NuGet package: nuget.org/packages/RendleLabs.UnpkgCli

dotnet unpkg

I got fed up of needing to have Node.js and NPM installed just so I could install front-end packages like jQuery and Bootstrap. I'm not using Webpack or anything, and I don't want 100MB of node_modules in every project.

So I made a dotnet command to do it instead.

Why should I use it?

Because you're building an ASP.NET Core application which just needs common front-end packages like Bootstrap, jQuery and Popper.js, and it's going to serve them from a CDN in Production but with fallback to local files. You're not compiling your front-end code with Webpack or anything, and you just want an easy way to acquire those libraries, without needing to install Node.js and NPM or Yarn or Bower, and without adding a Gulp or Grunt step just to copy the files you actually need out of node_modules.

unpkg is written in C#, with no dependency on JavaScript runtimes, so it installs as a .NET Global Tool. It'll grab the files you need from the same public CDN you can use for Production — unpkg.com — and puts them right into wwwroot\lib, where they belong.

Why shouldn't I use it?

If you are building a complex SPA, with Angular or TypeScript or Webpack or suchlike, and you've got code that loads packages from node_modules using import syntax, then this is not for those projects, and you should use NPM. (You could also use Yarn, but that's by Facebook so for all you know it might be sending copies of your dependency graphs to shady data-mining organisations; be careful out there.)

How does it work?

There's a magic CDN called unpkg.com that delivers files from NPM packages. If those packages follow a simple rule, which is to put all their runtime files into a folder called dist, they can be served from unpkg.

It also provides metadata about the packages in JSON format, including the integrity hash that you can use in your script tags to make sure you're getting the right data and the user's connection hasn't been compromised.

unpkg uses that metadata to discover the files in the package and download them right into your wwwroot/lib folder.

Sometimes the packages don't have a dist folder, in which case unpkg will download pretty much everything.

Usage

You'll need the .NET Core SDK 2.1 installed on your machine.

Then you can install the package as a global tool like this:

$ dotnet tool install -g --version 2.0.0 RendleLabs.UnpkgCli

Then, from the command line:

$ unpkg add vue

It supports NPM-namespaced packages:

$ unpkg add @aspnet/signalr

You can install multiple packages in a single command:

$ unpkg add jquery bootstrap popper.js

If you want a specific version, use the @ notation:

$ unpkg add bootstrap@3.3.7

You can also specify a path within the package, which is a feature I added specifically for Bootswatch so I could do this:

$ unpkg add bootswatch/yeti

That just installs the Yeti theme within the larger Bootswatch package. If you just install Bootswatch by itself, you'll get all 20-odd themes.

You can also specify paths with namespaced packages. This is incredibly useful if you want to install Rx.js because it's huge, and all you want is the global folder:

$ unpkg add @reactivex/rxjs/global

And you'll just get the four <script>-tag-friendly files that you need, and not the hundreds of Node and Webpack and source files.

Add specific versions using @ notation, e.g.

$ unpkg add jquery@3.3.0

Update to latest versions of packages with a single command:

$ unpkg update

To update specific packages just add their names, e.g.

$ unpkg update bootstrap

Aliases for commands:

• add is also a
• restore is also r
• update is also u, up or upgrade because I can never remember which one it is

If you want to restore files as part of your build, you can install the RendleLabs.Unpkg.Build NuGet package. Alternatively, after installing the CLI tool, you can unpkg --add-task to achieve the same result.

Override where unpkg puts your files instead of wwwroot by one of:

• JSON config file in $HOME/.unpkg/unpkg.config
• Environment variable UNPKG_WWWROOT
• JSON config file in ./unpkg.config
• --wwwroot=public

It's using .NET Core Configuration, so each of those will override the previous ones.

unpkg.json

The add command stores the details about the files it downloaded into a file in the current directory, unpkg.json. Once that's there, you can just run

$ unpkg restore

to redownload everything, and it remembers the version, too, so it won't sneakily upgrade you to jQuery 4.0 when you're not looking.

If you can get all your wwwroot/lib dependencies using unpkg, then you can add it to your .gitignore and save checking all those files in. Just make sure the unpkg.json file is checked in.

Once you've got a package installed, the restore command will just use the info from unpkg.json, so if there are files you don't want you can edit it and remove them. Saving should be non-destructive. If you run add again for a package that is already in unpkg.json, it will be overwritten with whatever version it finds on the CDN.

Integrity hashes

The other thing that goes into the unpkg.json file is the integrity hash for each file. You should use this in your <script> and <link> tags, like this:

Example script tag

<script src="https://unpkg.com/jquery@3.3.1/dist/jquery.slim.js"
  asp-fallback-src="~/lib/jquery/jquery.slim.min.js"
  asp-fallback-test="window.jQuery"
  crossorigin="anonymous"
  integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo">
</script>

Example link tag

<link href="https://unpkg.com/bootswatch@4.0.0/dist/darkly/bootstrap.min.css"
  rel="stylesheet"
  integrity="sha384-p8bH4RlA/kdF4wbAoep+/6VeOQI2IAWa9zLjTIQbQLv2FuCjX/W/FkdYdeKISDvK"
  crossorigin="anonymous"
  asp-fallback-href="~/bootstrap4/bootstrap/bootswatch.min.css"
  asp-fallback-test-class="sr-only"
  asp-fallback-test-property="position"
  asp-fallback-test-value="absolute" />

Note to self: maybe generate these tags, either as an extra command or into another file somewhere?

Open Source

unpkg is open source, and incorporates the work of other open source projects, specifically:

• UNPKG by Michael Jackson
• semver by Max Hauser
• JSON.NET by James Newton-King

Thank you to all these creators for their contributions to the open-source ecosystem.