1 00:00:02,270 --> 00:00:07,310 I kind of answered why we want a test already but I would really want to make this clear again. 2 00:00:07,430 --> 00:00:14,540 Testing so and with that I mean automated tests allows us to automatically test everything and there 3 00:00:14,540 --> 00:00:19,940 is a star behind that because we only test what we define so only the tests we write. 4 00:00:20,000 --> 00:00:23,810 But in theory it allows you to test everything in your application. 5 00:00:23,870 --> 00:00:30,980 After every code adjustment after every code change therefore it's easy to detect breaking changes even 6 00:00:30,980 --> 00:00:35,700 in places you might not have expected to rig upon your latest change. 7 00:00:35,930 --> 00:00:42,430 And with automated tests we ensure that we have predictable clearly defined testing steps. 8 00:00:42,710 --> 00:00:49,070 Our tests obviously always run in the exact same ways and we define all the steps in code and that of 9 00:00:49,070 --> 00:00:53,610 course ensures that we can rely on the scenario always being the same. 10 00:00:53,660 --> 00:00:57,980 If you are manually testing your app you might think you're doing the same thing as you did the last 11 00:00:57,980 --> 00:00:58,550 time. 12 00:00:58,550 --> 00:01:02,600 But in reality you might not be doing that because you forgot a step. 13 00:01:02,690 --> 00:01:04,330 So that is why you should test. 14 00:01:04,370 --> 00:01:12,160 How do you then set up your node project for testing no matter what you're building with node jars. 15 00:01:12,180 --> 00:01:17,310 So no matter if you're building a page where you render the use on the server if you are building a 16 00:01:17,310 --> 00:01:23,600 REST API or if you're building a graph El API you want to run tests automatically. 17 00:01:23,630 --> 00:01:29,350 So you want to run code that tests your code and verdad you typically need a couple of tools. 18 00:01:29,520 --> 00:01:32,560 You need a tool that executes your test code. 19 00:01:32,730 --> 00:01:37,410 Sounds pretty simple but you need that and it should not only execute your code. 20 00:01:37,410 --> 00:01:44,070 It should also give you a nice output that tells you whether your tests all pass or if a test failed. 21 00:01:44,070 --> 00:01:46,570 So that is the first tool we need. 22 00:01:46,650 --> 00:01:52,290 The second tool then is one that does not just run our code but that also allows us to define certain 23 00:01:52,290 --> 00:01:54,240 conditions that have to be met. 24 00:01:54,270 --> 00:02:00,020 So we want to assert certain results we want to find out if certain scenarios. 25 00:02:00,360 --> 00:02:02,550 Well succeeded if test succeeded. 26 00:02:02,550 --> 00:02:06,420 We wanted to find what success means in a certain test. 27 00:02:06,420 --> 00:02:09,540 So we want to validate the test outcome. 28 00:02:09,540 --> 00:02:14,190 Now for running the tests there are different tools for all these steps but for running these tests 29 00:02:14,520 --> 00:02:18,660 one popular framework is mocha and we'll use mocha. 30 00:02:18,660 --> 00:02:26,160 In this module here too and for asserting the results and defining conditions Chai is a popular choice 31 00:02:26,160 --> 00:02:28,970 and we'll use that in this module too. 32 00:02:28,980 --> 00:02:34,740 There are alternatives like just but mocha and Chai are really popular exist for a long time. 33 00:02:34,740 --> 00:02:40,640 There are a lot of tutorials out there for you to dive deeper and therefore I will also use them here. 34 00:02:40,650 --> 00:02:44,400 You're certainly not doing anything wrong when sticking to these tools. 35 00:02:44,400 --> 00:02:50,970 Now as you will see for this module there will also be one ever tool we need when it comes to managing 36 00:02:50,970 --> 00:02:58,380 side effects or working with external dependencies or certain complex scenarios. 37 00:02:58,380 --> 00:03:05,370 There will use sign on which is a tool that allows us to create steps or marks and I will come back 38 00:03:05,370 --> 00:03:07,420 to what that is later. 39 00:03:07,440 --> 00:03:13,470 Now with that all out of the way I'd say let's install our basic testing tools and let's set up our 40 00:03:13,710 --> 00:03:20,100 testing environment and then also write our first test so that we can gradually walk through our node 41 00:03:20,100 --> 00:03:23,220 application and see how we could test it.