A Comprehensive Guide to Working with Unpublished Node.js Dependencies

As a full-stack Node.js developer, you‘ve likely encountered situations where you need to use an unpublished module as a dependency in your project. Maybe it‘s an unfinished feature in a teammate‘s module, or you need to conduct integration testing before the dependency code is ready for prime time on npm.

Working with unpublished dependencies can be tricky. You can‘t just npm install them as you would a public module. And manually copying over the source code gets old fast, especially if the dependency is under active development.

Fortunately, there are several techniques for elegantly working with unpublished Node modules. In this in-depth guide, we‘ll explore four key approaches:

1. Using npm link for local development
2. Installing directly from a Git repository
3. Publishing and installing from a private npm registry
4. Bundling dependencies with npm pack

We‘ll cover the ins and outs of each method, including detailed instructions, pros and cons, and best practices. By the end, you‘ll be equipped to handle any unpublished dependency situation like a pro!

Symlinking Dependencies with npm link

The npm link command is one of the quickest ways to start using an unpublished module in your project. It works by creating symlinks between your project‘s node_modules folder and the global npm module directory on your machine.

Here‘s how the process works under the hood:

1. When you run npm link in a module directory, npm creates a symlink from the global modules directory ({prefix}/lib/node_modules/) to your local module directory.

2. When you then run npm link [module-name] in your project directory, npm creates a symlink from your local node_modules folder to the global symlink created in step 1.

3. Node.js and npm treat the symlinked module as if it was installed normally in your local node_modules folder.

Here‘s a visual representation:

+-- global npm modules 
|   `-- [module-name] -> /path/to/local/module
|
+-- your-project
    `-- node_modules
        `-- [module-name] -> global sym link

The beauty of this setup is that any changes you make to the local module code are immediately reflected in your project. There‘s no need to constantly reinstall or copy files over.

However, symlinking does have a few gotchas:

• Global pollution: If you npm link the same module in multiple projects, they‘ll all be pointing at the same code. Changes in one project could unintentionally break others.

• Versioning issues: Since linked modules bypass the normal npm versioning system, it‘s easy to get out of sync with the expected module version in your package.json file.

• Limited to local development: Symlinks only work on your local file system. You‘ll still need to eventually publish the module or bundle it with your app for production use.

npm link is great for quick local testing and development, but it‘s not a long-term solution for sharing unpublished code. Use it sparingly and with caution!

Installing from a Git Repository

Did you know that you can install npm packages directly from a Git repository? This is super handy for testing out features or fixes in a branch or pull request before they‘re officially published.

To install from a Git repo, just include the repository URL in your project‘s package.json file:

{
  "dependencies": {
    "some-module": "git+ssh://[email protected]:user/some-module.git#branch-name"
  }
}

A few key things to note about the URL format:

• It must start with git+ssh:// or git+https://
• You can use shorthand like github:user/repo, gitlab:user/repo, etc.
• Specify the branch name after a # symbol
• You can also target specific commits or tags using their SHA or tag name

After adding the Git URL to your dependencies, a quick npm install will clone down the repo and symlink the specified code into your node_modules folder.

One big advantage of this approach over npm link is that the installed module is local to your project. You don‘t have to worry about global symlink pollution. It also makes it easier to test against multiple branches or versions of a dependency simultaneously.

However, there are some significant security implications to consider. When you install a Git dependency, you‘re essentially giving that code full access to your machine. A malicious module could wreak havoc! Always be extremely cautious about installing from untrusted Git repositories.

Git installs are great for quick, one-off testing of features or bug fixes. But for regular use of unpublished dependencies, you‘ll want to consider a more robust solution like a private npm registry.

Hosting a Private npm Registry

For larger teams and organizations, setting up a private npm registry is often the best way to manage sharing unpublished Node modules. A private registry acts as a gatekeeper between your internal code and the outside world. You get all the benefits of using npm, but with added security and control over what gets published.

There are several great options for hosting your own npm registry:

• Verdaccio is a lightweight open-source registry with a focus on simplicity and ease of use. It can be installed as a global npm module and run on any Node.js server.

• npm Enterprise is npm‘s official private registry solution. It‘s a fully-managed SaaS product with advanced features like single sign-on and detailed access controls. Pricing starts at $7/user/month.

• JFrog Artifactory is a universal artifact repository that can host npm packages alongside many other formats. It‘s a powerful enterprise solution with advanced features like high availability and geo-replication.

