2

I have a package (package-a) that depends on another package (package-b) which is not published to npm but is on my file system. When I run npm install from package-a, package-b's dependencies are not installed. I have to navigate to package-b's directory and run npm install manually. Is there a way to install both packages' dependencies with a single npm command?

Here's my directory structure:

/
  ...
  shared/
    ...
    javascript/
      ...
      package-b/
        package.json
  package-a/
    package.json

Per the docs, I placed the following in package-a/package.json. (I'm using npm 5+)

dependencies: {
  package-b: "file:../shared/javascript/package-b",
}

When I navigate to /package-a and run npm install, it installs all of package-a's dependencies like normal and also copies the package-b directory to package-a/node_modules. This is presumably what lets me type require('package-b') instead of require('../shared/javascript/package-b') .

However, as I stated before, package-bs dependencies are not installed, so if I try to use package-a, I get an error when package-b is required because it is trying to use dependencies that do not exist locally.

Once again, to solve this, I can navigate to package-b and run npm-install, but I'm hoping there's a better solution as I may have many such sub packages and I'd like to avoid having to write a shell script to go install all my dependencies if I can do this with an npm command. (perhaps I just did something wrong and npm install should be working?)

Follow up question: when I run npm install from package-b's directory, the packages are installed there, but not in the version of package-b that got copied to /package-a/node_modules during the first npm install, yet everything still works. So now it seems like when I require('package-b') it is actually resolving to /shared/javascript/package-b and NOT /package-a/node_modules/package-b. So what's the point of copying the file in the first place?

Update

It turns out this is a bug in npm 5. It only occurrs when installing from a package-lock.json file. (Github Issue)

Luke
  • 5,567
  • 4
  • 37
  • 66

1 Answers1

1

The files are (probably) not being copied, they're being symbolically linked (symlink). This essentially creates an alias/shortcut that looks like a real directory, but points to another path.

This is how the older npm link feature worked. The reason is the code stays "live"; Changes in the linked module are reflected whenever you run the module that's referencing them, meaning you don't have to npm update all the time.

Soviut
  • 88,194
  • 49
  • 192
  • 260
  • this answers my second question (thanks), but not my first – Luke Aug 13 '17 at 21:44
  • Turns out the behavior in question is due to a bug in npm. I'll accept this answer now as it answers my second question. – Luke Aug 14 '17 at 13:34