How to create mixed JS-Rust projects with NAPI-RS?

[chriskilding]

At the moment, creating an all-Rust module with NAPI-RS is the main use case. But in some cases we need to have some of our module's code in Javascript, and some in Rust.

The reasons for this might include:

• Keeping certain operations within JS to avoid the performance hit of copying to/from Rust
• The need to call Node API functions

Does NAPI-RS support mixed JS-Rust projects today, and if so how?

[TheBrenny]

So I think I'm running into a similar problem... Instead of exposing all my rust functions, I want to write a wrapper over the top, but for some parts, invoked the bindings directly. The way I'm planning on solving this is writing a wrapper that requires the bindings, and then re-exports them as required.

More or less, that's how you'll end up solving your problem: require the bindings, and re-export them, plus a few more - with your main being that "newer" script.

You can specify where you want to save your bindings by specifying the --js "path/to/script.js build argument:

> napi build --js "js_src/bindings.js --platform"
> cd js_src
> ls
bindings.js
bindings.d.js
index.js
index.d.js

Where index.js is your script.