1
00:00:01,290 --> 00:00:05,380
In this video we're going to install a couple of dependencies to get our test setup up and running.

2
00:00:05,480 --> 00:00:07,090
It's going to go over to my terminal.

3
00:00:07,160 --> 00:00:12,720
I'm gonna make sure I'm inside my art service directory and we will do an npm install a very critically

4
00:00:12,750 --> 00:00:17,240
these test dependencies are going to install are going to be marked as development dependencies.

5
00:00:17,340 --> 00:00:20,030
So we're going to add on that save Dev flag right there.

6
00:00:20,100 --> 00:00:24,300
I'll show you why we're adding this in in just a moment and then going to list out all the stuff we're

7
00:00:24,300 --> 00:00:25,330
going to install.

8
00:00:25,410 --> 00:00:34,970
So I'll do an app types just at types super test we'll get just we are going to get something else called

9
00:00:35,000 --> 00:00:45,330
T S just super test and then Mongo DV memory server OK.

10
00:00:45,460 --> 00:00:49,390
So let's run this command because it is going to take a little bit to install and we'll discuss exactly

11
00:00:49,390 --> 00:00:51,900
what's going on with all this.

12
00:00:51,910 --> 00:00:52,200
All right.

13
00:00:52,210 --> 00:00:55,480
So this is going to kick off the installation process and I'm going to sit here at the screen for a

14
00:00:55,480 --> 00:00:56,530
little bit.

15
00:00:56,650 --> 00:01:01,080
You're going to start to see that as we install a very particular package the one called Mongo to be

16
00:01:01,090 --> 00:01:02,050
memory server.

17
00:01:02,050 --> 00:01:05,260
There's actually a rather large download to go along with it.

18
00:01:05,290 --> 00:01:10,000
Now just before this video I pre installed that thing just to save a little bit of time this video but

19
00:01:10,000 --> 00:01:15,580
for you you're probably gonna see that it's downloading a file that is 80 megabytes large or so.

20
00:01:15,640 --> 00:01:19,130
So that is this copy of Mongo TB that is going to be running in memory.

21
00:01:19,150 --> 00:01:24,520
The reason we are running a copy of Mongo in memory is that we can easily test multiple databases at

22
00:01:24,520 --> 00:01:25,470
the same time.

23
00:01:25,630 --> 00:01:30,070
Remember we really want to be able to run tests for different services concurrently on the same machine

24
00:01:30,730 --> 00:01:34,420
that might eventually start to be a little bit challenging if we are having them all connect to the

25
00:01:34,420 --> 00:01:36,150
same instance of Mongo DB.

26
00:01:36,820 --> 00:01:42,550
So rather than having all these different services connecting to the same test instance of Mongo we're

27
00:01:42,550 --> 00:01:49,330
going to instead create a mongo DV memory server or an instance of Mongo in memory for each these different

28
00:01:49,330 --> 00:01:56,450
services we are testing it's going to end up running much much more quickly now that 80 megabyte download

29
00:01:56,510 --> 00:02:00,950
is something that we really do not want to repeat every single time that we tried to build up our Docker

30
00:02:00,950 --> 00:02:03,500
image where the OTT service.

31
00:02:03,500 --> 00:02:07,970
The only thing that's going to be running inside of our docker container or the OSS service is the actual

32
00:02:07,970 --> 00:02:09,330
express application.

33
00:02:09,380 --> 00:02:13,780
We have said that we're not going to be running our tests inside of that image at any point in time.

34
00:02:14,060 --> 00:02:17,900
So we don't really need to install any of these dependencies as we are building that image.

35
00:02:17,900 --> 00:02:21,680
That's why we installed them as D development dependencies.

36
00:02:21,680 --> 00:02:25,790
We're not going to go over to our Docker file and we're going to update it to make sure that whenever

37
00:02:25,790 --> 00:02:30,350
we build an image for the service we do not attempt to install these development dependencies.

38
00:02:30,350 --> 00:02:35,180
And again it's so we can avoid downloading that 80 megabyte file every single time we have to rebuild

39
00:02:35,210 --> 00:02:36,510
our image.

40
00:02:36,620 --> 00:02:38,360
So I got to go back over to my editor.

41
00:02:38,390 --> 00:02:44,840
I'm going to find my Docker file inside the off directory and I'm going to modify the NPM install command.

42
00:02:44,990 --> 00:02:51,770
I'm going to change the very end of it to only broad like so and then I'll save the file.

43
00:02:51,770 --> 00:02:56,820
To now if we ever decide to install more dependencies into our project or change any other file that's

44
00:02:56,820 --> 00:02:59,230
going to cause the image to be rebuilt.

45
00:02:59,250 --> 00:03:02,950
We will not have to sit around and wait for that 80 megabyte download.

46
00:03:03,000 --> 00:03:06,780
This might sound like a very small optimization but you're going to see that we're going to actually

47
00:03:06,780 --> 00:03:12,270
have to rebuild our image several times in the coming videos or as we build in one last thing to our

48
00:03:12,720 --> 00:03:13,620
service here.

49
00:03:13,680 --> 00:03:18,480
And if we had to re download that Mongo DB memory server every single time it would be really annoying

50
00:03:18,540 --> 00:03:19,600
really quickly.

51
00:03:20,270 --> 00:03:20,620
OK.

52
00:03:20,640 --> 00:03:24,530
So back in my terminal it looks like all those dependencies were installed.

53
00:03:24,540 --> 00:03:25,680
Let's take a quick pause right here.

54
00:03:25,680 --> 00:03:27,580
We're going to start to make use of these things.

55
00:03:27,580 --> 00:03:30,420
I know we haven't really discussed each of them in detail yet.

56
00:03:30,420 --> 00:03:32,550
We're going to start to wear them all up in the next video.