Original subtitles

Now that we have managed to load a custom raised button with the pump we did mattered.

We can start doing something interesting with it.

And for example we could check that this widget has a raised button inside it and to do that we need

to use an object which is called a finder.

So over here we can type the final button equals find.

And here we get a list of all the metals that we can use to find a widget.

And the one that we want is find by type like this.

And so here we can pass braised bottom as an argument and then we need to write an expectation.

So here I can type expect that button and then I'm going to use something that is called a matter.

And in this case I can type finds one widget like this and finds one way that is a specific matter that

is defined in the flatter test package.

So in a nutshell this code tries to find a widget of type raised button inside the widget 3 that is

returned by the custom raised but the widget.

And then we expect that we find exactly one match by using this matter constant.

So let's run the tests again OK.

So let's get some more practice using matters by writing another expectation.

And here I could dive extract and then find that y type.

And this time I is flat bottom and then I want my matter to be fines nothing like this and finds nothing

is a very common matter that is used to check that no we just are fun.

So I could run the tests again and what we are saying here is that we expect to find our raised button

but not a flat bottom.

And our tests have passed again.

OK.

So let's take things one step further.

And as you can see this custom raised button takes an optional child.

We did and this is normally used to add some text inside a button.

So as our next step we cannot a child.

We did when we create this button and here we can pass up the text.

We did that says stop me for example.

And if we want here we can right expect and then find and this time we can say text and we're going

to use the same string.

So to me like this and we are going to use finds one widget as a matter.

So let's run this test again.

And the idea here is that we can pass a custom child to our widget and because this is a text widget

then we can find that we did with the text that was used to configure it.

And once again our test is green.

In summary we have discovered how we can check if a widget contains another widget either white type

or with a specific text.

And to do that we need to use finders and matters.

So let's continue on the next video.