1 00:00:01,260 --> 00:00:02,200 ‫In this lecture, 2 00:00:02,200 --> 00:00:03,783 ‫we're going to talk about a bunch of 3 00:00:03,783 --> 00:00:05,980 ‫more stuff that you should know 4 00:00:05,980 --> 00:00:08,630 ‫about working with npm packages, 5 00:00:08,630 --> 00:00:13,610 ‫such as versioning, updating, or deleting packages, 6 00:00:13,610 --> 00:00:17,043 ‫and also some other stuff, so let's get started. 7 00:00:18,860 --> 00:00:20,670 ‫The first thing that I want to talk about 8 00:00:20,670 --> 00:00:25,670 ‫in this video is these version numbers of our packages. 9 00:00:26,000 --> 00:00:28,110 ‫Most of the packages on npm 10 00:00:28,110 --> 00:00:31,510 ‫follow the so-called semantic version notation, 11 00:00:31,510 --> 00:00:34,140 ‫which means that their versions numbers 12 00:00:34,140 --> 00:00:36,913 ‫is always expressed with these three numbers. 13 00:00:38,010 --> 00:00:41,000 ‫The first one here is called the major version. 14 00:00:41,000 --> 00:00:44,190 ‫The second one is called the minor version. 15 00:00:44,190 --> 00:00:47,460 ‫The third one is called the patch version. 16 00:00:47,460 --> 00:00:51,604 ‫There's actually a meaning in these three numbers. 17 00:00:51,604 --> 00:00:55,160 ‫The patch version, which is just this last one here, 18 00:00:55,160 --> 00:00:58,080 ‫is only intended to fix bugs. 19 00:00:58,080 --> 00:01:01,750 ‫Let's say that in version 1.18, 20 00:01:01,750 --> 00:01:04,150 ‫the developers found a bug and so 21 00:01:04,150 --> 00:01:08,663 ‫they fixed that bug and then released 1.18.1. 22 00:01:09,860 --> 00:01:11,320 ‫Then they found another bug 23 00:01:11,320 --> 00:01:14,840 ‫and then they released 1.18.2 24 00:01:14,840 --> 00:01:18,843 ‫and so on and so forth until they reached 1.18.11, 25 00:01:20,350 --> 00:01:22,203 ‫which is the current version number. 26 00:01:23,450 --> 00:01:27,140 ‫Again, this last one here is just for bug fixes. 27 00:01:27,140 --> 00:01:31,040 ‫Then after that, we have the minor version. 28 00:01:31,040 --> 00:01:32,670 ‫The minor version introduces 29 00:01:32,670 --> 00:01:35,130 ‫some new features into the package, 30 00:01:35,130 --> 00:01:38,170 ‫but it does not include breaking changes. 31 00:01:38,170 --> 00:01:41,270 ‫All the changes that are done in a new version number 32 00:01:41,270 --> 00:01:43,593 ‫will always be backward-compatible. 33 00:01:44,751 --> 00:01:47,410 ‫If one day the nodemon team, for example, 34 00:01:47,410 --> 00:01:51,290 ‫decides to release version 1.19, 35 00:01:51,290 --> 00:01:54,110 ‫well, that will then include some new features 36 00:01:54,110 --> 00:01:56,570 ‫but it will not break our code. 37 00:01:56,570 --> 00:01:59,750 ‫And the same of course happens with this one here. 38 00:01:59,750 --> 00:02:03,230 ‫So if some day, there is Slugify 1.4, 39 00:02:03,230 --> 00:02:06,190 ‫well then our code is still going to work the same. 40 00:02:06,190 --> 00:02:08,320 ‫There will not be any breaking changes. 41 00:02:08,320 --> 00:02:10,600 ‫Simply there will be something new, 42 00:02:10,600 --> 00:02:14,947 ‫so some new features, which are not just bug fixes. 43 00:02:14,947 --> 00:02:17,940 ‫Bug fixes again are for the third, 44 00:02:17,940 --> 00:02:19,850 ‫so for the patch version, 45 00:02:19,850 --> 00:02:23,870 ‫and then minor new features are for the minor version. 