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Testing with Robolectric
6:41In this video we'll start testing our project with Robolectric!
We've added a dependency, changed our test
runner, and set up the configuration.
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So without further ado,
let's get back to testing.
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Unlike Mockito,
Robolectric doesn't require us to
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use the view presenter model
that we've been using.
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With Robolectric,
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we can just test the activity directly,
hence, MainActivityTest.
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Let's start by uncommenting
the setUp method and
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deleting everything except activity =.
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Then let's set it equal to
Robolectric.setupActivity and
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pass in MainActivity.class for
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the parameter, and that's it.
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Thanks to Robolectric,
our activity now exists and
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has gone through the onCreate,
onStart and onResume life cycle methods.
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Moving on to the editTextUpdatesTextView
test, let's start and
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finish by uncommenting it.
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That button works better for that.
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Then let's run our tests again and,
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yikes, what's this all about?
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Well, it turns out that currently
the snapshot build isn't quite ready for
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Marshmallow.
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So let's add back in the Config SDK
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parameter to run on Lollipop instead,
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comma sdk = Build.VERSION_CODES.LOLLIPOP.
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We'll keep using this snapshot build,
though.
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It fixes a couple of bugs we would
otherwise run into down the road.
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Then let's try running
our tests one more time.
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And success!
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But wait,
how do we know this is really working?
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Let's comment out the Act line and
run it again.
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Just like we would expect, the test now
fails because we didn't change the text.
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It still has the default value
of textView set in the layout.
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All right, let's uncomment out
the Act line and run it again.
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This is what makes Robolectric so
powerful.
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We can write our tests as if our app is
actually running, even though it's not.
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It just seems that way,
thanks to Robolectric.
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Now that we've got our editText tested,
let's move on to our spinner.
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Let's create a new @Test method.
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Public void, and let's name it
spinnerUpdatesBackgroundColor.
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Which throws an exception.
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Then let's copy and
paste in the Arrange, Act,
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Assert comments from
the teacher's notes below.
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Cool, starting with the Arrange section,
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it will be exactly the same as it
is in MainActivity presenter test.
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So let's just copy and paste it in.
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Moving on to the Act section, we need to
select the right item from our spinner.
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Let's type activity.colorSpinner
to get our spinner object,
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then let's call the setSelection
method and pass in our index.
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Now we just need to assert
that the background color is
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equal to our given color.
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But before we get to
the Assert statement itself,
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let's create a variable to
hold the background color,
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int expectedColor and
let's set it equal to
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activity.LinearLayout.getBackground to
get the background.
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Then if we open up the quick
documentation with Ctrl + J on Mac or
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Ctrl + Q on Windows,
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we can see that the getBackground
method will return a Drawable.
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But in our case,
we can be a little more specific.
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Since our background is
just one solid color,
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instead of Android using
the regular Drawable class,
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it uses a specialized version of
the Drawable class named ColorDrawable.
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Let's cast this object to
a ColorDrawable object, ColorDrawable,
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and then add parenthesis around
the whole right side of our statement.
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Then let's call getColor on our
newly cast ColorDrawable object.
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And there we go.
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We retrieved the background
color from our linear layout and
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stored it in this expectedColor variable.
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To finish up,
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we just need to assert that the given
color matches the expected color.
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AssertEquals givenColor, expectedColor.
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All right,
now let's comment out the Act section
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And then right-click inside our test
method and select Run to run the test.
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And now that we've seen the test fail,
let's bring back the Act section and,
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hopefully, we'll see the test pass.
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Nice, with our spinner test out of the
way, all that's left is testing that our
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Launch Activity button successfully
launches our other activity,
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which we'll get to in the next video.
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