Sharing resource definition between a JS host and Rust guest

[fabricedesre]

I'm trying to build a system where the JS host can implement delegates and pass them to the Rust side - think about abstracting cryptographic operations to use the WebCrypto API in a browser for instance.

Unfortunately it looks like the 2 JS files generated don't play well together in that case. I put up a runnable demo at https://github.com/fabricedesre/wit-test

Is that a codegen limitation, or something more fundamental?

[esoterra]

I'm not sure exactly what you're trying to do, but I can hopefully point you in the right direction.

Here are some relevant resources related to what you're trying to do

• WASI Crypto - A standardized API for cryptographic primitives
• Related questions Rust-import/Wasmtime-export: Examples of using multiple modules together #292, Importing and exporting from the same module with shared types #293, which we expect are solved by the next bullet
• Profiles (*.world) - A new file that allows you to define the various imports and exports of a module/component together in one place (see component-model draft PR and open issue here)

[fabricedesre]

Thanks, I'll take a look - indeed #293 and profiles seems to cover the same problem space.

If that matters, my target environment is browsers, so WASI & wasmtime are less directly relevant to me.

[alexcrichton]

I think that this is a duplicate of #266 (importing/exporting things at the same time) so I'm going to close this in favor of that.