tdd-practices_skill

Overview

This skill guides test-driven development workflows, designs practical test cases, and recommends mocking strategies for clean, maintainable tests. It focuses on Red-Green-Refactor cycles and produces concrete test templates and step-by-step TDD guidance for multiple languages and frameworks. The output is actionable: test cases, TDD steps, mock patterns, and basic coverage analysis suggestions.

How this skill works

Provide an action (design_tests, tdd_guide, mock_strategy, coverage_analysis) and a target language; optionally include code, feature description, or dependency list. The skill analyzes public behavior, identifies edge cases and priorities, and returns test case templates, TDD steps, recommended mock types, or a brief coverage checklist. Defaults map languages to common frameworks (e.g., pytest for Python) and validation enforces supported languages and actions.

When to use it

• When you need concrete unit or integration test templates for existing code.
• When adopting or coaching a Red-Green-Refactor TDD workflow for a feature.
• When deciding between stubs, mocks, spies, or fakes for external dependencies.
• When preparing a focused test plan to increase baseline coverage quickly.
• When you want minimal code examples to start tests in a specific test framework.

Best practices

• Start small: write a single failing test that asserts one behavior before implementing code.
• Prefer minimal implementation in green phase; avoid premature optimization.
• Keep tests deterministic: isolate external systems with appropriate mocks, stubs, or fakes.
• Verify interactions only when behavior depends on them; use spies or mocks sparingly.
• Refactor tests and production code together to keep tests expressive and maintainable.

Example use cases

• Design unit tests for a service method that calls payment and repository layers.
• Generate a Red-Green-Refactor plan for adding a discount-code feature to checkout.
• Recommend a mocking strategy for third-party HTTP clients and database access.
• Produce pytest templates for Python functions and suggest priority and edge cases.
• Provide a quick coverage checklist for critical flows before a release.