The basic process for setting up a private npm registry looks like this:

1. Install and configure your registry software on a server that‘s accessible to your team
2. Set up user accounts and authentication (often via SSO or username/password)
3. Configure npm on your development machines to point to the private registry
4. Publish your internal modules to the private registry
5. Install the private modules in your projects as usual with npm install

Let‘s walk through a simple example of setting up a Verdaccio registry on a local machine.

First, install Verdaccio globally:

npm install -g verdaccio

Next, run the verdaccio command to start the server:

verdaccio

By default, Verdaccio will start a registry server at http://localhost:4873. You can configure the host, port, and other settings in a config.yaml file.

To create a user account, run:

npm adduser --registry http://localhost:4873  

You‘ll be prompted for a username, password, and email address.

Now, to publish a module to your Verdaccio registry, just run npm publish as usual from within the module directory. You‘ll need to be logged in as a user with appropriate permissions.

Finally, to install modules from the Verdaccio registry, update your project‘s .npmrc file to include:

registry=http://localhost:4873

Or pass the --registry flag to npm on the command line:

npm install some-module --registry http://localhost:4873

And that‘s the basics of running a private npm registry with Verdaccio! It‘s a powerful solution that brings the full npm experience to your internal development workflow.

Of course, there‘s a lot more you can do to enhance your registry, like setting up single sign-on, publishing via CI/CD pipelines, and configuring access controls. But even a basic private registry can be a huge improvement over ad-hoc methods like npm link and Git installs.

Bundling Dependencies with npm pack

One final technique to consider for working with unpublished dependencies is using the npm pack command. This command bundles up a module and all its dependencies into a single tarball file (.tgz). You can then share that tarball with other developers or projects.

To create a package tarball, navigate to the module directory and run:

npm pack

npm will generate a .tgz file named [module-name]-[version].tgz in the current directory.

To install the bundled module in another project, copy the tarball file to the project directory and run:

npm install [module-name]-[version].tgz

The module and its dependencies will be installed in the node_modules folder, just as if you had installed from the public npm registry.

Bundling has a few advantages over other methods of sharing unpublished code:

• Self-contained: The tarball includes all of the module‘s dependencies, so you don‘t have to worry about version conflicts or missing sub-dependencies.

• Versioned: The tarball filename includes the module version, making it easy to track and manage different releases.

• Easily shareable: Tarballs are just single files, so they‘re easy to email, upload, or otherwise share with others.

However, tarballs can also quickly become outdated if the bundled module is under active development. As a best practice, make sure to communicate clearly with your team about which tarballs to use and when to regenerate them. You may also want to consider using a simple versioning scheme for your tarballs (e.g. some-module-1.2.3-alpha.1.tgz).

Conclusion and Recommendations

In this guide, we‘ve explored four powerful techniques for working with unpublished Node.js dependencies:

1. npm link: Great for quick local development and testing, but beware of global symlink pollution and versioning issues.

2. Git installs: An easy way to test branches and pull requests before merging and publishing. Just be extremely cautious about security when installing from untrusted repos.

3. Private npm registries: The most robust and full-featured solution for organizations. Provides all the benefits of the public npm registry with added security and access control.

4. Tarballs (npm pack): A simple way to bundle and share modules and their dependencies. Useful for infrequent sharing or when a private registry is overkill.

So which technique should you use? As with most development decisions, it depends on your specific needs and constraints. Here are some general guidelines:

• For quick local development and testing, npm link is a good place to start. Just be sure to clean up your global symlinks when you‘re done to avoid pollution.

• If you need to test a specific branch or pull request, installing from a Git URL is the way to go. But only do this with repos and collaborators you trust.

• For medium to large organizations that frequently share internal code, a private npm registry is often the best solution. It provides the most control, security, and reliability.

• If you only need to occasionally share a module or are working with a small team, creating and distributing tarballs with npm pack may be sufficient.

The most important thing is to be deliberate about your approach. Establish clear conventions and communicate them to your team. A little bit of process and tooling goes a long way towards avoiding dependency hell!

Additional Resources:

• npm link documentation
• Installing from a Git URL
• Verdaccio private npm registry
• npm pack documentation

I hope this guide has been helpful in navigating the world of unpublished Node dependencies. If you have any other tips or techniques to share, please let me know in the comments!