1 00:00:02,190 --> 00:00:08,340 Now of course there is more we could test on our off middleware but I'd say we tested it quite extensively 2 00:00:08,400 --> 00:00:14,070 thus far and therefore I want to move on and I want to move on to our controllers which of course also 3 00:00:14,280 --> 00:00:17,500 house a lot of our core logic. 4 00:00:17,610 --> 00:00:19,650 There we have that off controller. 5 00:00:19,650 --> 00:00:25,140 Obviously we have that feed controller now for that feed controller. 6 00:00:25,140 --> 00:00:28,660 We have routes where we need to be authenticated. 7 00:00:28,680 --> 00:00:32,160 We have a look at our routes here for getting posts. 8 00:00:32,160 --> 00:00:37,370 For example we need to be authenticated for creating posts. 9 00:00:37,380 --> 00:00:41,750 We need to be authenticated essentially for all our post related rulings. 10 00:00:41,760 --> 00:00:48,080 We need to be authenticated and before we take care about that let's have a look at our off controller. 11 00:00:48,090 --> 00:00:54,090 Therefore because these routes don't require us to be authenticated though does it really matter too 12 00:00:54,090 --> 00:00:56,040 much as to question. 13 00:00:56,040 --> 00:01:02,710 Well let's have a look at how we reach our controller functions here like sign up or log in. 14 00:01:02,790 --> 00:01:09,030 We of course reached them through our routes which are defined in the routes folder where we send requests 15 00:01:09,060 --> 00:01:09,750 to India. 16 00:01:09,840 --> 00:01:12,780 So these are the API and points we're exposing here. 17 00:01:13,080 --> 00:01:15,080 And now what did I mentioned earlier. 18 00:01:15,120 --> 00:01:17,070 What what are we testing. 19 00:01:17,070 --> 00:01:18,840 Well we are writing units tests. 20 00:01:18,840 --> 00:01:23,880 We are testing units in our code just as the middleware do you off middleware. 21 00:01:23,880 --> 00:01:30,210 And therefore what will not test is the routing here will not test whether we can send a request to 22 00:01:30,210 --> 00:01:38,370 log in and we execute the log in function in the off controller because that entire for warding off 23 00:01:38,370 --> 00:01:41,880 the request the execution of this method here. 24 00:01:41,910 --> 00:01:43,940 That is all handled by express. 25 00:01:44,050 --> 00:01:48,550 And as I mentioned earlier you don't want to test our libraries. 26 00:01:48,570 --> 00:01:50,520 You want to test your own code. 27 00:01:50,520 --> 00:01:56,790 So we absolutely don't need to test this flow and therefore we'll just test these controller functions 28 00:01:56,790 --> 00:02:00,550 we export here like the sign up or to log in function. 29 00:02:00,570 --> 00:02:06,240 These are the things we want to test now when they're there of course again is a broad variety of things 30 00:02:06,240 --> 00:02:07,170 we can test. 31 00:02:07,260 --> 00:02:14,100 We can test whether we're able to extract e-mail and password from the incoming request though that's 32 00:02:14,100 --> 00:02:19,020 a test that's not too useful because we will simulate the request that's coming in. 33 00:02:19,020 --> 00:02:24,840 So we decide whether that is set or not but we can then test if it behaves correctly if no e-mail is 34 00:02:24,840 --> 00:02:30,560 set for example or if we already have a user with that e-mail. 35 00:02:30,810 --> 00:02:34,530 However there is one new complexity added. 36 00:02:34,530 --> 00:02:42,960 Now we have a database now we're interacting with the User model here and the User model of course is 37 00:02:42,960 --> 00:02:45,240 based on our Mongoose models here. 38 00:02:45,240 --> 00:02:51,840 That's our user model and that behind the scenes uses Mongo D.B. and that of course brings one important 39 00:02:51,840 --> 00:02:57,150 question to the focus how can we test our database. 40 00:02:57,150 --> 00:02:59,920 How can we handle this now. 41 00:03:00,070 --> 00:03:03,990 And turns out there are two main strategies we can follow. 42 00:03:03,990 --> 00:03:11,850 So let's have a look at both strategy number one for testing code that involves database operations 43 00:03:12,270 --> 00:03:22,810 is that we stub or mock the parts that actually rely on database access and what would this mean. 44 00:03:22,830 --> 00:03:31,200 This could mean for example that here when we execute find one we again create a step that returns a 45 00:03:31,200 --> 00:03:34,840 predefined result and we then test if our code behaves correctly. 46 00:03:35,340 --> 00:03:44,070 So for example we might be interested here in finding out how our code behaves when find one frozen 47 00:03:44,130 --> 00:03:44,670 error. 