test-create

name: test-create description: Generate unit and integration tests for Java/Kotlin Spring Boot applications using JUnit 5/Kotest + Mockito/MockK. Use when the user asks to "write tests", "create test", "generate test", "add test coverage", or mentions testing specific classes/methods. Supports service tests, controller tests, and test fixtures. disable-model-invocation: true allowed-tools: Read, Write, Edit, Glob, Grep, Bash

Test Generator

Generate comprehensive tests for: $ARGUMENTS

Workflow

Step 1: Analyze Target Code

1. Read the source file to understand:
   • Language (Java or Kotlin)
   • Class type (Controller, Service/UseCase, Repository, Entity)
   • Dependencies (injected fields)
   • Public methods to test

Step 2: Determine Test Location

src/test/
├── java/com/example/app/domain/{domain}/
│   ├── application/usecase/     # UseCase unit tests
│   ├── domain/service/          # Service unit tests
│   ├── presentation/            # Controller tests
│   └── fixture/                 # Test fixtures
└── kotlin/com/example/app/domain/{domain}/
    ├── application/usecase/
    ├── domain/service/
    ├── presentation/
    └── fixture/

Test file naming: {ClassName}Test.{java|kt}

Step 3: Choose Test Style

Decision Guide:

• DescribeSpec: Default choice for service tests. Clean describe/context/it structure.
• BehaviorSpec: Use for complex business logic requiring Given/When/Then BDD style.
• StringSpec: Use for simple validation or property tests.

Step 4: Identify Test Cases

For each public method, create tests for:

• Success case: Valid input, expected output
• Failure case: Invalid input, expected exception
• Edge cases: Empty list, null values, boundary conditions
• Soft delete: Verify deletedAt IS NULL filtering if applicable

Step 5: Generate Test Code

1. Create fixture if needed (in fixture/ directory)
2. Write test class with proper annotations
3. Mock all dependencies
4. Implement test cases following given/when/then pattern
5. Add verification for mock interactions

See detailed examples:

• Java: references/java-examples.md
• Kotlin: references/kotlin-examples.md

Step 6: Run Tests

# Run all tests
./gradlew test

# Run specific test class
./gradlew test --tests "UserGetServiceTest"

# Run tests matching pattern
./gradlew test --tests "*ServiceTest"

# Run with verbose output
./gradlew test --info

Fixture Pattern

Create reusable test data builders in fixture/ directory:

Java:

public class UserTestFixture {
    public static User createUser(Long id, String email) {
        return User.builder()
            .id(id)
            .name("Test User")
            .email(email)
            .status(UserStatus.ACTIVE)
            .build();
    }
}

Kotlin:

object UserTestFixture {
    fun createUser(
        id: Long = 1L,
        email: String = "test@example.com",
        name: String = "Test User"
    ) = User(id = id, name = name, email = email)
}

Controller Tests

Use @WebMvcTest for controller layer tests:

• Mock the UseCase/Service layer
• Test HTTP requests/responses
• Verify JSON serialization
• Check status codes and response structure

See references/java-examples.md and references/kotlin-examples.md for complete examples.

Checklist

Before completing:

• Success case test written
• Failure/exception case test written
• Edge case test written (empty, null, max value)
• Mock verification added (verify)
• Fixture created and reused
• Tests run successfully (./gradlew test --tests "{TestClass}")

Troubleshooting

Test Compilation Errors

Missing imports: Add these dependencies to build.gradle:

testImplementation 'org.springframework.boot:spring-boot-starter-test'
testImplementation 'io.kotest:kotest-runner-junit5:5.x.x'  // Kotlin only
testImplementation 'io.mockk:mockk:1.x.x'                  // Kotlin only

MockK "no answer found" errors

Use relaxed = true for dependencies you don't need to verify:

val repository = mockk<UserRepository>(relaxed = true)

Soft Delete Tests Failing

Ensure repository method includes soft delete filtering:

// Correct
userRepository.findByIdAndDeletedAtIsNull(1L)

// Wrong
userRepository.findById(1L)  // Will include deleted entities

References

• Java Examples (JUnit 5 + Mockito)
• Kotlin Examples (Kotest + MockK)