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

## `[C]`onformance: Conform to a specific format
Many data elements must conform to a specific format. For example, an email address generally follows the form: 
`name@somedomain `

The name and domain portions of the address each follow a different set of fairly detailed rules. Imagine that we want to validate the conformance of an email address to these many regulations.

Perhaps our code parses an email address in an attempt to extract its name portion (the part leading up to the `@ `sign). What we really want to know is what to do if there is no `@` or the name portion is empty.

>**Note:** How to design the code is pretty flexible. You might choose to return a null value or an empty string or even throw an exception. Regardless, we need to write tests that demonstrate what happens when each of these boundary conditions occurs.
 
Validating formatted string data such as email addresses, phone numbers, account numbers, and file names might also involve many rules, but they are usually straightforward. More complex structured data can create a combinatorial explosion of cases to test, however. 

## Testing boundary conditions
Suppose we’re reading report data composed of a header record, some number of data records, and a trailer record. Here are some of the boundary conditions we will need to test:

* No header, just data, and a trailer 
* No data, just a header, and trailer 
* No trailer, just a header, and data 
* Just a trailer 
* Just a header 
* Just data

> It gets easier to brainstorm how data doesn’t conform to the expected structure the more one does it. We’ll find more defects in the process because they often live around the interesting boundaries of our system.

# `[C]`onformance: Conform to a specific format
Many data elements must conform to a specific format. For example, an email address generally follows the form: 
`name@somedomain `

The name and domain portions of the address each follow a different set of fairly detailed rules. Imagine that we want to validate the conformance of an email address to these many regulations.

Perhaps our code parses an email address in an attempt to extract its name portion (the part leading up to the `@ `sign). What we really want to know is what to do if there is no `@` or the name portion is empty.

>**Note:** How to design the code is pretty flexible. You might choose to return a null value or an empty string or even throw an exception. Regardless, we need to write tests that demonstrate what happens when each of these boundary conditions occurs.
 
Validating formatted string data such as email addresses, phone numbers, account numbers, and file names might also involve many rules, but they are usually straightforward. More complex structured data can create a combinatorial explosion of cases to test, however. 

# Testing boundary conditions
Suppose we’re reading report data composed of a header record, some number of data records, and a trailer record. Here are some of the boundary conditions we will need to test:

* No header, just data, and a trailer 
* No data, just a header, and trailer 
* No trailer, just a header, and data 
* Just a trailer 
* Just a header 
* Just data

> It gets easier to brainstorm how data doesn’t conform to the expected structure the more one does it. We’ll find more defects in the process because they often live around the interesting boundaries of our system.

Learn about the principle of conformance in writing unit tests.

[C]ORRECT: [C]onformance

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

[C]ORRECT: [C]onformance

`[C]`onformance: Conform to a specific format

[C]ORRECT: [C]onformance

[C]onformance: Conform to a specific format

`[C]`onformance: Conform to a specific format