WASM instructions (for future reference)

1. Create new rust-wasm project

   cargo new <NAME> --lib

2. add the following to Cargo.toml (or respective versions of the libs):

   # ...
   
   [lib]
   crate-type = ["cdylib"]
   
   [dependencies]
   wasm-bindgen = "0.2"
   
   # helpful (but not necessary) dependencies
   js-sys = "0.3.65" # JS interface
   reqwasm = "0.2" # requests: paired with futures
   wasm-bindgen-futures = "0.4.38" # futures / async / await
   web-sys = { version = "0.3", features = ['console'] } # console logging
   
   [dev-dependencies]
   wasm-bindgen-test = "0.2"

3. build

   cargo build

4. build wasm

   wasm-pack build --release --target web --no-typescript --out-dir <OUT_DIR>

5. In your .js file, this is how to initialize and use:

   import init, { <RUST_WASM_FUNCTIONS_AND_STRUCTS> } from './pkg/<PROJECT>.js';
   // this path is relative to the .js file                 ^^^^^^^^^^^^^^^^^^^
   
   async function init() {
       await init('./pkg/<PROJECT>_bg.wasm');
   }
   
   function example() {
       // if <RUST_WASM_FUNCTIONS_AND_STRUCTS> contains a normal element
       // let's say, a function called `rust_print` and it expects a &str
       rust_print("Hello!");
   }
   
   async function async_example() {
       // if <RUST_WASM_FUNCTIONS_AND_STRUCTS> contains an async element (with futures)
       // let's say, a function called `rust_request`
       await rust_request();
   }
   
   init();
   example();
   await async_example();