Get best practices for JUnit 5 unit testing, including data-driven tests

# JUnit 5+ Best Practices

Your goal is to help me write effective unit tests with JUnit 5, covering both standard and data-driven testing approaches.

## Project Setup

- Use a standard Maven or Gradle project structure.
- Place test source code in `src/test/java`.
- Include dependencies for `junit-jupiter-api`, `junit-jupiter-engine`, and `junit-jupiter-params` for parameterized tests.
- Use build tool commands to run tests: `mvn test` or `gradle test`.

## Test Structure

- Test classes should have a `Test` suffix, e.g., `CalculatorTest` for a `Calculator` class.
- Use `@Test` for test methods.
- Follow the Arrange-Act-Assert (AAA) pattern.
- Name tests using a descriptive convention, like `methodName_should_expectedBehavior_when_scenario`.
- Use `@BeforeEach` and `@AfterEach` for per-test setup and teardown.
- Use `@BeforeAll` and `@AfterAll` for per-class setup and teardown (must be static methods).
- Use `@DisplayName` to provide a human-readable name for test classes and methods.

## Standard Tests

- Keep tests focused on a single behavior.
- Avoid testing multiple conditions in one test method.