Guides the Test-Driven Development methodology: the Red-Green-Refactor cycle of writing failing tests before implementation code, then making them pass with minimal code, then refactoring. Use when the user asks to do TDD, practice test-driven development, follow red-green-refactor, write tests first, apply test-first methodology, or implement a feature using TDD workflow with pytest, Vitest, ERT, or Zod. NOT for choosing or setting up test frameworks (use testing-framework), NOT for finding and fixing bugs or analyzing stack traces (use debugging), NOT for reviewing existing code or PRs (use code-review).
npx claudepluginhub viktorbezdek/skillstack --plugin test-driven-developmentThis skill uses the workspace's default tool permissions.
A unified, comprehensive skill for implementing Test-Driven Development across multiple languages, frameworks, and testing levels.
references/coverage-validation.mdreferences/elisp-tdd.mdreferences/extended-patterns.mdreferences/general-tdd.mdreferences/playwright-best-practices.mdreferences/playwright-e2e-patterns.mdreferences/python-tdd.mdreferences/refactoring-with-tests.mdreferences/test-design-patterns.mdreferences/test-structure-guide.mdreferences/vitest-patterns.mdreferences/zod-testing-patterns.mdscripts/coverage_analyzer.pyscripts/coverage_check.pyscripts/run_tests.pyscripts/skill_validator.pyscripts/test_template_generator.pyscripts/with_server.pytemplates/elisp_test_template.eltemplates/python_test_template.py.templateCompares coding agents like Claude Code and Aider on custom YAML-defined codebase tasks using git worktrees, measuring pass rate, cost, time, and consistency.
Designs and optimizes AI agent action spaces, tool definitions, observation formats, error recovery, and context for higher task completion rates.
Designs, implements, and audits WCAG 2.2 AA accessible UIs for Web (ARIA/HTML5), iOS (SwiftUI traits), and Android (Compose semantics). Audits code for compliance gaps.
A unified, comprehensive skill for implementing Test-Driven Development across multiple languages, frameworks, and testing levels.
RED -> Write a failing test first (define expected behavior)
GREEN -> Write minimal code to pass (just enough, don't over-engineer)
REFACTOR -> Improve code quality (clean up while tests pass)
REPEAT
def test_descriptive_name():
"""Clear description of what is being tested."""
# Arrange - Set up test data and conditions
input_data = prepare_test_data()
expected_result = "expected_value"
# Act - Execute the code under test
actual_result = function_under_test(input_data)
# Assert - Verify the results
assert actual_result == expected_result
Fast, isolated tests for individual functions/methods.
Tests for component interactions and external services.
Full system tests through the user interface.
# Good
def test_calculate_discount_returns_zero_for_empty_cart():
...
# Bad
def test_discount():
...
# Good - specific assertion with message
assert result.status == "success", f"Expected success but got {result.status}"
# Bad - generic assertion
assert result
See Extended Patterns for detailed language-specific guidance (Python/pytest, TypeScript/Vitest, Playwright E2E, Emacs Lisp/ERT), the 6-phase TDD workflow, quick reference commands, and troubleshooting.
references/extended-patterns.md - Detailed code examples and language guidancereferences/general-tdd.md - TDD principles and methodologyreferences/python-tdd.md - Python-specific TDD practicesreferences/elisp-tdd.md - Emacs Lisp TDD with ERTreferences/vitest-patterns.md - Vitest testing patternsreferences/playwright-e2e-patterns.md - Playwright best practicesreferences/playwright-best-practices.md - E2E testing guidelinesreferences/zod-testing-patterns.md - Schema validation testingreferences/test-design-patterns.md - Common test patternsreferences/test-structure-guide.md - Test organizationreferences/refactoring-with-tests.md - Safe refactoring practicesreferences/coverage-validation.md - Coverage analysis guidescripts/run_tests.py - Test runner utilityscripts/coverage_analyzer.py - Coverage analysis toolscripts/coverage_check.py - Coverage threshold checkerscripts/test_template_generator.py - Generate test boilerplatescripts/skill_validator.py - Validate test implementationstemplates/python_test_template.py.template - pytest test templatetemplates/elisp_test_template.el - ERT test templatetemplates/test_checklist.md - Coverage checklist templatetemplates/tdd_session_log.md - TDD session logging templateThis skill consolidates best practices from test-driven-development-tdd-skill, testing-guide-skill, test-agent-technical-skill, and development-workflow-specialist.