WEBVTT 00:00.970 --> 00:01.803 -: In the last section, 00:01.803 --> 00:03.930 we were able to start up our test suite separately 00:03.930 --> 00:06.330 using Docker Compose. 00:06.330 --> 00:08.190 This new container definitely respects 00:08.190 --> 00:09.300 the volumes that we set up. 00:09.300 --> 00:12.390 So any time that we change our project files or folders, 00:12.390 --> 00:14.970 the test suite is going to see the change to those files 00:14.970 --> 00:16.290 and automatically rerun, 00:16.290 --> 00:17.880 which is definitely ideal. 00:17.880 --> 00:19.290 However, you'll notice that we've still got 00:19.290 --> 00:21.120 this kind of interactive menu right here. 00:21.120 --> 00:24.210 It would be really great to be able to press P, T, or Q 00:24.210 --> 00:26.460 to filter by file name, test name, 00:26.460 --> 00:27.870 or essentially just work around 00:27.870 --> 00:29.850 with the test suite a little bit. 00:29.850 --> 00:32.130 But we can see that if we hit Enter here, 00:32.130 --> 00:37.130 or P or Q or T, W, whatever it might be, 00:37.590 --> 00:40.020 none of this input that we're adding into our terminal 00:40.020 --> 00:42.930 is getting sent over to the running test suite. 00:42.930 --> 00:45.030 So quick reminder on why that's occurring. 00:47.010 --> 00:48.960 Here's a diagram of what's happening right now. 00:48.960 --> 00:52.110 We've got our test container and the web container. 00:52.110 --> 00:53.730 Both of those different containers 00:53.730 --> 00:56.190 start up with a primary command. 00:56.190 --> 00:59.100 For the test container, it's npm run test. 00:59.100 --> 01:01.950 And for the web container, it's npm run start. 01:01.950 --> 01:04.620 Anytime a process is created inside these containers, 01:04.620 --> 01:06.090 it automatically gets a connection 01:06.090 --> 01:09.330 to stdin, stdout, and stderr. 01:09.330 --> 01:10.320 And as a reminder, 01:10.320 --> 01:14.430 stdout, stdin, and stderr are all process-specific. 01:14.430 --> 01:16.650 So every different process inside this container 01:16.650 --> 01:20.010 has its own instance of stdin and stdout. 01:20.010 --> 01:22.440 Now, we are currently typing in our terminal, 01:22.440 --> 01:25.710 but there's nothing in place that is taking our text input, 01:25.710 --> 01:27.270 like the keys we are pressing, 01:27.270 --> 01:29.640 and automatically forwarding that input 01:29.640 --> 01:32.280 over to stdin of the test container. 01:32.280 --> 01:33.360 That would be ideal, 01:33.360 --> 01:35.550 but it's not set up to do that by default. 01:35.550 --> 01:37.440 And unfortunately, using Docker Compose, 01:37.440 --> 01:39.900 we cannot easily set that up. 01:39.900 --> 01:42.810 So let's try taking a slightly alternate approach here. 01:42.810 --> 01:45.810 Let's try creating a second terminal window, 01:45.810 --> 01:47.190 and in that terminal window, 01:47.190 --> 01:50.700 we're going to run the docker attach command. 01:50.700 --> 01:52.560 Remember what docker attach does. 01:52.560 --> 01:53.640 With docker attach, 01:53.640 --> 01:55.800 we can forward input from our terminal 01:55.800 --> 01:58.680 directly to a specific container. 01:58.680 --> 02:00.300 Let's try that out and see if we can't 02:00.300 --> 02:02.790 kind of get that connection to the test suite 02:02.790 --> 02:04.590 and be able to hit P, Q, T, 02:04.590 --> 02:08.070 all those different things to manipulate the test suite. 02:08.070 --> 02:10.770 All right, so I'm gonna open up a second terminal window, 02:10.770 --> 02:11.603 and inside of here, 02:11.603 --> 02:14.190 I'm gonna get the ID of that running container 02:14.190 --> 02:15.900 with docker ps. 02:15.900 --> 02:17.670 So here's the ID of the container. 02:17.670 --> 02:20.073 Make sure you've got the one for npm run start. 02:21.360 --> 02:24.000 I'll then try running docker attach, 02:24.000 --> 02:25.950 and then I'll put that ID in. 02:25.950 --> 02:29.190 So again, remember what docker attach does. 02:29.190 --> 02:32.224 We are attaching to the stdin, stdout, 02:32.224 --> 02:35.730 and stderr of the primary process inside that container. 02:35.730 --> 02:38.490 So in theory, if we type something into our terminal, 02:38.490 --> 02:42.510 that input will be sent to stdin on that primary process. 02:42.510 --> 02:44.610 So let's see what happens. 02:44.610 --> 02:45.990 I'll run that command. 02:45.990 --> 02:47.220 And then it looks like my cursor 02:47.220 --> 02:48.390 is just kind of hovering here, 02:48.390 --> 02:50.760 so it feels like something is going correctly. 02:50.760 --> 02:55.760 I'll try putting in P, Q, T, W, anything, 02:55.860 --> 02:56.693 and it looks like, 02:56.693 --> 02:59.520 well, it's not quite working as we expect. 