48 00:03:44,670 --> 00:03:52,350 So if we're having trouble interacting with the database or how our code behaves if we don't have a 49 00:03:52,350 --> 00:03:55,420 user with that e-mail address when logging in. 50 00:03:55,530 --> 00:03:59,160 These are two different scenarios and we can write two different tests for that. 51 00:03:59,160 --> 00:04:02,540 Both scenarios should actually throw an error eventually. 52 00:04:02,550 --> 00:04:09,420 Here we throw one manually and if find one fails it also will throw an error but the status code for 53 00:04:09,420 --> 00:04:11,040 example should be different. 54 00:04:11,040 --> 00:04:17,520 The status code should be 500 if the database fails because we use our default code then or we set our 55 00:04:17,520 --> 00:04:18,800 own 401 code. 56 00:04:18,810 --> 00:04:24,900 If we have no user now to test us all first of all create a new file in the test folder and I will named 57 00:04:24,900 --> 00:04:34,080 as of controller dot J.S. and in there just as in the off middleware file I'll import expect from China 58 00:04:34,860 --> 00:04:42,180 and I'll also import sign then because I will start with stubbing that post to find one method that 59 00:04:42,180 --> 00:04:49,740 of course add that user find one method therefore I will also import the user by requiring it from the 60 00:04:49,740 --> 00:04:56,340 user model file just as I'm doing it here in the off controller there we are also importing the user 61 00:04:56,340 --> 00:04:57,750 model. 62 00:04:57,750 --> 00:05:02,670 So now I want to test and log in function and since I want to test that function we need to import this 63 00:05:02,670 --> 00:05:11,010 year as well or in general I'll import my off controller by requiring it from the off file and the controllers 64 00:05:11,010 --> 00:05:12,640 folder. 65 00:05:12,800 --> 00:05:22,310 Now let's add of the scribe block maybe where we test our off controller log in process because even 66 00:05:22,310 --> 00:05:27,380 if we're only testing the off controller in this entire file we might be testing different parts of 67 00:05:27,380 --> 00:05:30,110 that controller like log in and sign up and so on. 68 00:05:30,140 --> 00:05:41,330 So you're old start with log in and then here I want to start by stopping my find one method because 69 00:05:41,340 --> 00:05:46,860 that's the first tactic we can apply we can simply stop that a ways that we don't make a real database 70 00:05:46,860 --> 00:05:47,880 access. 71 00:05:48,150 --> 00:05:56,430 So here what we can do is of course I can again use sign and create a stub create that on the user object 72 00:05:56,610 --> 00:05:58,740 for to find one method 73 00:06:01,550 --> 00:06:05,020 now if I want to you forced us to throw an error. 74 00:06:05,030 --> 00:06:13,590 I can then call the user find one throats now here does will throw an error now by the way. 75 00:06:13,590 --> 00:06:16,710 Of course one issue I have here is that I'm into the scribe blog. 76 00:06:16,710 --> 00:06:20,840 This should go into an IT block that was so into an actual test case. 77 00:06:20,880 --> 00:06:29,350 So here it should flow an hour or if accessing the database fails. 78 00:06:29,370 --> 00:06:31,800 For example. 79 00:06:31,880 --> 00:06:37,010 So now here in that function we define our actual test code and there we set up that stub. 80 00:06:37,200 --> 00:06:43,340 And the important thing here of course is I'm faking that data base fail because I completely replace 81 00:06:43,340 --> 00:06:49,310 to find one method with a stop that will throw an error because the actual thing I wanna check is of 82 00:06:49,310 --> 00:06:52,970 course that we should throw an error with code 500. 83 00:06:52,970 --> 00:06:59,150 So I want to check whether our default status code down there really gets applied correctly. 84 00:06:59,210 --> 00:07:06,470 Now back in the off controller in the end I also want to call restore here. 85 00:07:06,550 --> 00:07:16,480 But in between I of course want to define my expectation and the expectation here is that for my off 86 00:07:16,480 --> 00:07:24,510 controller the log in method when that gets called that it actually throws an error. 87 00:07:24,520 --> 00:07:30,070 Now for that let's have a look at the off controller again and you should now recognize that we have 88 00:07:30,070 --> 00:07:32,080 to async keyword in front of that. 89 00:07:32,290 --> 00:07:38,030 It's not a normal function it's an async function and that means in the end we use promises in there. 90 00:07:38,080 --> 00:07:43,600 You might remember async await is just a more elegant syntax for using promises. 91 00:07:43,630 --> 00:07:49,240 So actually we have a synchronous code in here which is a navigate complexity will have to deal with 92 00:07:49,600 --> 00:07:55,100 because the execution of that code will not happen synchronous. 93 00:07:55,210 --> 00:08:01,080 And that means that by default our expectation you won't work the way you might expect it to work.