1
00:00:00,330 --> 00:00:04,531
We just changed our app to include
a new interface and a new class.

2
00:00:04,531 --> 00:00:07,880
And we're almost ready to
take another shot at testing.

3
00:00:07,880 --> 00:00:11,590
But first let's take a look back at
what we accomplished in the last video.

4
00:00:13,270 --> 00:00:17,910
We started by creating the
MainActivityView interface, which defines

5
00:00:17,910 --> 00:00:22,686
all the actions we can take that affect
the UI, changing the TextViewText,

6
00:00:22,686 --> 00:00:27,490
changing the BackgroundColor,
and launching the OtherActivity.

7
00:00:27,490 --> 00:00:31,060
We also created
the MainActivityPresenter class.

8
00:00:31,060 --> 00:00:34,550
This class is responsible for
presenting the view and

9
00:00:34,550 --> 00:00:39,060
is the only class allowed to call methods
defined in our MainActivityView interface.

10
00:00:40,360 --> 00:00:42,420
To make this work with our activity,

11
00:00:42,420 --> 00:00:47,670
we start by making our activity implement
the MainActivityView interface.

12
00:00:47,670 --> 00:00:51,150
Then we initialize our
MainActivityPresenter, and

13
00:00:51,150 --> 00:00:53,100
whenever an action occurs,

14
00:00:53,100 --> 00:00:57,230
like a user clicking the launch activity
button, we let the presenter handle it.

15
00:00:58,460 --> 00:01:02,740
This way of organizing the app
makes it a lot easier to unit test.

16
00:01:02,740 --> 00:01:07,880
Now instead of checking the text of the
text view directly, we can just check and

17
00:01:07,880 --> 00:01:11,300
make sure that our presenter
is calling changeTextViewText

18
00:01:11,300 --> 00:01:13,180
with the right argument.

19
00:01:13,180 --> 00:01:15,980
We don't need to involve
the activity at all.

20
00:01:15,980 --> 00:01:19,590
We just need to test that when we
call a method on the presenter,

21
00:01:19,590 --> 00:01:21,420
it calls the right method on the view.

22
00:01:23,000 --> 00:01:30,036
So instead of testing MainActivity,
let's instead test MainActivityPresenter.

23
00:01:30,036 --> 00:01:34,860
Right-click, Go To > Test.

24
00:01:34,860 --> 00:01:35,780
Create New Test.

25
00:01:37,600 --> 00:01:40,354
Then let's check the box for
a setUp method and

26
00:01:40,354 --> 00:01:44,031
check these boxes to make it
generate all three test methods.

27
00:01:47,197 --> 00:01:50,764
Then hit OK and
make sure to pick the test directory and

28
00:01:50,764 --> 00:01:53,002
not the androidTest directory.

29
00:01:53,002 --> 00:01:56,962
The androidTest directory is for
tests that run on an actual device.

30
00:01:59,496 --> 00:02:01,117
Once our tests are generated,

31
00:02:01,117 --> 00:02:04,868
let's quickly change the test methods
to not start with the word test.

32
00:02:12,996 --> 00:02:16,016
Then, since we'll be using our presenter,

33
00:02:16,016 --> 00:02:20,636
let's create a new MainActivityPresenter
field named presenter.

34
00:02:25,356 --> 00:02:28,214
But before we can
initialize this presenter,

35
00:02:28,214 --> 00:02:30,370
we will need a MainActivityView.

36
00:02:30,370 --> 00:02:36,320
Let's create a new field for
a MainActivityView and name it view.

37
00:02:37,690 --> 00:02:42,490
Right now the only main activity
view we have is main activity,

38
00:02:42,490 --> 00:02:44,180
which we're trying to avoid using.

39
00:02:45,540 --> 00:02:50,691
So let's instead create a new
inner class named MockedView and

40
00:02:50,691 --> 00:02:55,077
make it implement our
MainActivityView interface.

41
00:02:57,726 --> 00:02:59,740
And Alt+Enter to add the methods.

42
00:03:02,160 --> 00:03:04,984
Now that we've got MockedView
as an inner class,

43
00:03:04,984 --> 00:03:08,090
in the setPp method let's
initialize our view field.

44
00:03:10,140 --> 00:03:13,295
view = new MockedView, and

45
00:03:13,295 --> 00:03:18,821
then use this field to
initialize our presenter.

