If you're not so

sure you implemented something correctly, it's always a good idea to add some tests.

Let's add tests to our tabloid pile class to let us know if our addCards and

removeCards functions are working like we want them to.

And before I get to that, I want to make sure that this is the addCards function.

Okay, now let's start by first creating a test folder for our project.

First, create just a regular directory named Test in the root of your project.

Then open the project structure window, file, project structure,

and on the Modules tab, select your test folder and mark it as Tests.

Then hit OK and now we've got a spot for our tests.

Next up, let's create the tests.

Click somewhere in your Tableau pile class and then use Command or

CTRL+SHIFT+T and hit Enter to create a new test.

Then for the testing library, make sure you've selected JUnit4 and for

the members, let's pick addCards and removeCards.

Also if you have something up here that says fix, just click on it and

pick the intellijay distribution.

Then hit OK, and now it's testing time.

Remember for each test, we need to do three things.

We need to arrange the objects we need, act on those objects, and

then assert that we got the right result.

So let's start by adding in these steps as comments.

You can find them in the teacher's notes below as well.

All right, let's take it from the top with the addCcards function.

To test that our addCards function is working, we're going to need one Tableau

pile and one mutable list of cards to add to that Tableau pile.

So in the Arrange section, let's start by creating a new Tableau pile.

val tableauPile

= TableauPile.

And then let's initialize our Tableau pile to contain only the King of spades,

mutable list of card with a value of 12 for King and then spades.

On the next line, let's create a new variable for

the cards we're going to add to our Tableau pile.

Val cards and let's set this equal to a list of

one of the cards that would come after this one, or choose the Queen of hearts.

So mutable list of and

then the Queen of hearts, which has a value of 11 and a suit of hearts.

Moving on to the act section,

let's try adding that cards list to our Tableau pile.

tableuPile.addCards and pass in our cards list.

And finally in the assert section, let's check that our Tableau has the right

number of cards which sends red Queen does match with the black King is two.

So assertEquals 2 for the expected value and for

the actual value, tableauPile.cards.size.

Then let's hit the Run button next to our test.

And it looks like the addCards function works, well, at least for those two cards.

Anyhow in the next video, we'll continue the quest for

testing with our removeCards function.