Using test automation practices to write effective unit tests

Evaluated skills

Write effective unit tests by using test automation best practices

Description

A quiz covering the testing pyramid, basic JUNit unit test structure, annotations, Hamcrest matchers, and interpreting failing tests.

Question 1
Which of the following statements are true of TDD?
Careful, there are several correct answers.
- You to start by writing a failing test before you write your code.
- You start by implementing just enough code to begin writing a test.
- Typically, you should write multiple tests for each method.
- Typically, you should write one unit test per method.

Question 2

Imagine you're working in a small team and a colleague shows you some of their code and review comments. First, you look at the class under test, called Person:

public class Person {
    private String firstName;
    private String lastName;
    
    public Person(String firstName, String lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
    }
    
    public String getFullName() {
        return String.format("%s %s", firstName, lastName);
    }
}

Your colleague shows you their JUnit 4 unit test for this Person class :

import Person;
import org.junit.*;

@RunWith(BlockJUnit4ClassRunner.class)
public class PersonTest {

    // check that person.getFullName() works
    public static void getFullName_shouldReturnTheFirstAndLastName_whenAPersonHasBoth() {
        // Arrange
        String expected = "Katherine Janelay";
        Person personUnderTest = new Person("Katherine", "Janelay");
        // Act
        String fullName = person.getFullName();
        // Assert
        Boolean testIsSuccessful = fullName.equals(expected);
        assert( testIsSuccessful );
        System.out.println("Passed: " + testIsSuccessful );
    }
    
    public static void main(String[] args) {
        getFullName_shouldReturnTheFirstAndLastName_whenAPersonHasBoth();
    }
}

Which of the following comments about this code are correct?

Careful, there are several correct answers.

The runner class should be replaced with JUnitRunner.class.
The @Test annotation is missing.
The assertion method is not suited for testing.
The tests shouldn't be called from the main(String[] args).

Question 3
What is red-green-refactoring?
- A technique to mark code via highlighting. Poor quality code is marked in red, and once fixed, should be marked in green for the code reviewer to check. Fixing your code is called refactoring.
- A technique where you start with a failing test in red, then write code to make it pass to green. You can then improve and modify the code while checking if your changes pass the test via refactoring.
- A testing library that enables you to highlight failing tests in red and passing tests in green. You begin refactoring your code in the failing tests until it turns green.
- A design pattern for a factory class which can start your tests (green) and stop you them (red) so you can take the time to refactor them.

Using test automation practices to write effective unit tests

Evaluated skills

Description

Question 1

Question 2

Question 3