feat: Resolver control by environment variable "LLRT_PLATFORM"

[nabetti1720]

Issue # (if available)

#680 (comment)

Description of changes

This PR adds the ability to toggle platform preferences in the Node.js package resolver.

// index19.js
import chalk from 'chalk';
console.log(chalk.blue('Hello world!'));

Use "browser":

% export LLRT_PLATFORM=browser
% llrt index19.js
Hello world!

Use "node":

% export LLRT_PLATFORM=node
% llrt index19.js
ReferenceError: Error resolving module 'node:tty' from '/Users/shinya/Workspaces/llrt-test/node_modules/chalk/./source/vendor/supports-color/index.js'

NOTE: This behavior is currently as expected, as the tty module has not yet been merged into mainline.

Non use:

% unset LLRT_PLATFORM
% llrt index19.js
Hello world!

Checklist

• Created unit tests in tests/unit and/or in Rust for my feature if needed
• Ran make fix to format JS and apply Clippy auto fixes
• Made sure my code didn't add any additional warnings: make check
• Added relevant type info in types/ directory
• Updated documentation if needed (API.md/README.md/Other)

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[richarddavison]

Good idea! Just a minor suggestion

[nabetti1720]

@richarddavison , We have also fixed the issue where Windows paths were not being processed correctly, so please check it out.

[richarddavison]

We can avoid a few unwraps. I wonder if we should do this on all paths on after calling require_resolve instead of on a per function basis. Also make that function private to make sure it always return an abs path.

[nabetti1720]

We can avoid a few unwraps. I wonder if we should do this on all paths on after calling require_resolve instead of on a per function basis. Also make that function private to make sure it always return an abs path.

Thinking about it, in this use case, we only need to worry about the package.json resolution process, and since that function can return a Result type, we can avoid using unwrap().