Different Types of Testing

The kind of automated test we'll learn to write in this course 0:00 are called, Unit Tests. 0:03 Unit Testing involves Writing tests that confirm an individual function or 0:05 piece of code works the way we want it to. 0:10 We write Unit Test for code that has a clear specific purpose, for example, 0:13 we'll often write unit test for the individual functions in a program, 0:18 the unit tests can then call the function without needing to run our entire 0:22 application to make sure we know that the function behaves as we expect. 0:26 Unit Tests are kind of like a basketball drill. 0:31 As a basketball player, you need to master various skills like shooting, 0:34 passing, running, dribbling and so on. 0:38 Basketball players run specific drills to test 0:41 each of these skills outside of an actual game. 0:44 A basketball player might just practice free throws for a while and 0:47 then practice dribbling at a different time without worrying about shooting or 0:51 passing or what their teammates are doing. 0:55 A Unit Test is like one of these drills and 0:58 we can run unit tests constantly during our development process 1:00 to ensure that everything is working every time we make a change. 1:04 But being good at each single thing isn't enough to be 1:08 a really good basketball player. 1:11 They also have to be able to do them all together. 1:13 In addition to practicing each individual basketball skill, 1:16 players practice drills as a team. 1:19 They need to make sure that they can dribble, pass, and 1:21 shoot just as well when there are other people doing their part around them. 1:24 And that they can do them all together in the correct sequence. 1:29 In programming this kind of testing is called Integration Testing. 1:33 You use integration tests when you add new code to preexisting code 1:36 to make sure that not only do all of the pieces work individually as expected, but 1:41 also that they run together correctly without breaking. 1:45 Product managers or people who run open-source projects might also run 1:49 integration tests whenever others write code to contribute to their projects. 1:53 To make sure that the code others write doesn't break their existing project 1:58 that's useful. 2:02 On a basketball team it's not enough that your skills are up to par. 2:03 And that you work well together as a team. 2:07 You also have to play actual games. 2:09 Live games are very different even from practice games, 2:12 we play basketball on different courts. 2:16 With different crowds and against teams with different strategies. 2:18 So being a good basketball team requires a lot of team experience in this context. 2:22 In software, this kind of testing is called End-To-End Testing. 2:29 We fire up the application and 2:33 run it from start to finish for all the user stories we can think of. 2:34 This ensures that the program is ready to go live. 2:38 And that the special details of deployment don't screw up the stuff that we 2:41 carefully tested on our local machines with Unit Test and integration tests. 2:46 We conduct end to end test very occasionally. 2:51 Maybe only a few times during a product's life cycle. 2:53 As a very time consuming and expensive. 2:56 You might conduct some or all of these kind of tests where you work or 2:59 in your personal projects. 3:03 We'll focus on Unit Testing in this course because that's what you'll spend most of 3:04 the time writing. 3:08 Unit Tests actually help us write better code and 3:10 grow as developers as soon as we start using them. 3:13