02:59.520 --> 03:01.590 Okay, so let me cut to the chase here. 03:01.590 --> 03:04.110 Unfortunately, this is as good as it gets 03:04.110 --> 03:07.170 with the Docker Compose solution for running our tests. 03:07.170 --> 03:08.580 When we use Docker Compose, 03:08.580 --> 03:12.090 we're not going to be able to manipulate our test suite 03:12.090 --> 03:16.080 by entering P, T, Q, any of these special commands. 03:16.080 --> 03:17.130 With Docker Compose, 03:17.130 --> 03:18.930 this output right here is essentially 03:18.930 --> 03:21.480 as good as it's going to get. 03:21.480 --> 03:23.460 But I still wanna show you why that is. 03:23.460 --> 03:25.230 So I wanna give you a little bit of a background here 03:25.230 --> 03:26.520 and kind of apply some of the knowledge 03:26.520 --> 03:28.260 we picked up earlier in the course about Docker 03:28.260 --> 03:30.930 to understand why we are not going to be able to attach 03:30.930 --> 03:33.570 directly to that container and enter in commands 03:33.570 --> 03:36.930 and have them be affecting that running test process. 03:36.930 --> 03:39.483 Okay, so kind of a deep-dive here, but let's do it. 03:40.530 --> 03:43.230 So clearly, when we enter in additional text here, 03:43.230 --> 03:46.170 it is not at all manipulating the test suite. 03:46.170 --> 03:49.170 I wanna open up a second, or now, a third terminal window. 03:49.170 --> 03:50.040 And inside of here, 03:50.040 --> 03:52.050 we're gonna start up a shell instance 03:52.050 --> 03:53.580 inside that running container, 03:53.580 --> 03:54.480 and we're going to explore 03:54.480 --> 03:56.520 some of the different running processes. 03:56.520 --> 03:58.950 So I'm going to again do docker ps. 03:58.950 --> 04:01.560 I'm going to get the ID of that container. 04:01.560 --> 04:02.700 And I'll do, this time, 04:02.700 --> 04:07.440 docker exec -it, the id, and then sh. 04:07.440 --> 04:08.910 So remember what this does. 04:08.910 --> 04:10.860 This is going to run a new command 04:10.860 --> 04:12.560 inside the container with this ID. 04:13.440 --> 04:14.730 With -it right here, 04:14.730 --> 04:17.340 we are starting up a connection to stdin 04:17.340 --> 04:19.770 on this new command that we are going to run. 04:19.770 --> 04:21.810 And then sh over here on the very end 04:21.810 --> 04:24.360 is gonna start up essentially a new shell 04:24.360 --> 04:27.120 or kind of a command prompt inside the terminal. 04:27.120 --> 04:30.750 Shell is very similar to Bash or Z shell, if you use that. 04:30.750 --> 04:32.070 It's essentially just allowing us 04:32.070 --> 04:35.400 to enter some commands directly into the container. 04:35.400 --> 04:36.330 So I'm gonna run that. 04:36.330 --> 04:38.340 You see that we get our command prompt right here. 04:38.340 --> 04:40.440 And then we're going to run ps, 04:40.440 --> 04:42.810 which is going to print out all the running processes 04:42.810 --> 04:44.960 that we have going on inside the container. 04:46.050 --> 04:48.000 So this is the reason why docker attach 04:48.000 --> 04:50.550 did not quite work the way we expected. 04:50.550 --> 04:52.950 Notice how we have a PID right here of 1 04:52.950 --> 04:54.543 for the command npm. 04:55.530 --> 04:57.840 We've then got a separate process running 04:57.840 --> 05:00.450 for react-scripts start 05:00.450 --> 05:04.320 and yet another PID for some other script's start thing 05:04.320 --> 05:05.490 right here. 05:05.490 --> 05:08.220 All right, so why is the text that we're entering 05:08.220 --> 05:11.340 into the attached window over here not showing up? 05:11.340 --> 05:13.410 Well, that all comes down to the different processes 05:13.410 --> 05:15.810 that have been created inside the container. 05:15.810 --> 05:17.940 You see, when we run npm run test, 05:17.940 --> 05:20.880 we're not actually running directly npm run test. 05:20.880 --> 05:24.540 In reality, what is running is the process npm. 05:24.540 --> 05:27.630 And then npm looks at the additional arguments 05:27.630 --> 05:30.330 we are providing, specifically run test, 05:30.330 --> 05:33.660 and it uses those additional arguments to decide what to do. 05:33.660 --> 05:37.530 So npm is going to eventually start up a second process 05:37.530 --> 05:39.390 that is actually running our tests, 05:39.390 --> 05:41.190 and that is one of these two right here. 05:41.190 --> 05:43.050 I'll be honest, I don't actually know which one it is. 05:43.050 --> 05:45.120 It's essentially just one of the two. 05:45.120 --> 05:46.290 And so we might imagine that, 05:46.290 --> 05:47.640 hey, let's just say it's this one right here. 05:47.640 --> 05:50.370 That's the process that is running our test suite. 