Controller Testing

You've had a chance to see the code base so it's time we dive into some testing. 0:00 Now whereas the code you've explored so 0:03 far resides in the main source directory, the code that we'll write during 0:05 this workshop will live in the test source directory, so let's open that now. 0:09 In here there's exactly one package com. 0:13 teamtreehouse.web.controller and in that package one class weather controller test. 0:16 Let's open that now. 0:22 What I'll do in this workshop is show you how to test spring 0:23 components starting with the controller like this one then 0:26 working our way towards the database by moving to services and finally to DAO's. 0:29 Let's begin by testing the weather controller in this class weather 0:34 controller test. 0:37 Now for each method in a controller we'd want to write at least one test and 0:38 even more if we have boundary cases to consider. 0:43 Remember those are the special cases that won't happen often or maybe hardly ever. 0:45 But we want to make sure application doesn't blow up 0:50 in the event that the unlikely occurs at any rate. 0:52 Let's start by testing this controller for 0:56 what happens when the home page is requested. 0:58 So if we open the weather controller. 1:01 And scroll down to where the home page is requested which is at the bottom here. 1:06 We see that the only thing that this method does is render 1:12 the weather/detail template. 1:15 So let's make sure it does just that. 1:18 First though, we need to set up our mock environment. 1:20 So back in WeatherControllerTest, 1:24 we are going to have to set up our mock environment. 1:25 Now typically when we run a spring application, the overall shell or 1:28 container that we are starting is called an application context. 1:31 This is a spring container that loads and manages bean definitions, 1:37 like the methods that you've annotated with bean in your config files. 1:40 Or all those classes you've annotated with controller, service, repository, and 1:44 component. 1:49 Now, all of this is a bit overkill for our unit test. 1:50 That is, loading all these definitions. 1:53 We don't need all those being definitions and the extra functionality provided by 1:55 the application context just for testing purposes. 1:58 If we were to load the context, that would be an integration test. 2:02 Integration tests are important but they are not the subject of this workshop. 2:06 Be sure to check the teacher's notes for more on the spring application context. 2:10 Instead of loading an entire application context here, what we'll do is create 2:15 a fake or mock MVC object through which we can run all requests to our application 2:19 and we won't need to fire up the entire context which would take more time anyway. 2:24 So to begin, let's set up a mock MVC object. 2:29 I'll declare it as a field so I can reuse it within the individual test methods. 2:32 Private MockMVC, there it is right there, and I'll call it mockMVC. 2:36 We'll also need a controller to set up that mocked MVC framework, so 2:44 let's declare one of those too. 2:47 Private WeatherController that's our controller under test here and 2:48 I'll just name that controller. 2:52 As you've seen with unit testing in the past we can include a method in J Unit 2:56 tests that is sure to execute once before each of the test methods is executed. 3:01 Let's use that method to set up our controller and mock NBC objects. 3:06 So public void, I'll name it setup, that's the standard name for 3:10 one of these methods. 3:14 And let's set up the controller. 3:15 So I'll create a new weather controller excellent. 3:18 And let's also set up the mock MVC object. 3:22 Now this object is set up with the builder pattern so 3:25 mock MVC builders right here and will choose the standalone set up and 3:29 pass to it the controller that we just created and 3:34 to build the object and store it into the mock MVC field. 3:39 I will call this builders build method. 3:42 Okay, time to write our first test. 3:45 Again, we wanna test that a request to our home page renders the weather detail view. 3:48 Let's name our method accordingly. 3:52 I'll annotate this with J units test annotation and I'll call it public void. 3:54 And the home should render the detail view. 4:01 And I'll say it throws an exception. 4:05 As for the test code, we'll start by using the mockMvc object to perform a get 4:11 request, so mockMvc.perform And 4:15 what we can do here is use the mock N.B.C. request builder's class. 4:21 So if you arrow down there you see it right there and 4:25 we'll use the get method and in parentheses here the parameter 4:29 value we want to pass is the U.R.I. that we'd like to perform a get request to. 4:34 Now for convenience, let's do a static import of this 4:39 mockMvcRequestBuilders class, all of its methods. 4:43 So here we have that right here. 4:48 I'm going to move this down here and 4:52 do an import static of all its methods. 4:56 And I'll be sure to change that second import statement to static. 5:02 Cool. 5:08 Now I can remove this right here, and 5:10 that get method is called in a much more succinct 5:13 after this call to the mock NBC's perform method, we can write 5:19 expectations which are like assertions by chaining method calls right here. 5:22 For example, let's expect that the view name is weather slash detail. 5:27 So we'll write andExpect. 5:32 And in here, we can use a MockMvcResult matcher and 5:35 all say that it's view name so, view it's 5:41 name is equal to weather/detail. 5:47 Let me put this on a couple lines so you can see it in my code window here. 5:52 Give us a little more room there we go let's do that right there. 5:58 Okay, let's do the same thing for this mock NBC result matchers methods 6:05 as we did for the mock NBC request builders right here. 6:10 So I'm going to move that down here under my static imports. 6:13 So import static will say all its methods and 6:19 I can get rid of this using its static methods quite a bit. 6:24 So this allows us to write much shorter code and 6:29 just like that we have our first test. 6:33 Now let's run it. 6:35 I'll make sure to save my file here. 6:38 And with the weather controller test editor in focus all use 6:40 control shift R to run this test. 6:45 What you should get is a panel that pops up at the bottom showing the success or 6:49 failure of this test. 6:53 And great looks like our test Passes, we got green. 6:56 Let me show you one more test before we start looking at mocking objects. 7:02 Let's test the weather controller's search method. 7:06 So, back in the weather controller class, 7:09 let's see what the search method does here. 7:11 The method currently accept a URL query string parameter and 7:15 redirects to a URI with a path parameter. 7:19 Let's make sure in our tests that this actually happens. 7:24 So let's go back to the test. 7:27 I'll start by stepping out a method according to what I'd like the test to 7:30 examine. 7:33 So let's write a second test down here. 7:34 I'll name this one public void search_ShouldRedirectWithPathParam(). 7:38 Cool, and in that method, let's perform 7:52 a get request to the /search URI, so mockMvc.perform. 7:56 And again this is a GET request to the slash search you are I 8:02 know what we need to do is we need to add to that query string parameter to the GET 8:10 request so after the call to get I will call the param method. 8:14 The parameter name is q and the value I'd like to pass is 60657 and 8:19 what we expect is that this request 8:25 redirects to /search/60657. 8:29 So let's do that now let me put this on the next line here .andExpect. 8:35 I will say redirectedUrl. 8:42 That's another method that comes from this MockMvcResultMatchers class. 8:46 So I want to expect that the redirected URL is /search/60657. 8:51 I'll put my semi colon at the end here. 8:59 There are lots of things that you can include as an expectation. 9:02 Check the teacher's notes for more. 9:05 Okay, let's run both these tests and see if we're still in the green, 9:09 control shift r and let's watch both of our tests run and hopefully succeed. 9:12 Excellent, it says all two tests have passed and I see the names of those tests. 9:19 Right here. 9:24 Now, though we're green, we've only just begun. 9:27 Next I'll introduce you to the powerful world of mocking. 9:29 No I don't mean giving other people hard time. 9:33 I mean faking objects. 9:36 You'll see what I mean. 9:38