Experiments with node.js interoperability using the latest Dart 3 features.

1. Run webdev build --output bin:build/gen to generate the js. Files should be generated in the build/gen directory.
2. Modify the import in build/main_with_preamble.js with the name of the new entrypoint generated in step 1.
3. Run node build/main_with_preamble.js to test the compiled js.

• Alternatively, you can also run it in the browser by using webdev serve build:8080.

NOTE: For some reason, webdev serve isnt regenerating the js files on change, so this implementation currently requires use of webdev build first.

• webdev build --output bin:build/gen
• webdev serve build:8080

• basic node.js interop script using 0 dependencies
• create a JS interop type that represents the (built-in) console log
• verify platform agnostic type (e.g. console) can be run from browser.
• create a Node.JS interop type that only exists via an import (e.g. fs)
• create a Browser JS interop type, and verify it doesn't work using node

• can the node.js preamble be programatically added to existing build_web_compilers? (see: https://github.com/dart-lang/build/tree/82889aea57247a32b327f4e51e5c42f4b70fb230/build_web_compilers#manual-usage)
• can we get intellisense to work on generated code (possibly using jsconfig.json)? this would help debug issues at compile time, rather than run time
• build Dart extension type definitions from ts declaration files
• couldn't access import.meta.url (didn't try everything) - is there a reason that this would be needed in node.js

Some use cases to validate full functionality with.

• VSCode extension interop
• ReactJS interop

Dart currently doesn't have a way to declare modules that can automatically be imported into the global scope. There are two options (but possibly more) for dealing with module imports:

• only use static imports (e.g. <script> in index.html)
• explicitly import a module using js_interop.importModule('fs')

note: unsure why static imports cant be used, e.g:

import { foo } from "foo";

Relevant:

• dart-lang/sdk#53783
• dart-lang/sdk#52852
• deferred loading of a library - https://dart.dev/language/libraries#lazily-loading-a-library

The generated dart code requires some preamble in order to interop with node.js (e.g. adding require to the global scope for future import statements).

An issue has been opened against buid_web_compilers to allow custom premable scripts to be added to the compiler output.

Note: digging around build_modules may give some insight on how to customize the build pipeline.

Dart hot reload cannot work together to hot reload NodeJS. Unlocking this feature would likely require interop with a JS reloader, e.g. Webpack HMR.

TODO: description

see:

• https://pub.dev/packages/chartjs - old js interop example
• https://github.com/dart-archive/js_facade_gen - used to generate chart.js interop example