Is there a way in my package.json to tell JSPM not to install a specific dependency?

[onlywei]

For example, can I do something like this in my package.json?

{
  "name": "my-package",
  "dependencies": {
    "a": "^0.1.0",
    "b": "^2.3.5"
  },
  "jspm": {
    "dependencies": {
      "b": null
    }
  }
}

Such that when I do jspm install npm:my-package, I also want JSPM to install "a", but not "b"?

[aluanhaddad]

Hi @onlywei

Yes indeed, using "@empty"

{
  "name": "my-package",
  "dependencies": {
    "a": "^0.1.0",
    "b": "^2.3.5"
  },
  "map": {
    "b": "@empty"
  }
}

A working example from the registry

[josephschmitt]

@aluanhaddad any idea if this is jspm 0.17.x only? We're on 0.16.47 and it's not working.

[onlywei]

@aluanhaddad the working example you have provided and the written example you gave are inconsistent. One is using "map" an the other is using "dependencies". Which one is correct?

[aluanhaddad]

@onlywei I figured that out trying to answer @josephschmitt's question.

Total fail on my part.

"map": {
  "dep": "@empty"
}

works correctly and in both 0.17 and master.

[josephschmitt]

@aluanhaddad ok sorry, just to confirm, in the package with the dependency, I add this "map" key in the root of the package.json? Not inside "jspm"? So it would be:

{
  "name": "my-package",
  "dependencies": {
    "my-unwanted-dep": "1.0.0"
  },
  "map": {
    "my-unwanted-dep": "@empty"
  }
}

[aluanhaddad]

Yes, just like you have it there. Note I tested with the master branch, not with 0.16.47.
It feels like a bug that it doesn't work in the nested "jspm" section.

Sorry for the confusion.

I'm going to leave this issue open to track that bug.

[josephschmitt]

@aluanhaddad ok. Doesn't seem to work with 0.16.47 at all, either in the root or nested in "jspm". Hopefully we can figure out why at some point. Thanks

[aluanhaddad]

looking into it now

[onlywei]

@aluanhaddad I'm also experiencing that it does not work in the root nor nested in "jspm". Maybe I can try upgrading.

[onlywei]

I just upgraded to 0.16.53 and I am not seeing a difference. Using "@empty" does not seem to have any effect at all.

[aluanhaddad]

@onlywei, @josephschmitt sorry for not replying sooner.

I have created a package, to demonstrate that this works. You can find it at https://github.com/aluanhaddad/jspm-registry-1070

The package has two dependencies, jsdom, and jquery.

I have used "map" to specify that JSPM users should not install the dependency on jsdom.

To test, run

$ jspm install github:aluanhaddad/jspm-registry-1070

Observe that jsdom is not installed, but jquery is.

Then run

$ npm install aluanhaddad/jspm-registry-1070

Observe that jsdom and jquery are both installed.

Let me know if this helps

[josephschmitt]

@aluanhaddad thanks, we were finally able to get this working for the most part, closing out this issue.

However, I do want to bring attention to a new issue I'm going to create soon related to this. It seems that if we use this technique of setting @empty, but do so on a dependency which we're not installing in our target app but instead use the sytemjs config's "paths" option, then it'll actually re-write the dependency as import * from '@empty', which then throws errors.

Not sure if this project is the right place to file this issue, but I'll work on creating a stand-alone reproducible example in the mean time I can link you to.

Thanks again for your help.

[josephschmitt]

@aluanhaddad here's the new issue I've filed #1072
Additionally, I've set up this repo as a way to easily reproduce the bug we're seeing https://github.com/josephschmitt/jspm-empty-demo

Let me know if someone is able to help out.

[guybedford]

Yup this is definitely a bug. I'm not sure what the best fix would be though.

Note that jspm 0.17 fixed up a lot of these sorts of mapping cases, it may be worth trying that version if you can.