Feature request: Support --cpu and --os flag to specify platform specific install

[archfz]

Use case

Given the os and cpu package.json attributes, and the rise on usage of optionalDependencies for native modules, and also given cross platform building of certain applications like electron, it would be nice to be able to install npm packages for a given platform, disregarding current platform.

My case is having a thrid party native module using optionalDependencies to install platform specific node bindings. Now this module is bundled together with an electron app, and the build pipeline uses wine to build it for windows as well from debian. The issue is that the thrid party native module will always be installed with linux native bindings.

Proposal

The proposal is to have two extra possible arguments for npm install. --os would specify for what operating system to install packages, --cpu for what cpu. The defaults for these options would be from current platform.

Example: npm i --os win32 --cpu x64

[ljharb]

feature requests go in https://github.com/npm/rfcs

[alex-kinokon]

RFC Link: npm/rfcs#612