gen-test

name	gen-test
description	Generate tests for a Kotlin class following NutriSport conventions. Use this skill whenever the user asks to write tests, add test coverage, create unit tests, or says "test this", "cover this", "write tests for X". Also use when user mentions a specific ViewModel, UseCase, Mapper, or Repository and wants it tested. Handles both pure use case tests and ViewModel tests with Turbine/Mokkery.
disable-model-invocation	true

Generate tests for: $ARGUMENTS

Context

This is a KMP project. Tests go in src/commonTest/kotlin/ mirroring source structure. The project uses kotlin.test, Turbine for Flows, Mokkery for mocking, assertk for assertions.

What to test by class type

Type	What to test	Mocking	Flow testing
UseCase (pure)	invoke() success/error paths	Fake repository	No (unless returns Flow)
UseCase (with repo)	invoke() delegates correctly, error propagation	Fake repository	Turbine if returns Flow
ViewModel	State transitions (Loading→Content), error handling, user actions	Fake repos via constructor	Turbine for StateFlow
Mapper	Field mapping, edge cases (null, empty), enum conversion	None (pure functions)	No
Repository	DTO→Domain mapping, error wrapping	Mock data source	Turbine for Flow returns

Process

1. Read the source file to understand what to test
2. Determine the class type (see table above) to pick the right testing approach
3. Check for existing tests, fake data factories, and Fake repositories in the module's commonTest
4. If ViewModel/UseCase test needs a Flow-based repository — create Fake{Entity}Repository with MutableSharedFlow (see examples/fake-repository.kt)
5. Reference examples/usecase-test.kt for pure UseCase tests
6. Reference examples/viewmodel-test.kt for ViewModel tests with Turbine
7. Reference examples/mapper-test.kt for pure mapper tests
8. For full recipes and pitfalls → see references/testing-patterns.md
9. Create fake data factories (fakeProduct(), fakeCustomer()) if not yet present
10. Write tests covering: happy path, error path, edge cases
11. Run: ./gradlew :{module}:allTests --tests "*{TestClass}"
12. Verify all pass

Conventions

• Naming: `should X when Y` backtick format
• AAA pattern: // Arrange → // Act → // Assert comments
• Flows: Always Turbine (test { awaitItem() }) — never .first() or .toList()
• Mocking: Mokkery — every { }, verify { }, mock<Interface>()
• Coroutines: runTest + StandardTestDispatcher() + Dispatchers.setMain()
• Assertions: assertk — assertThat(x).isEqualTo(y), isInstanceOf<Type>()
• Fakes: Prefer Fake{Entity}Repository classes over inline object : Interface for reuse
• One assertion per test (or one logical group)
• No real I/O — mock everything external