Setup for TypeScript type gen for WASM using Tsify

- Includes breaking changes to the WASM API surface, since it now accepts objects instead of stringified JSON.

tsify-async/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "tsify-async"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[lib]
+proc-macro = true
+
+[dependencies]
+syn = "1.0"
+quote = "1.0"
+serde-wasm-bindgen = "0.5.0"

tsify-async/src/lib.rs

@@ -0,0 +1,30 @@
+// Copied from https://github.com/madonoharu/tsify/issues/24#issuecomment-1670228789
+// TODO: I think this had more to do with:
+// the trait `From<veilid_core::VeilidUpdate>` is not implemented for `wasm_bindgen::JsValue`
+// than it does with tsify itself... Maybe rename to something else?
+
+use proc_macro::TokenStream;
+use quote::quote;
+use syn;
+
+#[proc_macro_derive(TsifyAsync)]
+pub fn tsify_async_macro_derive(input: TokenStream) -> TokenStream {
+    // Construct a representation of Rust code as a syntax tree
+    // that we can manipulate
+    let ast = syn::parse(input).unwrap();
+
+    // Build the trait implementation
+    impl_tsify_async_macro(&ast)
+}
+
+fn impl_tsify_async_macro(ast: &syn::DeriveInput) -> TokenStream {
+    let name = &ast.ident;
+    let gen = quote! {
+        impl From<#name> for JsValue {
+            fn from(value: #name) -> Self {
+                serde_wasm_bindgen::to_value(&value).unwrap()
+            }
+        }
+    };
+    gen.into()
+}