46
00:03:18,821 --> 00:03:25,114
presenter = new MainActivityPresenter and
passing in our view.

47
00:03:26,976 --> 00:03:29,610
All right, we're all set up.

48
00:03:29,610 --> 00:03:31,810
Let's start with the editTextUpdated test.

49
00:03:33,000 --> 00:03:35,265
First we need to arrange the test.

50
00:03:40,375 --> 00:03:43,856
Let's create a new string
variable named givenString and

51
00:03:43,856 --> 00:03:46,210
set it equal to "test123" again.

52
00:03:48,810 --> 00:03:52,093
Then we need to act.

53
00:03:52,093 --> 00:03:55,632
Let's type presenter.editTextUpdated and

54
00:03:55,632 --> 00:04:00,628
pass in our string to simulate
the user submitting the edit text.

55
00:04:04,986 --> 00:04:10,060
Lastly we need to assert that we got
the right outcome, meaning we need

56
00:04:10,060 --> 00:04:15,134
to check that the value we passed into
our presenter is the same value we

57
00:04:15,134 --> 00:04:20,080
got passed into the changeTextViewText
method of our MockedView.

58
00:04:20,080 --> 00:04:24,225
To do this let's create a new string
field in our MockedView class,

59
00:04:27,816 --> 00:04:30,002
And name it textViewText.

60
00:04:33,521 --> 00:04:37,046
Then, in the changeTextViewText method,

61
00:04:37,046 --> 00:04:42,770
let's update our new TextViewText
field to equal the text parameter.

62
00:04:44,700 --> 00:04:48,158
Now back in the editTextUpdated method,

63
00:04:48,158 --> 00:04:52,716
let's add a line at the bottom and
type assertEquals.

64
00:04:56,063 --> 00:05:00,607
And then for the expected result,
let's pass in givenString.

65
00:05:00,607 --> 00:05:04,809
And for the actual result, let's pass
in the TextViewText field from our

66
00:05:04,809 --> 00:05:08,085
MockedView, which we'll need
to cast to a MockedView.

67
00:05:09,820 --> 00:05:15,757
((MockedView), casting
our view to a MockedView,

68
00:05:15,757 --> 00:05:18,670
and then .textViewText.

69
00:05:21,411 --> 00:05:23,340
Great work!

70
00:05:23,340 --> 00:05:26,612
Now let's right-click
inside this method and

71
00:05:26,612 --> 00:05:30,627
pick Run 'editTextUpdated()' and
see what happens.

72
00:05:30,627 --> 00:05:31,427
Woohoo!

73
00:05:31,427 --> 00:05:33,490
We passed!

74
00:05:33,490 --> 00:05:38,120
Now I know some of you are probably
thinking that this doesn't really count.

75
00:05:38,120 --> 00:05:41,690
And I'll admit that it
does look a bit trivial.

76
00:05:41,690 --> 00:05:45,060
But if you think about it, we've tested
everything that we need to test for

77
00:05:45,060 --> 00:05:46,590
our edit text.

78
00:05:46,590 --> 00:05:53,410
On the front-end, we don't need to test
that the OnEditorAction method works.

79
00:05:53,410 --> 00:05:57,550
We just need to drop in a call
to presenter.editTextUpdated and

80
00:05:57,550 --> 00:06:00,190
trust that the Android
system works as advertised.

81
00:06:01,260 --> 00:06:04,512
Similarly, after introducing the view and
presenter,

82
00:06:04,512 --> 00:06:07,840
we don't actually need to check
the text in our text view.

83
00:06:10,076 --> 00:06:13,519
We just need to check that
changeTextViewText was called with

84
00:06:13,519 --> 00:06:15,490
the right value.

85
00:06:15,490 --> 00:06:19,750
We can trust that this textView.setText
line works as expected.

86
00:06:21,090 --> 00:06:22,040
We did it.

87
00:06:22,040 --> 00:06:25,015
We restructured our project
to be more testable and

88
00:06:25,015 --> 00:06:27,239
implemented a test using only JUnit.

89
00:06:27,239 --> 00:06:31,057
In the next video we'll see how we can
start to simplify things by making use of

90
00:06:31,057 --> 00:06:33,481
a very popular mocking
framework called Mockito