What are some examples of Test-Driven Development in Java?

What are some examples of Test-Driven Development in Java?

Test-Driven Development (TDD) in Java involves writing tests before the actual code. For example, you might start by writing a test for a simple calculator class that adds two numbers.

Can you show me a code example of that?

Sure! Here's a simple example:

import org.junit.Test;
import static org.junit.Assert.*;

public class CalculatorTest {
    @Test
    public void testAdd() {
        Calculator calculator = new Calculator();
        assertEquals(5, calculator.add(2, 3));
    }
}

In this test, we check if the add method returns the correct sum.

What if I want to test a more complex method?

For a more complex method, you can write multiple tests to cover different scenarios. For instance, if you have a method that calculates the factorial of a number, you would write tests for edge cases like 0, 1, and negative numbers.

How do I run these tests in Java?

You can run these tests using a testing framework like JUnit. If you're using an IDE like IntelliJ or Eclipse, you can simply right-click on the test file and select 'Run'. Alternatively, you can run tests from the command line using Maven or Gradle.