Try out an export macro

crates/neon-macros/src/lib.rs

@@ -52,3 +52,38 @@ pub fn main(
     )
     .into()
 }
+
+#[proc_macro_attribute]
+/// Export a function
+pub fn export(
+    _attr: proc_macro::TokenStream,
+    item: proc_macro::TokenStream,
+) -> proc_macro::TokenStream {
+    let input = syn::parse_macro_input!(item as syn_mid::ItemFn);
+
+    let attrs = &input.attrs;
+    let vis = &input.vis;
+    let sig = &input.sig;
+    let block = &input.block;
+    let name = &sig.ident;
+    let exported_name = quote::format_ident!("__EXPORTED__{name}");
+
+    quote::quote!(
+        #(#attrs)*
+        #vis #sig {
+            #[neon::macro_internal::linkme::distributed_slice(neon::macro_internal::EXPORTS)]
+            #[linkme(crate = neon::macro_internal::linkme)]
+            fn #exported_name<'cx>(
+                cx: &mut neon::context::ModuleContext<'cx>,
+            ) -> neon::result::NeonResult<(&'cx str, neon::handle::Handle<'cx, neon::types::JsValue>)> {
+                neon::types::JsFunction::new(cx, #name).map(|v| (
+                    stringify!(#name),
+                    neon::handle::Handle::upcast(&v),
+                ))
+            }
+
+            #block
+        }
+    )
+    .into()
+}

crates/neon/Cargo.toml

@@ -26,6 +26,7 @@ getrandom = { version = "0.2.11", optional = true }
 libloading = "0.8.1"
 semver = "1.0.20"
 smallvec = "1.11.2"
+linkme = "0.3.25"
 once_cell = "1.18.0"
 neon-macros = { version = "=1.0.0", path = "../neon-macros" }
 aquamarine = { version = "0.3.2", optional = true }

crates/neon/src/context/internal.rs

@@ -66,7 +66,13 @@ pub unsafe fn initialize_module(
     let env = Env(env);
     let exports = Handle::new_internal(JsObject::from_local(env, exports.cast()));
 
-    ModuleContext::with(env, exports, |cx| {
+    ModuleContext::with(env, exports, |mut cx| {
+        for create in crate::macro_internal::EXPORTS {
+            if let Ok((k, v)) = create(&mut cx) {
+                let _ = cx.export_value(k, v);
+            }
+        }
+
         let _ = init(cx);
     });
 }

crates/neon/src/macro_internal/mod.rs

@@ -1,3 +1,9 @@
 //! Internals needed by macros. These have to be exported for the macros to work
 
+pub use linkme;
 pub use crate::context::internal::initialize_module;
+
+use crate::{context::ModuleContext, handle::Handle, result::NeonResult, types::JsValue};
+
+#[linkme::distributed_slice]
+pub static EXPORTS: [for<'cx> fn(&mut ModuleContext<'cx>) -> NeonResult<(&'cx str, Handle<'cx, JsValue>)>];

test/napi/src/lib.rs

@@ -400,3 +400,8 @@ fn main(mut cx: ModuleContext) -> NeonResult<()> {
 
     Ok(())
 }
+
+#[neon::export]
+fn hello_world(mut cx: FunctionContext) -> JsResult<JsString> {
+    Ok(cx.string("Hello, World!"))
+}