46 00:02:23,870 --> 00:02:26,620 ‫Then of course, we have the major version, 47 00:02:26,620 --> 00:02:28,840 ‫which is only bumped up whenever it is 48 00:02:28,840 --> 00:02:33,140 ‫a huge new release which can have breaking changes. 49 00:02:33,140 --> 00:02:36,500 ‫For example, if Slugify 2 comes along. 50 00:02:36,500 --> 00:02:39,000 ‫Well our code might no longer work 51 00:02:39,000 --> 00:02:42,130 ‫because the slugify function that we have here 52 00:02:42,130 --> 00:02:44,856 ‫for example, might have changed its name 53 00:02:44,856 --> 00:02:48,940 ‫or maybe the parameter that it expects here are different 54 00:02:48,940 --> 00:02:51,240 ‫or the options might have changed, 55 00:02:51,240 --> 00:02:53,210 ‫or something might have changed 56 00:02:53,210 --> 00:02:55,123 ‫that will break previous version. 57 00:02:57,040 --> 00:02:59,720 ‫Be aware that when there is a new version, 58 00:02:59,720 --> 00:03:02,020 ‫it might usually affect 59 00:03:02,020 --> 00:03:03,570 ‫the code that you already have. 60 00:03:05,030 --> 00:03:07,300 ‫Because of that, it is also important 61 00:03:07,300 --> 00:03:09,823 ‫to talk about updating packages. 62 00:03:10,670 --> 00:03:12,620 ‫In our package.json file, 63 00:03:12,620 --> 00:03:15,258 ‫this small symbol here that comes in front 64 00:03:15,258 --> 00:03:18,460 ‫of the version number is what specifies 65 00:03:18,460 --> 00:03:22,363 ‫which updates we accept for each of the packages. 66 00:03:23,290 --> 00:03:27,430 ‫This symbol here, which npm specifies here by default 67 00:03:27,430 --> 00:03:31,900 ‫means that we accept patch and minor releases. 68 00:03:31,900 --> 00:03:34,890 ‫Now, how do we actually update packages? 69 00:03:34,890 --> 00:03:39,080 ‫Well, let's actually quit this process here. 70 00:03:39,080 --> 00:03:40,580 ‫The first thing that we can do 71 00:03:40,580 --> 00:03:44,120 ‫is to check if there are any outdated packages. 72 00:03:44,120 --> 00:03:49,120 ‫We write npm outdated, and that should then give us 73 00:03:49,720 --> 00:03:51,530 ‫actually a table with all 74 00:03:51,530 --> 00:03:53,125 ‫the packages that are outdated. 75 00:03:53,125 --> 00:03:55,970 ‫Well right now, they're all up-to-date, 76 00:03:55,970 --> 00:03:57,860 ‫so that didn't really happen. 77 00:03:57,860 --> 00:03:59,021 ‫What I want to show you now 78 00:03:59,021 --> 00:04:01,550 ‫is that we can actually install 79 00:04:01,550 --> 00:04:05,240 ‫a certain package with a certain version number. 80 00:04:05,240 --> 00:04:06,945 ‫Let's do that with the Slugify 81 00:04:06,945 --> 00:04:11,003 ‫and install it at version 1.0.0. 82 00:04:13,980 --> 00:04:18,980 ‫Npm install slugify and then at 1.0.0. 83 00:04:22,220 --> 00:04:23,233 ‫Let's try that out. 84 00:04:25,645 --> 00:04:29,560 ‫Now indeed, we have one zero zero. 85 00:04:29,560 --> 00:04:31,740 ‫When we hover it, it actually says 86 00:04:31,740 --> 00:04:35,773 ‫latest version 1.3.4, which is what we had. 87 00:04:36,660 --> 00:04:40,630 ‫But if we now run npm outdated, 88 00:04:40,630 --> 00:04:43,390 ‫it should then give us that. 89 00:04:43,390 --> 00:04:46,360 ‫We see that current is 1.0.0. 