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Managing dozens of packages in a project could quickly get out of hand. We know that node modules can contain many files, and uploading all these files can be an unnecessary use of computing resources and time. When we share our apps with others, we need a way for them to install the packages used in the project without transferring all of those files every time. We also need to make sure that our packages are up to date.
Terminal Commands
npm Command Line Usage
- Get help for a command
npm <command> -h- e.g.
npm init -h
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Managing dozens of packages in a project
could quickly get out of hand.
0:00
We know node modules can contain many
files and uploading all of these files can
0:04
be an unnecessary use of
computing resources and time.
0:09
When we share apps with others, we need
a way for them to install the packages
0:12
used in the project without transferring
all of those files every time.
0:17
We also need to make sure that
our packages are up to date.
0:23
npm provides files that allow us to both
track and manage packages in a project.
0:28
It also provides us with a way of avoiding
uploading the node modules folder,
0:33
and any other files or folders we select.
0:38
In the last video, we used npm init
to create a file named package.json.
0:41
We added the dash y flag, and
0:48
this allows us to create the page
with default information.
0:49
If we wanted to customize this on our own,
we do use npm init by itself.
0:54
Let's delete the files and
folders we have now and try this.
1:00
Delete node modules,
package-lock.json, and package.json.
1:11
Now back in the terminal, type npm init.
1:20
This command prompts npm to ask us
a list of questions about the project.
1:26
This is where we set the name.
1:31
We'll go with kayakapp.
1:35
Version number and other information we
might want to share if this project were
1:37
released to the public.
1:41
We'll give it a short description.
1:44
The entry point is the file that
should be run to start the project.
1:51
We can also specify any
tests we'd want to run.
1:56
And the git repository
the project will be stored in,
1:59
as well as any relevant keywords,
the author, and license.
2:04
MIT is a common license for
open source projects.
2:10
So we'll go with that.
2:13
Licenses help others understand how
they can use the code in your project.
2:15
We'll go ahead and hit OK.
2:20
Here's our new customized
package.json file.
2:26
The package.json file will contain other
important information about the project,
2:30
including a list of all
the packages you've installed.
2:34
Let's install express again.
2:42
Now inside of our package.json file,
express is listed as a dependency.
2:50
A dependency is a package that
a project requires to run.
2:56
When others download your project and
run npm install,
3:00
it will install all of the dependencies
listed in package.json.
3:03
However, package.json doesn't always
get updated when packages are updated.
3:07
To track the exact version
of the packages you install,
3:12
NPM uses the package.lock.json file.
3:16
It's similar to package.json,
but contains more information,
3:18
including the exact version
number of installed packages.
3:22
Here we find the exact version
of Express installed is 4.15.1.
3:27
Our package.json only
specifies a range which can be
3:34
any package above this
version in the major range,
3:38
which can be any version above
this in the same major range.
3:42
Remember semantic versioning from earlier.
3:48
This is a place where it's useful
to remember semver and its rules.
3:51
It's possible to update packages
using the npm update command.
3:56
Let's try this out and
check for changes after.
4:02
When we type in npm update express,
if the updated version is within the range
4:05
specified by package.json,
package.json won't change.
4:11
But package-lock.json will
update to the version installed.
4:16
And the range is unchanged
in package.JSON.
4:22
But express has been updated
to the latest version.
4:30
4.17.1 at package-lock.json.
4:35
When a project is downloaded by others and
4:40
they try installing using npm install,
npm install will look for
4:43
a package-lock.json as a source of
truth to find the exact version number.
4:47
This ensures that the application is as
close as possible to the version that you
4:52
have created.
4:57
Now that we have a way to track our
dependencies, let's figure out how to make
4:59
sure our node modules folder doesn't
get included in our GitHub repo.
5:03
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