Supporting transitive mappings for npm: specifiers

[guybedford]

I was just running some tests to see if I can map transitive dependencies with Deno npm: specifiers along the lines of:

{
  "imports": {
    "react": "npm:[email protected]"
  },
  "scopes": {
    "npm:[email protected]": {
      "loose-envify": "npm:[email protected]"
    }
  }
}

Where there is an import of import 'react' against the above import map in Deno.

Supporting the scoped npm:[email protected] in the above would be great for extending import maps support to npm specifiers without treating the version resolution as a fully opaque process. It would also make it easier to switch from Deno npm packages to eg JSPM versions of packages for moving from a browser to server workflow.

Has this been discussed at all, or are there any particular hurdles to achieving this kind of support, would be really interested to hear opinions!

//cc @dsherret

[luizfilipe]

Thanks @dsherret for guiding me to this open thread, so currently, does it not work with npm packages?

I also tried this, and it does not seem to work.

  "scopes": {
    "npm:[email protected]": {
      "restructure": "npm:[email protected]"
    }
  }

[oscarotero]

@dsherret Just to clarify:

• To use import maps with NPM is required to install them with npm?
• Are there plans to allow to do that in the future without creating a node_modules folder?

[adamgreg]

Am I right in thinking the same issue applies to JSR dependencies? If so, will the byonm workaround work for those until this is addressed?

[dsherret]

1. To use import maps with NPM is required to install them with npm?

npm doesn't support import maps so in order to override deps of deps using byonm in deno, you'd need to specify npm overrides https://docs.npmjs.com/cli/v8/configuring-npm/package-json#overrides ...then run an explicit npm install for it to setup the nodes_modules folder.

2. Are there plans to allow to do that in the future without creating a node_modules folder?

Yeah, this issue would cover that.

Am I right in thinking the same issue applies to JSR dependencies? If so, will the byonm workaround work for those until this is addressed?

No, this issue is unrelated to JSR dependencies unless you're pulling in JSR dependencies via npm. If just using jsr: specifiers then import maps are possible, though a bit of a pain to use atm.