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Testing with Robolectric6:41 with Ben Deitch
In this video we'll start testing our project with Robolectric!
We've added a dependency, changed our test runner, and set up the configuration. 0:00 So without further ado, let's get back to testing. 0:05 Unlike Mockito, Robolectric doesn't require us to 0:09 use the view presenter model that we've been using. 0:12 With Robolectric, 0:15 we can just test the activity directly, hence, MainActivityTest. 0:16 Let's start by uncommenting the setUp method and 0:22 deleting everything except activity =. 0:28 Then let's set it equal to Robolectric.setupActivity and 0:33 pass in MainActivity.class for 0:41 the parameter, and that's it. 0:44 Thanks to Robolectric, our activity now exists and 0:49 has gone through the onCreate, onStart and onResume life cycle methods. 0:52 Moving on to the editTextUpdatesTextView test, let's start and 0:59 finish by uncommenting it. 1:03 That button works better for that. 1:11 Then let's run our tests again and, 1:13 yikes, what's this all about? 1:17 Well, it turns out that currently the snapshot build isn't quite ready for 1:27 Marshmallow. 1:32 So let's add back in the Config SDK 1:34 parameter to run on Lollipop instead, 1:38 comma sdk = Build.VERSION_CODES.LOLLIPOP. 1:43 We'll keep using this snapshot build, though. 1:49 It fixes a couple of bugs we would otherwise run into down the road. 1:52 Then let's try running our tests one more time. 1:57 And success! 2:05 But wait, how do we know this is really working? 2:07 Let's comment out the Act line and run it again. 2:10 Just like we would expect, the test now fails because we didn't change the text. 2:22 It still has the default value of textView set in the layout. 2:28 All right, let's uncomment out the Act line and run it again. 2:32 This is what makes Robolectric so powerful. 2:40 We can write our tests as if our app is actually running, even though it's not. 2:43 It just seems that way, thanks to Robolectric. 2:48 Now that we've got our editText tested, let's move on to our spinner. 2:52 Let's create a new @Test method. 2:58 Public void, and let's name it spinnerUpdatesBackgroundColor. 3:07 Which throws an exception. 3:17 Then let's copy and paste in the Arrange, Act, 3:22 Assert comments from the teacher's notes below. 3:24 Cool, starting with the Arrange section, 3:34 it will be exactly the same as it is in MainActivity presenter test. 3:36 So let's just copy and paste it in. 3:41 Moving on to the Act section, we need to select the right item from our spinner. 3:56 Let's type activity.colorSpinner to get our spinner object, 4:01 then let's call the setSelection method and pass in our index. 4:07 Now we just need to assert that the background color is 4:17 equal to our given color. 4:20 But before we get to the Assert statement itself, 4:22 let's create a variable to hold the background color, 4:27 int expectedColor and let's set it equal to 4:32 activity.LinearLayout.getBackground to get the background. 4:36 Then if we open up the quick documentation with Ctrl + J on Mac or 4:43 Ctrl + Q on Windows, 4:48 we can see that the getBackground method will return a Drawable. 4:50 But in our case, we can be a little more specific. 4:57 Since our background is just one solid color, 5:00 instead of Android using the regular Drawable class, 5:04 it uses a specialized version of the Drawable class named ColorDrawable. 5:07 Let's cast this object to a ColorDrawable object, ColorDrawable, 5:14 and then add parenthesis around the whole right side of our statement. 5:19 Then let's call getColor on our newly cast ColorDrawable object. 5:29 And there we go. 5:35 We retrieved the background color from our linear layout and 5:37 stored it in this expectedColor variable. 5:40 To finish up, 5:43 we just need to assert that the given color matches the expected color. 5:44 AssertEquals givenColor, expectedColor. 5:54 All right, now let's comment out the Act section 6:00 And then right-click inside our test method and select Run to run the test. 6:07 And now that we've seen the test fail, let's bring back the Act section and, 6:16 hopefully, we'll see the test pass. 6:20 Nice, with our spinner test out of the way, all that's left is testing that our 6:30 Launch Activity button successfully launches our other activity, 6:34 which we'll get to in the next video. 6:38
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