[MUSIC]

[SOUND] We don't always have the option to build things perfectly the first time,

and we're always learning so that perfect way is going to change.

A great thing about PHPUnit is its wide adoption.

Almost every framework comes shipped with PHPUnit or allows for easy integration.

You can also add PHPUnit as a separate package for

any object oriented application.

Once PHPUnit is installed, you can start adding tests a little bit at a time.

When you need to fix a bug,

unit testing can be used to demonstrate that incorrect functionality.

And then keep that bug from being reintroduced after it's fixed.

When adding a new feature, unit testing can be used to verify the current

functionality before you add new features.

This provides confidence that the new feature

doesn't break the existing functionality.

Let's add PHPUnit to an existing codebase.

I'm going to start with a very basic object oriented project,

a simple cookbook.

There is a lot of functionality that could be added.

But before that,

it would be helpful to make sure that things are working as expected.

To start this process we're going to add PHPUnit and the code dungeon printer.

We could add them one at a time with Composer,

but I'm going to add them directly to a Composer.json file.

Now I can run composer install.

Let's take a look at how this application is put together, I'll open cookbook.php.

This is the main application file.

And we can see that it includes our classes and a recipe file.

These classes are what we'll need for our testing boot strap.

Let's copy those lines and create a new test folder.

Within this folder, we can create a bootstrap.php and we'll paste our lines.

We're going to be adding a phpunit.xml file to our main directory and

calling our test from there.

So these paths will work,

even though the bootstrap file is within the test's folder.

You could also update the paths to be relative to this bootstrap file.

Let's add our phpunit.xml file.

We add PHPUnit and then we're going to add our bootstrap, set this to tests.

Bootstrap.php, turn on our colors,

equals true and set printerClass equals

our Codedungeon PHPUnit,

PrettyResultPrinter\Printer.

Now we're ready to create our first test.

In the test directory, we'll create a new file and

we'll name this RecipesTest.php.

We'll use PHPUnit\Framework\TestCase.

And then we'll add class

RecipesTest extends TestCase.

We're going to create our first test.

We'll set the test and

then we'll name this canBeCreatedWithEmptyTitle,

very descriptive.

Then we'll set recipe equal to new Recipe.

We can then assert that the recipe is an instance of the recipe class.

This assertInstanceOf Recipe.

Recipe.

We can also assert that the title is an empty string.

This assertEquals an empty string and

recipe, getTitle.

Let's run our test.

Vendor/bin/phpunit and our test folder.

Helps if you spell it right.

That's also one reason it's good to copy and paste from the documentation.

But now we can see that we're running our tests.

As we start testing our code, it would be helpful to know which code is tested and

which is not.

Let's set up code coverage.