ShadowRealm Integration

What is the problem this feature will solve?

ShadowRealm is a TC39 stage 3 proposal that introduces a new built-in to provide a distinct global environment, with its own global object containing its own intrinsics and built-ins. Its ability is similar to Node.js built-in vm.Context, however, ShadowRealm provides a stronger guarantee on object exchanges across realm boundaries.

As the ShadowRealm is a distinct global environment, Web integration is also under work (Like 1) to define which web APIs should be exposed in the ShadowRealm so that people can still utilize the Web APIs that still useful in the ShadowRealm. The line generally draw between the APIs that should be exposed in the ShadowRealm or not is generally if the APIs are side-effect-free to the host environment.

What is the feature you are proposing to solve the problem?

ShadowRealm is currently under active development in v8. The design doc of the Host API could be found at here. I'd believe in Node.js we may need to be able to re-evaluate the native modules in the ShadowRealm so that their object graph is not tangled with the main context, to not violate the principle of the design. /cc @nodejs/startup

I'd believe there are a bunch of modules that are useful and can stand in the line of side-effect-free, like EventEmitter, Stream, URL, etc. Also, the Web APIs that are available in Node.js like WebStream could also follow the Web specs to be exposed in the ShadowRealm. We may need to list all the possibilities that can be available in the ShadowRealm, and eventually make them available in the ShadowRealm.

Design Doc: https://docs.google.com/document/d/12_CkX6KbM9kt_lj1pdEgLB8-HQaozkJb7_nwQnHfTTg/edit?usp=sharing

/cc @nodejs/vm

Start by reading the ShadowRealm proposal, the linked V8 issue, and the Node.js Host API and design documents. The issue does not name source files, tests, or a specific entry point. Done would require an agreed scope for ShadowRealm integration and implementation of the selected native modules and Web APIs.