Problem with yarn 2 & 3 and inlined externals

[em]

A little context - npm still hoists all packages to the root package's node_modules directory. Yarn used to do the same. This has always been a deduplication optimization, and never reflected the way node.js's module system actually worked. node.js just resolves dependencies with trial and error, walking up the filesystem and looking for node_modules directories.

It was always a quirk of these hoisting strategies that packages always got hoisted even when a dependency only existed as deep subdependency.

Say you have two rescript packages, let's call them A and B. Package B depends on package A.

package A:

Car.res
@module("car")
external drive = "drive"

package B:

A.Car.drive()

This generates the following:

in package A: car.bs.js:

// Generated by ReScript, PLEASE EDIT WITH CARE
/* This output is empty. Its source's type definitions, externals and/or unused code got optimized away. */

in package B:

import * as Car from "car"
Car.drive()

The import path "car" generated here, is based on the assumption that hoisting has taken place. Which is not guaranteed. Instead I would argue that when a separate rescript module is referenced in this way, the expected output should be:

import * as Car from "A/node_modules/car"

The current behavior does not work with Yarn 2/3 unless the "car" is independently added as a dependency of package B. But then you have to manually ensure the versions always match so the binding in package A are correct in package B.

Another solution is to write all bindings like so:

Car.res
@module("car")
external drive_ext = "drive"
let drive = drive_ext

This bypasses the optimization and resolutions get corrected.

[bobzhang]

Note the work around could be done in a slightly more elegant way:

@module("car")
external drive = "drive"
let drive = drive

[TheSpyder]

The current behavior does not work with Yarn 2/3 unless the "car" is independently added as a dependency of package B.

I have just always assumed transitive ReScript dependencies must be added as explicit dependencies (in both package.json and bsconfig.json). ReScript compiles projects in a flat style, it's not well suited to mapping nested dependency structures.

[stale[bot]]

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