 'where:' blocks for all parameterized and data-driven scenarios

02Ensures proper Mock vs. Stub placement and syntax usage

03Promotes descriptive, sentence-based test names with variable interpolation

042 GitHub stars

05Validates correct Spock block sequence (given, when, then, expect, where)

06Provides a checklist for identifying and refactoring redundant test structures

Use Cases

01Consolidating multiple repetitive test methods into a single, clean data-driven specification

02Ensuring architectural consistency and best practices during Java unit test reviews

03Scaffolding new integration tests with complex input-output validation matrices

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add mbarbieri/my-claude spock

For use in Claude.ai and ChatGPT