05:50.370 --> 05:51.240 So we can kind of imagine 05:51.240 --> 05:54.510 that there's a second process in here called start.js. 05:54.510 --> 05:55.770 And this is the process 05:55.770 --> 05:57.840 that is actually executing our test suite 05:57.840 --> 06:00.060 and receiving commands over stdin 06:00.060 --> 06:02.190 to understand when to filter down the test suite 06:02.190 --> 06:04.860 or rerun them or whatever it might be. 06:04.860 --> 06:08.010 The problem is that when we run docker attach, 06:08.010 --> 06:10.920 we always attach to stdin 06:10.920 --> 06:13.210 of the primary process of the container 06:14.370 --> 06:16.500 with the process ID of 1. 06:16.500 --> 06:19.530 And so that's always going to be the direct npm command. 06:19.530 --> 06:21.120 But it's not the npm command 06:21.120 --> 06:23.580 that is in charge of receiving those key presses 06:23.580 --> 06:27.630 and interpreting all those kind of different options we have 06:27.630 --> 06:30.870 of the P, T, and Q, and Enter right here. 06:30.870 --> 06:34.560 It's the secondary process that was started by npm. 06:34.560 --> 06:37.590 And so ideally, to be able to interact with that test suite, 06:37.590 --> 06:40.380 we would want to attach to that other command 06:40.380 --> 06:42.330 or that other running process. 06:42.330 --> 06:43.770 But unfortunately, with docker attach, 06:43.770 --> 06:45.810 that is just not an option. 06:45.810 --> 06:47.430 Anytime we run docker attach, 06:47.430 --> 06:50.430 we are always getting a handle on the primary process, 06:50.430 --> 06:52.980 not the secondary one over there. 06:52.980 --> 06:54.090 So, like I said, 06:54.090 --> 06:56.550 unfortunately, as far as the test suite goes, 06:56.550 --> 06:59.160 this is kind of as good as it gets. 06:59.160 --> 07:01.230 We can either execute Docker Compose 07:01.230 --> 07:03.720 to start up our tests inside of a second container. 07:03.720 --> 07:04.800 Now, that's definitely convenient, 07:04.800 --> 07:06.690 because we just have to run Docker Compose 07:06.690 --> 07:08.670 and boom, we get all of our tests running. 07:08.670 --> 07:10.200 But the downside to this approach 07:10.200 --> 07:12.510 is that we do not have the ability 07:12.510 --> 07:14.760 to kind of manipulate the running test suite 07:14.760 --> 07:17.610 with the P, T, and Q shortcuts. 07:17.610 --> 07:18.750 That's one option. 07:18.750 --> 07:19.660 The other option 07:20.700 --> 07:23.370 is to have just the single running container, 07:23.370 --> 07:27.870 so that primary container of web right here, 07:27.870 --> 07:30.120 and then we can run the docker exec command 07:30.120 --> 07:32.250 to start up our test suite inside there. 07:32.250 --> 07:33.180 The benefit to that 07:33.180 --> 07:35.190 is that we can manipulate the test suite, 07:35.190 --> 07:37.530 but as you saw, the downside was that we had to memorize 07:37.530 --> 07:39.330 that docker exec command 07:39.330 --> 07:42.300 and we also had to get the ID of the running container. 07:42.300 --> 07:45.000 So, like I said, at the end of the day, two solutions here. 07:45.000 --> 07:47.490 Neither of them are really 100% ideal, 07:47.490 --> 07:49.530 but at least you can pick one of the two 07:49.530 --> 07:51.390 that you like a little bit more to run your tests 07:51.390 --> 07:52.593 if you decide to do so. 07:53.790 --> 07:55.080 Now, the last thing I wanna mention here 07:55.080 --> 07:57.210 is that there are definitely test suites out there 07:57.210 --> 08:00.150 for other languages or even other JavaScript test suites 08:00.150 --> 08:01.530 besides the one we are using 08:01.530 --> 08:02.760 that do not actually have 08:02.760 --> 08:05.610 this kind of command line interaction, 08:05.610 --> 08:06.930 where you press in these commands 08:06.930 --> 08:09.660 and it manipulates the test suite in some fashion. 08:09.660 --> 08:11.580 There are definitely other test suites out there 08:11.580 --> 08:14.040 that you just run 'em and that's pretty much it. 08:14.040 --> 08:17.130 They just run, and you don't manipulate them in any fashion. 08:17.130 --> 08:18.630 So it's definitely not necessarily 08:18.630 --> 08:19.710 the worst thing in the world 08:19.710 --> 08:21.540 that we can't kind of get a handle on this thing. 08:21.540 --> 08:22.650 It would be nice if we could, 08:22.650 --> 08:24.660 but unfortunately, we just can't. 08:24.660 --> 08:26.520 So that's pretty much it on testing. 08:26.520 --> 08:28.170 So let's take a quick pause right here, 08:28.170 --> 08:30.120 and we'll continue in the next section.