npmlink-cp

An extremely lightweight (less than 100 lines of code) but powerful Node.js tool that simulates npm link by copying the files using the same rules of filtering than npm publish and npm install use[1].

It's all done inside the code without any third dependencies[2].

Background (why)

There are situations when your awesome-package becomes unstable using npm link when you tries to use a library of your own that it's not as mature as you'd like, so you need to make one or two fixes on it once a while.

This has happened to me in packages that use module bundlers/uglifiers and libraries that depends on database drivers.

Alternative solutions

There are several workarounds to this issue.

Use npm

Execute npm publish+npm install or npm pack+tar -x everytime you make any alterations on your dependencies.

• Pros: You don't have to install anything additional (perhaps tar).
• Cons: Too slow.

Create your own script

Create a shell script top copy the exact files that npm would create by itself.

• Pros: You don't have to install anything additional.
• Cons: You need to create different scripts for each linked dependency (or a complex script that accepts different file lists or then parsing the package.json, .npmignore, etc.).

Install some third party tools

There are some tools that already do this work for you.

• Pros: You only have to make a npm install -g ...
• Cons:
  • Most of these tools depend on several other packages, populating your global space with potential version problems or at least occuping more space than necessary.
  • Most of them don't follow the rules to include or ignore files that npm use, making a copy of all files (except node_modules).

Installation

$ npm install -g npmlink-cp

Usage

$ npmlink-cp <path to package1> [<path to package2>]...]

Footnotes

[1]: bundledDependencies are not yet supported.

[2]: NodeJs 10+ is required. To test it, we're using mock-fs, jasmine, and istanbul.