90 00:04:46,360 --> 00:04:50,642 ‫Wanted is 1.3.4, because that is the one that we accept 91 00:04:50,642 --> 00:04:53,060 ‫because remember, that with this here, 92 00:04:53,060 --> 00:04:56,820 ‫we accept all the patch and all the minor releases, 93 00:04:56,820 --> 00:04:59,821 ‫but of course, we can also change that. 94 00:04:59,821 --> 00:05:04,580 ‫For example, we can set it to this symbol here. 95 00:05:04,580 --> 00:05:07,860 ‫This will then only accept patch releases. 96 00:05:07,860 --> 00:05:09,483 ‫This one is a bit safer. 97 00:05:10,960 --> 00:05:13,570 ‫If we run npm outdated now again, 98 00:05:13,570 --> 00:05:14,693 ‫let's see what we get. 99 00:05:15,590 --> 00:05:19,150 ‫Now the wanted is only 1.0.2, 100 00:05:19,150 --> 00:05:22,690 ‫because again, we only accept minor versions. 101 00:05:22,690 --> 00:05:26,090 ‫So 1.3.4 is not accepted by us 102 00:05:26,090 --> 00:05:28,670 ‫because well, we do not accept 103 00:05:28,670 --> 00:05:30,820 ‫any of the minor releases, 104 00:05:30,820 --> 00:05:33,670 ‫so again, just patch releases. 105 00:05:33,670 --> 00:05:38,670 ‫If you were to do npm update slugify now, 106 00:05:41,460 --> 00:05:42,903 ‫let's see what we got then. 107 00:05:45,360 --> 00:05:48,440 ‫Now we're at 1.0.2. 108 00:05:48,440 --> 00:05:49,537 ‫You see that it changed back 109 00:05:49,537 --> 00:05:52,930 ‫for my updating configuration here 110 00:05:52,930 --> 00:05:56,360 ‫to accept minor and patch releases. 111 00:05:56,360 --> 00:05:58,763 ‫Not just the patch releases like we had before. 112 00:06:01,010 --> 00:06:02,820 ‫If we're going to run this now again, 113 00:06:02,820 --> 00:06:04,180 ‫it should actually bump us up 114 00:06:04,180 --> 00:06:08,163 ‫all the way to 1.3.4, like we had before. 115 00:06:09,710 --> 00:06:11,343 ‫Indeed, here we go. 116 00:06:12,550 --> 00:06:16,060 ‫All right, that is how we update packages. 117 00:06:16,060 --> 00:06:18,240 ‫There are other configurations 118 00:06:18,240 --> 00:06:20,040 ‫that we can choose here. 119 00:06:20,040 --> 00:06:23,070 ‫We can say, for example, that we want 120 00:06:23,070 --> 00:06:25,970 ‫all of the versions, so if at some point, 121 00:06:25,970 --> 00:06:28,790 ‫there is a version two and if we didn't update 122 00:06:28,790 --> 00:06:30,930 ‫our packages, it will then automatically 123 00:06:30,930 --> 00:06:33,633 ‫bump our version up to version two. 124 00:06:34,590 --> 00:06:36,903 ‫This one includes all the versions, 125 00:06:38,259 --> 00:06:40,880 ‫even ones with breaking changes. 126 00:06:40,880 --> 00:06:43,530 ‫But that's not a good idea usually, 127 00:06:43,530 --> 00:06:46,330 ‫and so I usually just go with this one 128 00:06:46,330 --> 00:06:49,510 ‫that is default, or sometimes even this one here 129 00:06:49,510 --> 00:06:52,740 ‫because at some point, even if a minor release 130 00:06:52,740 --> 00:06:54,880 ‫should simply introduce new features 131 00:06:54,880 --> 00:06:57,690 ‫but no breaking changes, we know that sometimes 132 00:06:57,690 --> 00:07:00,490 ‫there can be bugs that developers do not found, 133 00:07:00,490 --> 00:07:02,270 ‫and then these bugs, they find their way 134 00:07:02,270 --> 00:07:05,010 ‫into our code and might break our code. 135 00:07:05,010 --> 00:07:07,600 ‫We do not want that, of course. 