What tool or language did you use to write automated tests?

Tools and languages often used for writing automated tests in Java include:

• JUnit — the main framework for unit testing.
• TestNG — an alternative to JUnit with extended capabilities.
• Selenium WebDriver — for automating web interface testing.
• Cucumber — for BDD (behavior-driven development) testing using the Gherkin language.

Example of a simple test in JUnit 5:

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

class CalculatorTest {
    @Test
    void addition() {
        assertEquals(5, 2 + 3);
    }
}