additional CLI JS runtime notes

readme.md

@@ -10,3 +10,7 @@ For use in the Rust Ludus backend.
 * The canonical reference for all this is https://rustwasm.github.io/wasm-bindgen/introduction.html.
 * Look into what thi.ng does with Zig in its WASM packages: https://github.com/thi-ng/umbrella/tree/develop/packages, especially https://github.com/thi-ng/umbrella/tree/develop/packages/wasm-api.
   - It's looking like `--target web` is the most appropriate to use in 2024, since they use ES modules and not CommonJS, which is what everything else uses (and necessitates the build step). See https://rustwasm.github.io/wasm-pack/book/commands/build.html.
+  - Bun can run the `index.js` file just fine.
+  - Deno can, too, but it requires file read access, since that's kind of Deno's thing.
+  - Node cannot. See https://rustwasm.github.io/wasm-pack/book/prerequisites/considerations.html. You have to polyfill `fetch` with `node-fetch` (https://github.com/node-fetch/node-fetch).
+    * Obligatory: stop trying to make fetch happen.

src/lib.rs

@@ -5,6 +5,7 @@ use wasm_bindgen::prelude::*;
 #[wasm_bindgen(module = "/things.js")]
 extern "C" {
     fn foo() -> String;
+    fn print(s: String);
 }
 
 #[wasm_bindgen]
@@ -15,6 +16,8 @@ extern "C" {
 // without the line in Cargo.toml, this throws a lint warning
 #[wasm_bindgen]
 pub fn greet() {
-    let from_js = foo();
-    alert(format!("Hello, {from_js}"));
+    let s = foo();
+    let out = format!("Hi there from Rust. I got {s}");
+    alert(out.clone());
+    print(out);
 }

things.js

@@ -1 +1,5 @@
 export function foo () {return "bar"}
+
+export function print (s) {
+  console.log(s)
+}