136 00:07:07,600 --> 00:07:09,700 ‫The safest version is to just 137 00:07:09,700 --> 00:07:12,149 ‫use this one for bug fixes. 138 00:07:12,149 --> 00:07:15,510 ‫Let's actually just keep it like this here, 139 00:07:15,510 --> 00:07:17,783 ‫just for demonstration purposes. 140 00:07:19,183 --> 00:07:20,950 ‫This is what you need to know about 141 00:07:20,950 --> 00:07:23,123 ‫version numbers and updating. 142 00:07:24,030 --> 00:07:26,443 ‫But we can of course also delete packages. 143 00:07:27,350 --> 00:07:30,493 ‫Let's now go ahead and install Express, 144 00:07:36,280 --> 00:07:40,140 ‫so that we can then go ahead and delete it after that. 145 00:07:40,140 --> 00:07:43,000 ‫I'm sure that you can guess how we can do that. 146 00:07:43,000 --> 00:07:44,960 ‫That is very easy. 147 00:07:44,960 --> 00:07:49,620 ‫Npm uninstall, so it's actually not called delete. 148 00:07:49,620 --> 00:07:51,510 ‫It's really uninstalling. 149 00:07:51,510 --> 00:07:56,303 ‫We install and we uninstall Express. 150 00:07:58,170 --> 00:08:00,460 ‫That will then delete it from 151 00:08:00,460 --> 00:08:02,941 ‫our node modules folder, and also from 152 00:08:02,941 --> 00:08:05,960 ‫our dependencies in a package.json file. 153 00:08:06,920 --> 00:08:11,000 ‫Each time we decide not to use a module anymore, 154 00:08:11,000 --> 00:08:14,140 ‫well, we should always go ahead and remove it, 155 00:08:14,140 --> 00:08:15,983 ‫or actually uninstall it. 156 00:08:16,900 --> 00:08:19,450 ‫Now as a final thing, I want to talk a little bit 157 00:08:19,450 --> 00:08:22,240 ‫about the node modules folder. 158 00:08:22,240 --> 00:08:24,010 ‫This folder, which contains all 159 00:08:24,010 --> 00:08:26,600 ‫the dependencies of our project. 160 00:08:26,600 --> 00:08:29,210 ‫Let's say that you want to share your code 161 00:08:29,210 --> 00:08:31,393 ‫with someone, or that you, for example, 162 00:08:31,393 --> 00:08:33,550 ‫want to start working on one computer 163 00:08:33,550 --> 00:08:35,850 ‫and then move to the next one. 164 00:08:35,850 --> 00:08:39,140 ‫You will never share this node modules folder 165 00:08:39,140 --> 00:08:42,330 ‫because this code, you can easily get it from npm. 166 00:08:42,330 --> 00:08:44,570 ‫There's no need to go ahead and copy 167 00:08:44,570 --> 00:08:46,760 ‫all of this code here, for example, 168 00:08:46,760 --> 00:08:50,730 ‫to a GitHub repository or to a Dropbox folder, 169 00:08:50,730 --> 00:08:54,040 ‫or really somewhere that you want to share your code, 170 00:08:54,040 --> 00:08:56,000 ‫because this folder here as you see 171 00:08:56,000 --> 00:08:58,616 ‫has tons of folders and each of them 172 00:08:58,616 --> 00:09:01,670 ‫might have tons of files. 173 00:09:01,670 --> 00:09:03,670 ‫All of a sudden, you might end up with 174 00:09:03,670 --> 00:09:06,313 ‫tens or hundreds of thousands of files. 175 00:09:07,718 --> 00:09:09,860 ‫You should never share this folder 176 00:09:09,860 --> 00:09:13,173 ‫and never check it out into your GitHub repository. 