How to support multi-platform binary packages distributed via optionalDependencies?

[alshdavid]

I am authoring an npm package that distributes native binaries. Native binaries are compiled and therefore they are platform specific.

To reduce the download burden on consumers, I have split the binaries into multiple packages, each containing their respective platform binary.

@alshdavid/mach-linux-amd64
@alshdavid/mach-linux-arm64
@alshdavid/mach-macos-amd64
@alshdavid/mach-macos-arm64
@alshdavid/mach-windows-amd64
@alshdavid/mach-windows-arm64

Each package specifies the appropriate bin path for the platform

{
  "name": "@alshdavid/mach-linux-amd64",
  "bin": { "mach": "bin/mach" },
  "os": ["linux"],
  "arch": ["x64"]
}

{
  "name": "@alshdavid/mach-windows-amd64",
  "bin": { "mach": "bin\\mach.exe" },
  "os": ["win32"],
  "arch": ["x64"]
}

I then have an entry-point package that acts as a proxy to download the package that contains the platform specific binary

{
  "name": "@alshdavid/mach",
  "optionalDependencies": {
    "@alshdavid/mach-linux-amd64": "0.0.22",
    "@alshdavid/mach-linux-arm64": "0.0.22",
    "@alshdavid/mach-macos-amd64": "0.0.22",
    "@alshdavid/mach-macos-arm64": "0.0.22",
    "@alshdavid/mach-windows-amd64": "0.0.22",
    "@alshdavid/mach-windows-arm64": "0.0.22"
  }
}

When a user installs the entry package; npm, yarn and pnpm will ignore the packages that don't have a matching os and arch field.

npm install @alshdavid/mach
> installed 2 packages
  - @alshdavid/mach
  - @alshdavid/mach-linux-amd64

Currently, no package manager creates a link to the bin for the optionalDependency, they seem to only create links for direct dependencies.

I would like to tell the package managers to use the bin for their platform.

My current solution

Right now in my entry package (@alshdavid/mach), I have added a thin bin target that acts as a proxy to redirect to the correct target.

{
  "name": "@alshdavid/mach",
  "bin": { "mach": "bin.cmd" },
  "scripts": { "postinstall": "node postinstall.mjs" }
  //...

Initially bin.cmd is an empty file, there to provide something for npm/yarn/pnpm to link against.

Windows uses the file extension to determine how to run the file where *nix systems will use the #!. The extension is ignored for *nix systems allowing me to use the same bin target for all OSes (I have run chmod +x bin.cmd).

My postinstall script will detect the OS and if it's Windows, it will modify the bin.cmd with the following contents:

@echo off
SET TARGET_PATH=
FOR /F %%I IN ('node -e "const { dirname } = require(\"path\"); process.stdout.write(dirname(require.resolve(\"@alshdavid/mach-windows-amd64/package.json\")))"') DO @SET "TARGET_PATH=%%I"
"%TARGET_PATH%\bin\mach.exe" %*

And if it's a *nix OS it will modify the bin.cmd with this:

#!/bin/sh
set -e
BIN_PATH=$(node -e \"const { dirname } = require('node:path'); process.stdout.write(dirname(require.resolve('@alshdavid/mach-linux-amd64/package.json')))\")"
"$BIN_PATH/bin/mach" $@

Limitations

This mostly works, however it doesn't work for pnpm, yarn4 and I am unsure if it will work for global installations.

Is there an idiomatic way that works across the package managers that allows me to target the correct binary from an optionalDependency for my application?

[alshdavid]

I also considered parsing the npm_user_agent environment variable in the process.env during the postinstall script, then running yarn/npm/pnpm install @alshdavid/mach-linux-amd64 however this doesn't work for all package managers either.