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I recently published a simple React module that I wrote in TypeScript. I tested my module by importing the local package into a project, and it worked flawlessly. However, now that I've published the module, whenever I try to import it into a project, I get the following error:

Failed to compile.

./src/...
Module not found: Can't resolve '<module>' in '.../src/...'

Package is listed in both package.json and package-lock.json, and the module shows up in node_modules. Additionally, VS Code doesn't throw any fits, so I'm not quite sure what could be the issue.

Isaac Corbrey
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  • I've seen something similar when I forgot to stop the dev server and restart it after installing a package. – Charlie Stanard Jul 15 '20 at 17:08
  • @CharlieStanard I thought about that, but the package still wouldn't resolve after restarting the dev server. I even recloned my project and reinstalled the package and it wouldn't resolve. – Isaac Corbrey Jul 15 '20 at 17:10
  • is the package not built when published? is main field in pkgjson pointing to the right place? is it still linked from when you were doing development? – Dave Ankin Jul 15 '20 at 17:30
  • One thing that could go wrong is that the "main" field in package.json refers to a typescript file instead of the built javascript file that most interpreters could import. – Dave Ankin Jul 15 '20 at 17:31
  • @DaveAnkin It looks like my `"main"` field in `package.json` is indeed pointing at a TypeScript file. Let me change that and republish, I'll let you know how that works out. – Isaac Corbrey Jul 15 '20 at 17:36
  • @DaveAnkin It worked! Please submit that as an answer so I can accept it :D – Isaac Corbrey Jul 15 '20 at 17:45
  • @DaveAnkin If you don't submit an answer within the next day or so I'm just going to add my own and accept that. – Isaac Corbrey Jul 16 '20 at 17:17

1 Answers1

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NPM, being the "Node Package Manager" interprets packages as node modules. in the documentation, it says it will try to load a folder by looking for a package.json file, and resolving the path in main relative to the folder it found.

So when publishing a package with a build step, always make sure to build it before its published (there is a prepublish hook for this, in the scripts object in package.json).

The other thing is to make sure that the package being published refers to the correct main, bin (if applicable), and module (if applicable) paths in the package.json file. if the source file is src/mylib.coffee and the built file is dist/mylib.js, the package.json must contain { "main": "dist/mylib.js" } in order that someone installing this module as a dependency into their node_modules folder would require the correct file.

in short make sure "main" in package.json points to the right file!

Dave Ankin
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