177 00:09:14,680 --> 00:09:17,620 ‫Let's say that you uploaded this code 178 00:09:17,620 --> 00:09:21,173 ‫to your GitHub account without this node modules, 179 00:09:22,580 --> 00:09:25,020 ‫or you put it into a Dropbox on one computer 180 00:09:25,020 --> 00:09:27,660 ‫and downloaded it at the other one. 181 00:09:27,660 --> 00:09:30,464 ‫Let's say we now downloaded this code here, 182 00:09:30,464 --> 00:09:32,780 ‫so without node modules. 183 00:09:32,780 --> 00:09:34,540 ‫So we delete that one now 184 00:09:36,050 --> 00:09:38,523 ‫and end up with just a regular project folder. 185 00:09:39,720 --> 00:09:42,092 ‫How do we now get back our dependencies 186 00:09:42,092 --> 00:09:44,180 ‫or our node modules folder? 187 00:09:44,180 --> 00:09:46,120 ‫Well, it's very easy. 188 00:09:46,120 --> 00:09:48,503 ‫All we have to do is npm install. 189 00:09:55,490 --> 00:09:58,950 ‫What it did is to read our package.json file, 190 00:09:58,950 --> 00:10:02,030 ‫read our dependencies, and then download everything 191 00:10:02,030 --> 00:10:05,860 ‫back into this folder, all right. 192 00:10:05,860 --> 00:10:07,940 ‫Now one important piece of this puzzle 193 00:10:07,940 --> 00:10:10,503 ‫is the package-lock.json file. 194 00:10:12,290 --> 00:10:15,070 ‫If we open that up, we get a list of 195 00:10:15,070 --> 00:10:17,710 ‫all the versions of all the packages 196 00:10:17,710 --> 00:10:19,210 ‫that we're actually using. 197 00:10:19,210 --> 00:10:22,093 ‫That includes the dependencies of our dependencies. 198 00:10:23,100 --> 00:10:25,373 ‫Let's go to Slugify, for example. 199 00:10:28,030 --> 00:10:29,910 ‫Slugify, and so here we see that 200 00:10:29,910 --> 00:10:31,413 ‫we're using version 1.3.4. 201 00:10:33,270 --> 00:10:35,600 ‫That is very important because 202 00:10:35,600 --> 00:10:38,420 ‫if you share your code, you want the other developer 203 00:10:38,420 --> 00:10:40,190 ‫or even yourself to be using 204 00:10:40,190 --> 00:10:42,450 ‫the exact same package versions, 205 00:10:42,450 --> 00:10:45,760 ‫so that your code works the exact same way for you 206 00:10:45,760 --> 00:10:47,300 ‫and for the other developer. 207 00:10:47,300 --> 00:10:50,200 ‫For that, the exact version numbers 208 00:10:50,200 --> 00:10:52,380 ‫are basically set in stone 209 00:10:52,380 --> 00:10:54,833 ‫in this package-lock.json file. 210 00:10:56,624 --> 00:10:58,850 ‫If you share your code, no matter if you're using 211 00:10:58,850 --> 00:11:02,180 ‫GitHub or Dropbox or something like that, 212 00:11:02,180 --> 00:11:04,690 ‫always share your package.json file 213 00:11:04,690 --> 00:11:07,660 ‫and the package-lock.json file 214 00:11:07,660 --> 00:11:09,690 ‫because these two files are necessary 215 00:11:09,690 --> 00:11:12,460 ‫for the other developer to then reconstruct 216 00:11:12,460 --> 00:11:15,143 ‫basically the node modules folder. 217 00:11:18,232 --> 00:11:20,860 ‫Yeah, I think that's all you need to know 218 00:11:20,860 --> 00:11:23,600 ‫about package versions, updating, 219 00:11:23,600 --> 00:11:28,230 ‫uninstalling, and also sharing code with npm, 220 00:11:28,230 --> 00:11:31,710 ‫package.json and package-lock.json. 221 00:11:31,710 --> 00:11:33,870 ‫If there's anything more that you want to know, 222 00:11:33,870 --> 00:11:37,320 ‫you can again always ask in the course Q and A 223 00:11:37,320 --> 00:11:39,323 ‫and then you'll get help there.