wasm to js packaging

Usage

# install all dependencies in the mono-repo
pnpm install
# setup git hooks
npx simple-git-hooks

# install rust, cargo etc
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
rustup update
cargo install -f wasm-bindgen-cli wasm-opt

Notes

• Bundlers need to support ESM Integration Spec normally with a plugin.
• The wasm-bindgen bundler target relies on the ESM Integration Spec and this spec requires top-level await support that only works in an ESM context.
• Bundlers normally should use the bundler target even for SSR because they need to have an import statement to figure out where the wasm file is.
  • The nodejs target just uses fs calls to read the wasm file and that make it harder for bundlers to figure out where the wasm file is.
• For an isomorphic package you are forced to use ESM everywhere (ie. wasm-esm)
• We can't use main for the nodejs target in package.json because Next JS uses that instead of export maps for SSR.

Remix

Remix does not support ESM Integration Spec yet, the server side loads the nodejs target and run properly but the client side fails to load the wasm file. It needs the esbuild wasm plugin to work here.

The server side runs properly in this repo but will probably fail on a real deploy because it does not copy the wasm file to the build folder.

Frameworks support

• Svelte Kit
• Next
• Remix
• Astro
• Solid ???

License

MIT © Hugo Dias