Ability to use a local copy of npm package

[brc-dd]

Is there any way to use a local (modified) copy of an NPM package instead of a published one in this command? Thanks!

deno run -A --unstable npm:vite

[dsherret]

No, it's not something that's possible at the moment, but definitely on our radar. It wouldn't be difficult to implement. It's more a question of how it's specified so if anyone has any ideas let us know.

Maybe like npm:///path/to/local/package/folder, then if you do npm:///path/to/local/package/folder/some/sub_path.js it would resolve the first actual package.json going up the parents (so at /path/to/local/package/folder/package.json) and then resolve the rest of the path (./some/sub_path.js) as a subpath from there. I'm not sure though and there's probably some way that breaks down.

[brc-dd]

For now, I suppose just some way to use tarball would be sufficient, one can just do npm pack and deno run. 🤔

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 7 days if no further activity occurs. Thank you for your contributions.

[yisibl]

Yes, we need the ability to import local packages.

Usage scenario: I am an author of an npm package and I need to test if my npm package works well in deno.

[JonasBa]

+1 here, I am attempting to make test an npm package using native modules in deno and this would have made my life much easier

[JonasBa]

@dsherret mind providing some extra context around this? I might try and find some time to give this a go

[dsherret]

This one probably requires about 1-2 weeks of work because we'd have to support having multiple paths for what we consider to be "node code" and it introduces a new concept in npm resolution where we need to get package information from the file system instead of just the npm registry and then also make this work with node resolution. I wouldn't recommend it as a first task.

In the meantime, for testing npm packages locally you can use the --node-modules-dir flag to cache an existing version of a package locally and make modifications to it. For example:

> cat main.ts
import CodeBlockWriter from "npm:code-block-writer@12.0.0";
console.log(CodeBlockWriter);
> deno cache --node-modules-dir main.ts
> # overwrite the contents of node_modules/.deno/code-block-writer@12.0.0/node_modules/code-block-writer here and make sure to leave the `.initialized` file
> deno run --node-modules-dir main.ts # this will now use your modifications

[brc-dd]

Something like verdaccio should also work along with NPM_CONFIG_REGISTRY env var 👀

[jedwards1211]

This would solve the problems with CI testing that npm packages work with Deno: #19621

[alexgleason]

In the meantime, for testing npm packages locally you can use the --node-modules-dir flag to cache an existing version of a package locally and make modifications to it. For example:

I could not get this to work at all until I added a package.json file containing an empty object {} in the same directory. Then it worked.