fix: Make native modules built with Neon work in Bun

Author: kjvalencik

README.md

@@ -49,6 +49,10 @@ Neon projects to 0.10!
 Support for [LTS versions of Node](https://github.com/nodejs/LTS#release-schedule) and current are expected. If you're
 using a different version of Node and believe it should be supported, let us know.
 
+### Bun (experimental)
+
+[Bun](https://bun.sh/) is an alternate JavaScript runtime that targets Node compatibility. In many cases Neon modules will work in bun; however, at the time of this writing, some Node-API functions are [not implemented](https://github.com/Jarred-Sumner/bun/issues/158).
+
 ### Rust
 
 Neon supports Rust stable version 1.18 and higher. We test on the latest stable, beta, and nightly versions of Rust.

crates/neon/src/sys/bindings/functions.rs

@@ -371,19 +371,19 @@ pub(super) unsafe fn load(env: Env) -> Result<(), libloading::Error> {
     // with `Error: Module did not self-register` if N-API does not exist.
     let version = get_version(&host, env).expect("Failed to find N-API version");
 
-    napi1::load(&host, version, 1)?;
+    napi1::load(&host, version, 1);
 
     #[cfg(feature = "napi-4")]
-    napi4::load(&host, version, 4)?;
+    napi4::load(&host, version, 4);
 
     #[cfg(feature = "napi-5")]
-    napi5::load(&host, version, 5)?;
+    napi5::load(&host, version, 5);
 
     #[cfg(feature = "napi-6")]
-    napi6::load(&host, version, 6)?;
+    napi6::load(&host, version, 6);
 
     #[cfg(feature = "napi-8")]
-    napi8::load(&host, version, 8)?;
+    napi8::load(&host, version, 8);
 
     Ok(())
 }

crates/neon/src/sys/bindings/mod.rs

@@ -118,7 +118,7 @@ macro_rules! generate {
 
         #[inline(never)]
         fn panic_load<T>() -> T {
-            panic!("Must load N-API bindings")
+            panic!("Node-API symbol has not been loaded")
         }
 
         static mut NAPI: Napi = {
@@ -139,21 +139,31 @@ macro_rules! generate {
             host: &libloading::Library,
             actual_napi_version: u32,
             expected_napi_version: u32,
-        ) -> Result<(), libloading::Error> {
+        ) {
             assert!(
                 actual_napi_version >= expected_napi_version,
-                "Minimum required N-API version {}, found {}.",
+                "Minimum required Node-API version {}, found {}.",
                 expected_napi_version,
                 actual_napi_version,
             );
 
+            let print_warn = |err| eprintln!("WARN: {}", err);
+
             NAPI = Napi {
                 $(
-                    $name: *host.get(napi_name!($name).as_bytes())?,
+                    $name: match host.get(napi_name!($name).as_bytes()) {
+                        Ok(f) => *f,
+                        // Node compatible runtimes may not have full coverage of Node-API
+                        // (e.g., bun). Instead of failing to start, warn on start and
+                        // panic when the API is called.
+                        // https://github.com/Jarred-Sumner/bun/issues/158
+                        Err(err) => {
+                            print_warn(err);
+                            NAPI.$name
+                        },
+                    },
                 )*
             };
-
-            Ok(())
         }
 
         $(