Explore writing unit tests for Java applications using JUnit, delve into JUnit organization, assertions, quality practices, design relevance, refactoring, and using mock objects for dependencies.

Pragmatic Unit Testing in Java 8 with Junit by The Pragmatic Programmer.png

junit.tar.gz

java

test2

test4 - Our first passing test

test6

test14

test16-branch-persistence

AssertTest-13

test15

test15-profile

test15-ProfilePoolTest

test16-BearingTest

test16-RectangleTest

test16-SparseTest

test16-TransmissionTest

test16-ProfileTest

test20m-ProfileTest

test21-Profile

big1-Profile

big1-MatchSet

big4-MatchSetTest

big4-MatchSet

big6

mock-2-AddressRetrieverTest

mock-4-AddressRetrieverTest

mock-5-AddressRetrieverTest

test1-SearchTest

test3-SearchTest

tdd-1-ProfileTest.java 

tdd-2-ProfileTest.java

tdd-3-ProfileTest.java

tdd-4-Profile.java

tdd-5-ProfileTest.java

tdd-9-ProfileTest.java

tdd-10-ProfileTest.java

tdd-10-AnswerTest.java

tdd-11-ProfileTest.java

tdd-12-ProfileTest.java

tdd-14-ProfileTest.java

tdd-15-ProfileTest.java

thread-2-ProfileMatcherTest

thread-3-ProfileMatcherTest

thread-4-ProfileMatcherTest

test16-branch-persistence-redesign-QCTest

AssertHamcrest-13

test16-branch-persistence-redesign-StatCompilerTest

test16-ProfilePoolTest

test15-ProfilePoolTest-copy 16

test3-SearchTest-ContainsMatches

tdd-11-ProfileTest.java-Supporting Multiple Answers

thread-2-ProfileMatcherTest-Testing Multithreaded Code

test2-Our First passing test

test4 - AAA your way to a test

test2-final-intro-junit

In this course, you will learn how to write a unit test for Java applications using JUnit. You'll start by covering unit-testing foundations, which provide you with a starter set of information about writing basic tests in JUnit. You’ll learn about JUnit organization and assertions, and you’ll pick up a few core quality practices for unit testing such as the Right BICEP and the CORRECT way. 

Towards the end, the bigger design picture focuses on the relevance of design to unit testing and vice versa. You’ll refactor your tests, and you’ll learn how to use mock objects to deal with trouble-some dependencies.

Pragmatic Unit Testing in Java 8 with JUnit

# All green, all of the time!
We should normally expect that all our tests pass all of the time. In practice, that means that when we introduce a bug, only one or two tests fail. Isolating the problem is usually pretty easy in such an environment.

![](/api/collection/10370001/4926514153390080/page/4609781890809856/image/6411810401419264)

> Do not continue adding features when there are failing tests! Fix any test as soon as it fails, and keep all tests passing all of the time. “All green all of the time!” will keep us sane when we must change production code.

# Reducing the tests
While it can seem more efficient, there are downsides to limiting the number of tests we run: 
* The longer we go without the feedback that our entire suite of tests provides, the more likely we are to write code that breaks something else in our application.

* Finding the problem later can cost us significantly more time than finding it immediately.
 

# How fast can we run tests?

If our tests don’t interact with code that controls slow resources like databases, it’s possible to run thousands of tests in a few seconds. At that speed, the easiest thing to do is to run all our tests all the time.

Learn about how to make tests fast and pass.

Green Is Good

Before We Begin

JUnit Test Foundations

Digging Deeper into JUnit Assertions

Organizing Your Tests

Mastering Manic Mnemonics!

What to Test: The Right-BICEP

Boundary Conditions: The CORRECT Way

The Bigger Design Picture

Bigger Design Issues

Using Mock Objects

Refactoring Tests

The Bigger Unit-Testing Picture

Testing Some Tough Stuff

Testing on a Project

Wrapping Up

Appendix - Setting up JUnit

Green Is Good

All green, all of the time!