Testing & TDD Skills

Test-driven development workflows and testing infrastructure for Apple platform apps. Works with both new and existing codebases.

When This Skill Activates

Use this skill when the user:

Wants to do TDD (test-driven development) with AI-generated code
Needs to add tests before refactoring existing code
Wants to fix a bug using the red-green-refactor cycle
Needs test infrastructure (factories, mocks, contracts)
Asks about snapshot/visual regression testing
Wants to ensure AI-generated code is correct via tests

Available Skills

For Existing Codebases

characterization-test-generator/ Capture current behavior of existing code before refactoring. Generates tests that document what code actually does (not what it should do), giving you a safety net for AI-assisted refactoring.

tdd-bug-fix/ Reproduce-first bug fix workflow. Write a failing test that demonstrates the bug, then fix it. Ensures the bug never regresses — critical when AI generates fixes.

tdd-refactor-guard/ Pre-refactor safety checklist. Verifies test coverage exists before allowing AI to touch existing code. Prevents the "refactor without a safety net" problem.

For New Code

tdd-feature/ Red-green-refactor scaffold for new features. Generates the failing test first, then guides implementation to make it pass, then refactors. The core TDD workflow.

test-contract/ Protocol/interface test suites. Define the contract (e.g., "any DataStore must handle empty state, single item, 100 items, and errors"), and it generates a test suite any implementation must pass.

Infrastructure

snapshot-test-setup/ SwiftUI visual regression testing using swift-snapshot-testing. Generates snapshot test boilerplate, configuration, and CI integration.

test-data-factory/ Test fixture factories for your models. Makes writing tests faster by eliminating boilerplate data setup. Supports Builder pattern and static factory methods.

integration-test-scaffold/ Cross-module test harness with mock servers, in-memory stores, and test configuration. For testing networking + persistence + business logic together.

How to Use

Identify whether user is working on new code or existing code
Read the relevant skill's SKILL.md for detailed workflow
Detect project context (testing framework, architecture, existing tests)
Generate tests following the skill's workflow
Verify tests compile and run

Relationship to test-generator

The generators/test-generator/ skill generates test boilerplate (unit, integration, UI tests). These testing skills are complementary — they focus on workflows and methodology (TDD cycle, characterization testing, contracts) rather than just test file generation.

Cross-reference:

Use test-generator for "add tests to this class"
Use testing/tdd-feature for "I want to TDD this new feature"
Use testing/characterization-test-generator for "I need to safely refactor this"
Use testing/tdd-bug-fix for "fix this bug and make sure it never comes back"