How do I package a node module for BuckleScript / ReasonML? - npm

Question

Background
I'm an absolute beginner in BuckleScript, and while I've downloaded packgages with npm before, I've never written a library.
Goal: installing my new package local package in my project using npm
I am trying to wrap some parts of the service worker api in JavaScript. I have started with a file bs-service-worker/src/ExtendableEvent.re like so
type _extendableEvent('a);
type extendableEvent_like('a) = Dom.event_like(_extendableEvent('a));
type extendableEvent = extendableEvent_like(Dom._baseClass);
[#bs.send] external waitUntil: (extendableEvent, Js.Promise.t('a)) => unit
= "waitUntil";
This compiles and produces ExtendableEvent.bs.js as expected.
Now, though, I'd like to go ahead and test what I have so far by creating a new npm project and importing what I have locally. I created a new sibling directory and did an npm install ../bs-service-worker. That succeeded, and then I did a sanity-check build on my new BuckleScript project. That also succeeded.
The issue: opening my module causes an error
When I add open ExtendableEvent; to Demo.re in the new project, I get the following error:
We've found a bug for you!
/home/el/workbench/bucklescript/bs-service-worker-examples/src/Demo.re 11:6-20
9 │
10 │ /**/
11 │ open ExtendableEvent;
12 │
13 │ /*
The module or file ExtendableEvent can't be found.
- If it's a third-party dependency:
- Did you list it in bsconfig.json?
- Did you run `bsb` instead of `bsb -make-world`
(latter builds third-parties)?
- Did you include the file's directory in bsconfig.json?
What I've tried
I'm guessing I'm misusing BuckleScript here instead of npm because npm is so widely adopted and well documented that I think I'd have found the problem, but I'm definitely not ruling out the possibility that I'm misusing npm, too.
I do have "bs-service-worker" listed as a bs-dependency. I also tried "../bs-service-worker" in case BuckleScript didn't like the virtual directory, but it didn't seem to help.
My npm run build command is indeed npx bsb -make-world.
More code:
bs-service-worker/bs-config.json
{
"name": "bs-service-worker",
"version": "0.1.0",
"sources": {
"dir" : "src",
"subdirs" : true,
"public": "all"
},
"package-specs": {
"module": "commonjs",
"in-source": true
},
"suffix": ".bs.js",
"bs-dependencies": [
],
"warnings": {
"error" : "+101"
},
"namespace": true,
"refmt": 3
}
bs-service-worker-examples/bsconfig.json
{
"name": "bs-service-worker-examples",
"version": "0.1.0",
"sources": {
"dir" : "src",
"subdirs" : true
},
"package-specs": {
"module": "commonjs",
"in-source": true
},
"suffix": ".bs.js",
"bs-dependencies": [
"bs-service-worker",
"bs-fetch",
],
"warnings": {
"error" : "+101"
},
"namespace": true,
"refmt": 3
}
bs-service-worker-examples/package.json
{
"name": "bs-service-worker-examples",
"version": "0.0.1",
"scripts": {
"build": "npx bsb -make-world",
"start": "npx bsb -make-world -w",
"clean": "npx bsb -clean-world"
},
"keywords": [
"BuckleScript"
],
"author": "Eleanor (https://webbureaucrat.bitbucket.io)",
"license": "MIT",
"devDependencies": {
"bs-platform": "^7.3.2"
},
"dependencies": {
"bs-fetch": "^0.6.1",
"bs-service-worker": "file:../bs-service-worker"
}
}
Easy Reproduction of the Issue
The fastest way to reproduce this would be to fork this repository and try to add it as a local npm dependency.

Answer 1

The problem seems to be that you have "namespace": true in your library's bsconfig.json, which will wrap all the modules in a namespace module with a silly generated name based on the name field. In this case it will be BsServiceWorker I think.
You could just remove that setting, or set it to false, but namespacing is a good idea to avoid collisions between modules from different libraries, or your own app, so I would recommend setting it to a custom, sensible name. For example:
"namespace": "ServiceWorker"
You can then open ExtendableEvent in the consumer project with:
open ServiceWorker.ExtendableEvent;
For more details, see the documentation on the namespace field.