[oden-js] Track rejected promises, panic on unhandled rejections

oden-js/src/runtime.rs

@@ -1,7 +1,8 @@
 use crate::{
     module::loader::{load_module, DefaultModuleLoader, ModuleLoader},
     promise::{PromiseEvent, PromiseHandle},
-    ContextRef, Promise, Result, Value,
+    ContextRef, DefaultRejectedPromiseTracker, Promise, RejectedPromiseTracker, Result, Value,
+    ValueRef,
 };
 use oden_js_sys as sys;
 use std::cell::{RefCell, RefMut};
@@ -45,20 +46,19 @@ struct PrivateState {
     promise_send: Sender<(PromiseHandle, PromiseEvent)>,
     promise_recv: Receiver<(PromiseHandle, PromiseEvent)>,
     promise_table: HashMap<PromiseHandle, PromiseEntry>, // !
+    rejection_tracker: Arc<Box<dyn RejectedPromiseTracker>>,
 }
 
 impl PrivateState {
-    pub fn new<T>(loader: T) -> Box<RefCell<Self>>
-    where
-        T: ModuleLoader + 'static,
-    {
+    pub fn new() -> Box<RefCell<Self>> {
         let (send, recv) = channel();
         Box::new(RefCell::new(PrivateState {
             refs: 1,
-            loader: Arc::new(Box::new(loader)),
+            loader: Arc::new(Box::new(DefaultModuleLoader::new())),
             promise_send: send,
             promise_recv: recv,
             promise_table: HashMap::new(),
+            rejection_tracker: Arc::new(Box::new(DefaultRejectedPromiseTracker::new())),
         }))
     }
 
@@ -92,6 +92,28 @@ impl PrivateState {
         let context = ContextRef::from_raw(ctx);
         load_module(&context, path, &loader)
     }
+
+    unsafe extern "C" fn promise_rejection_tracker(
+        ctx: *mut sys::JSContext,
+        promise: sys::JSValue,
+        reason: sys::JSValue,
+        is_handled: i32,
+        opaque: *mut std::os::raw::c_void,
+    ) {
+        let ctx = ContextRef::from_raw(ctx);
+        let promise = ValueRef::from_raw(promise);
+        let reason = ValueRef::from_raw(reason);
+        let is_handled = is_handled != 0;
+        let handler = unsafe {
+            let ptr = opaque as *const RefCell<PrivateState>;
+            ptr.as_ref()
+                .expect("We already know this runtime is one of ours!")
+                .borrow()
+                .rejection_tracker
+                .clone()
+        };
+        handler.on_rejected_promise(&ctx, &promise, &reason, is_handled);
+    }
 }
 
 #[derive(Debug)]
@@ -101,16 +123,17 @@ pub struct Runtime {
 
 impl Runtime {
     pub fn new() -> Runtime {
-        Self::with_loader(DefaultModuleLoader::new())
-    }
-
-    pub fn with_loader<TLoader: ModuleLoader + 'static>(loader: TLoader) -> Runtime {
-        let state = PrivateState::new(loader);
+        let state = PrivateState::new();
         let rt = unsafe {
             let rt = sys::JS_NewRuntime();
             let state = Box::into_raw(state) as *mut _;
             sys::JS_SetRuntimeOpaque(rt, state);
             sys::JS_SetModuleLoaderFunc(rt, None, Some(PrivateState::module_loader), state);
+            sys::JS_SetHostPromiseRejectionTracker(
+                rt,
+                Some(PrivateState::promise_rejection_tracker),
+                state,
+            );
             rt
         };
         Runtime { rt }
@@ -141,6 +164,26 @@ impl Runtime {
         }
     }
 
+    /// Set the handler for loading modules. By default this is an instance
+    /// of `DefaultModuleLoader`.
+    pub fn set_module_loader<T>(&mut self, loader: T)
+    where
+        T: ModuleLoader + 'static,
+    {
+        let mut state = unsafe { PrivateState::from_rt_mut(self.rt) };
+        state.loader = Arc::new(Box::new(loader));
+    }
+
+    /// Set a tracker to be notified whenever a promise is rejected. By
+    /// default, this is an instance of `DefaultRejectedPromiseHandler`.
+    pub fn set_rejected_promise_tracker<T>(&mut self, tracker: T)
+    where
+        T: RejectedPromiseTracker + 'static,
+    {
+        let mut state = unsafe { PrivateState::from_rt_mut(self.rt) };
+        state.rejection_tracker = Arc::new(Box::new(tracker));
+    }
+
     pub fn run_gc(&mut self) {
         unsafe {
             sys::JS_RunGC(self.rt);