BDD Test File Generator Skill

BDD Test File Generator

Generate behavior-driven test files that focus on public API and observable behavior.

Quick Start Workflow

Read the source file to understand what needs to be tested
Identify the public API - all exported functions, constants, hooks, or component props
Check for existing test setup - look for setup.ts, vitest.config.ts, or existing test files
Generate the test file using patterns from references/patterns.md

Core Principle

Test public API and observable behavior only, never internal implementation:

Hooks/Components: Test user interactions, props, rendered output
Functions/Utilities: Test inputs → outputs, not internal algorithm steps
Constants: Test exported values are correct

Test Description Style

Use BDD-style descriptions with flexible GIVEN/WHEN/THEN/AND comments:

// Full form
// GIVEN an unauthenticated user
// WHEN the protected route is accessed
// THEN the user should be redirected

// With AND for multiple assertions
// GIVEN a user is authenticated
// WHEN the profile page loads
// THEN the username should be displayed
// AND the avatar should be visible

// Simple form (no WHEN needed)
// GIVEN an empty array
// THEN length should be zero

// Multiple conditions
// GIVEN a valid token
// AND the user has admin role
// WHEN accessing admin panel
// THEN access should be granted

Coverage Requirements

Primary success paths (happy path)
Edge cases (empty strings, null, boundaries)
Error states (graceful error handling)
All exported items

References

references/patterns.md - Detailed test patterns and mock handling
references/examples.md - Complete example test files

Agent Skills: BDD Test File Generator