name: generate-test-plan description: Create comprehensive unit test plans for Swift code with TDD methodology. Use this when planning tests for new features, ensuring test coverage, creating test checklists, or implementing Test-Driven Development practices.

Unit Test Plan Generator

Analyze Swift source files and generate comprehensive unit test plans with TDD focus and high coverage.

Instructions

When asked to create a test plan for a Swift component:

1. Analyze the Input: Identify the main class/struct, its public API (methods and properties), initializers, and dependencies.

2. Consider Test Categories:

   • Happy Path: Normal, expected inputs and outcomes
   • Edge Cases: nil, empty strings/collections, zero, negative values, extreme values
   • State Changes: Verify internal state is correctly modified
   • Invalid Inputs: Graceful behavior with unexpected/invalid data
   • Initializer Tests: Object's initial state with different parameters

3. Format as Markdown:

   • Title: # Test Plan for [ClassName]
   • Use checkboxes: - [ ] for each test case
   • Group under clear headings: ## Initializer, ## Method: myFunction()
   • Use descriptive names: test_when_given_this_should_do_that

Example

Input:

class TemperatureConverter {
    private(set) var celsius: Double

    init(celsius: Double) {
        self.celsius = celsius
    }

    func set(kelvin: Double) {
        guard kelvin >= 0 else { return }
        self.celsius = kelvin - 273.15
    }
}

Output:

# Test Plan for TemperatureConverter

## Initializer
- [ ] `test_init_withPositiveCelsius_shouldSetPropertyCorrectly`
- [ ] `test_init_withZeroCelsius_shouldSetPropertyCorrectly`
- [ ] `test_init_withNegativeCelsius_shouldSetPropertyCorrectly`

## Method: set(kelvin:)
- [ ] `test_setKelvin_withPositiveValue_shouldUpdateCelsiusCorrectly`
- [ ] `test_setKelvin_withZeroValue_shouldUpdateCelsiusCorrectly`
- [ ] `test_setKelvin_withNegativeValue_shouldNotUpdateCelsius`

Test Coverage Guidelines

• Test each public method with happy path, edge cases, and invalid inputs
• Verify state changes after method calls
• Test all initializer parameter combinations
• Ensure graceful error handling
• Test boundary conditions