Add exception to rejection logic in `generic_call` (#32950)

* exception in JS Promise

Signed-off-by: sagudev <16504129+sagudev@users.noreply.github.com>

* EXCEPTION_TO_REJECTION on generic_call

Signed-off-by: sagudev <16504129+sagudev@users.noreply.github.com>

* PromiseRejectionEvent should handle promise as object

Signed-off-by: sagudev <16504129+sagudev@users.noreply.github.com>

* expectations

Signed-off-by: sagudev <16504129+sagudev@users.noreply.github.com>

---------

Signed-off-by: sagudev <16504129+sagudev@users.noreply.github.com>

2 files changed, 30 insertions, 14 deletions

diff --git a/components/script/dom/bindings/codegen/CodegenRust.py b/components/script/dom/bindings/codegen/CodegenRust.py
index fa77c516abb..154ec01c7ae 100644
--- a/components/script/dom/bindings/codegen/CodegenRust.py
+++ b/components/script/dom/bindings/codegen/CodegenRust.py
@@ -1870,13 +1870,17 @@ class MethodDefiner(PropertyDefiner):
             else:
                 selfHostedName = "0 as *const libc::c_char"
                 if m.get("methodInfo", True):
+                    if m.get("returnsPromise", False):
+                        exceptionToRejection = "true"
+                    else:
+                        exceptionToRejection = "false"
                     identifier = m.get("nativeName", m["name"])
                     # Go through an intermediate type here, because it's not
                     # easy to tell whether the methodinfo is a JSJitInfo or
                     # a JSTypedMethodJitInfo here.  The compiler knows, though,
                     # so let it do the work.
                     jitinfo = "&%s_methodinfo as *const _ as *const JSJitInfo" % identifier
-                    accessor = "Some(generic_method)"
+                    accessor = f"Some(generic_method::<{exceptionToRejection}>)"
                 else:
                     if m.get("returnsPromise", False):
                         jitinfo = "&%s_methodinfo" % m.get("nativeName", m["name"])
@@ -1977,10 +1981,14 @@ class AttrDefiner(PropertyDefiner):
                 accessor = 'get_' + self.descriptor.internalNameFor(attr.identifier.name)
                 jitinfo = "0 as *const JSJitInfo"
             else:
+                if attr.type.isPromise():
+                    exceptionToRejection = "true"
+                else:
+                    exceptionToRejection = "false"
                 if attr.hasLegacyLenientThis():
-                    accessor = "generic_lenient_getter"
+                    accessor = f"generic_lenient_getter::<{exceptionToRejection}>"
                 else:
-                    accessor = "generic_getter"
+                    accessor = f"generic_getter::<{exceptionToRejection}>"
                 jitinfo = "&%s_getterinfo" % self.descriptor.internalNameFor(attr.identifier.name)
 
             return ("JSNativeWrapper { op: Some(%(native)s), info: %(info)s }"
diff --git a/components/script/dom/bindings/utils.rs b/components/script/dom/bindings/utils.rs
index 764e604620c..07424ff6d3f 100644
--- a/components/script/dom/bindings/utils.rs
+++ b/components/script/dom/bindings/utils.rs
@@ -466,7 +466,7 @@ pub unsafe fn delete_property_by_id(
     JS_DeletePropertyById(cx, object, id, bp)
 }
 
-unsafe fn generic_call(
+unsafe fn generic_call<const EXCEPTION_TO_REJECTION: bool>(
     cx: *mut JSContext,
     argc: libc::c_uint,
     vp: *mut JSVal,
@@ -488,7 +488,11 @@ unsafe fn generic_call(
     let thisobj = args.thisv();
     if !thisobj.get().is_null_or_undefined() && !thisobj.get().is_object() {
         throw_invalid_this(cx, proto_id);
-        return false;
+        return if EXCEPTION_TO_REJECTION {
+            exception_to_promise(cx, args.rval())
+        } else {
+            false
+        };
     }
 
     rooted!(in(cx) let obj = if thisobj.get().is_object() {
@@ -507,7 +511,11 @@ unsafe fn generic_call(
                 return true;
             } else {
                 throw_invalid_this(cx, proto_id);
-                return false;
+                return if EXCEPTION_TO_REJECTION {
+                    exception_to_promise(cx, args.rval())
+                } else {
+                    false
+                };
             }
         },
     };
@@ -522,30 +530,30 @@ unsafe fn generic_call(
 }
 
 /// Generic method of IDL interface.
-pub unsafe extern "C" fn generic_method(
+pub unsafe extern "C" fn generic_method<const EXCEPTION_TO_REJECTION: bool>(
     cx: *mut JSContext,
     argc: libc::c_uint,
     vp: *mut JSVal,
 ) -> bool {
-    generic_call(cx, argc, vp, false, CallJitMethodOp)
+    generic_call::<EXCEPTION_TO_REJECTION>(cx, argc, vp, false, CallJitMethodOp)
 }
 
 /// Generic getter of IDL interface.
-pub unsafe extern "C" fn generic_getter(
+pub unsafe extern "C" fn generic_getter<const EXCEPTION_TO_REJECTION: bool>(
     cx: *mut JSContext,
     argc: libc::c_uint,
     vp: *mut JSVal,
 ) -> bool {
-    generic_call(cx, argc, vp, false, CallJitGetterOp)
+    generic_call::<EXCEPTION_TO_REJECTION>(cx, argc, vp, false, CallJitGetterOp)
 }
 
 /// Generic lenient getter of IDL interface.
-pub unsafe extern "C" fn generic_lenient_getter(
+pub unsafe extern "C" fn generic_lenient_getter<const EXCEPTION_TO_REJECTION: bool>(
     cx: *mut JSContext,
     argc: libc::c_uint,
     vp: *mut JSVal,
 ) -> bool {
-    generic_call(cx, argc, vp, true, CallJitGetterOp)
+    generic_call::<EXCEPTION_TO_REJECTION>(cx, argc, vp, true, CallJitGetterOp)
 }
 
 unsafe extern "C" fn call_setter(
@@ -569,7 +577,7 @@ pub unsafe extern "C" fn generic_setter(
     argc: libc::c_uint,
     vp: *mut JSVal,
 ) -> bool {
-    generic_call(cx, argc, vp, false, call_setter)
+    generic_call::<false>(cx, argc, vp, false, call_setter)
 }
 
 /// Generic lenient setter of IDL interface.
@@ -578,7 +586,7 @@ pub unsafe extern "C" fn generic_lenient_setter(
     argc: libc::c_uint,
     vp: *mut JSVal,
 ) -> bool {
-    generic_call(cx, argc, vp, true, call_setter)
+    generic_call::<false>(cx, argc, vp, true, call_setter)
 }
 
 unsafe extern "C" fn instance_class_has_proto_at_depth(