LibJS: Add the Object::define_native_accessor method

This is very similar to Object::define_native_property, but here the
native functions are exported as standalone JS getter and setter
functions, instead of being transparently called by interactions with
the property.

2 files changed, 35 insertions, 0 deletions

diff --git a/Userland/Libraries/LibJS/Runtime/Object.cpp b/Userland/Libraries/LibJS/Runtime/Object.cpp
index 7935cbf358..29df7bf2c3 100644
--- a/Userland/Libraries/LibJS/Runtime/Object.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Object.cpp
@@ -543,6 +543,40 @@ bool Object::define_property(const PropertyName& property_name, Value value, Pro
     return put_own_property(property_name.to_string_or_symbol(), value, attributes, PutOwnPropertyMode::DefineProperty, throw_exceptions);
 }
 
+bool Object::define_native_accessor(const StringOrSymbol& property_name, AK::Function<Value(VM&, GlobalObject&)> getter, AK::Function<Value(VM&, GlobalObject&)> setter, PropertyAttributes attribute)
+{
+    auto& vm = this->vm();
+    String formatted_property_name;
+    if (property_name.is_string()) {
+        formatted_property_name = property_name.as_string();
+    } else {
+        formatted_property_name = String::formatted("[{}]", property_name.as_symbol()->description());
+    }
+    Function* getter_function = nullptr;
+    if (getter) {
+        auto name = String::formatted("get {}", formatted_property_name);
+        getter_function = NativeFunction::create(global_object(), name, move(getter));
+        getter_function->define_property_without_transition(vm.names.length, Value(0), Attribute::Configurable);
+        if (vm.exception())
+            return {};
+        getter_function->define_property_without_transition(vm.names.name, js_string(vm.heap(), name), Attribute::Configurable);
+        if (vm.exception())
+            return {};
+    }
+    Function* setter_function = nullptr;
+    if (setter) {
+        auto name = String::formatted("set {}", formatted_property_name);
+        setter_function = NativeFunction::create(global_object(), name, move(setter));
+        setter_function->define_property_without_transition(vm.names.length, Value(1), Attribute::Configurable);
+        if (vm.exception())
+            return {};
+        setter_function->define_property_without_transition(vm.names.name, js_string(vm.heap(), name), Attribute::Configurable);
+        if (vm.exception())
+            return {};
+    }
+    return define_accessor(property_name, getter_function, setter_function, attribute);
+}
+
 bool Object::define_accessor(const PropertyName& property_name, Function* getter, Function* setter, PropertyAttributes attributes, bool throw_exceptions)
 {
     VERIFY(property_name.is_valid());
diff --git a/Userland/Libraries/LibJS/Runtime/Object.h b/Userland/Libraries/LibJS/Runtime/Object.h
index fa40ef18d9..e69328b969 100644
--- a/Userland/Libraries/LibJS/Runtime/Object.h
+++ b/Userland/Libraries/LibJS/Runtime/Object.h
@@ -95,6 +95,7 @@ public:
 
     bool define_native_function(const StringOrSymbol& property_name, AK::Function<Value(VM&, GlobalObject&)>, i32 length = 0, PropertyAttributes attributes = default_attributes);
     bool define_native_property(const StringOrSymbol& property_name, AK::Function<Value(VM&, GlobalObject&)> getter, AK::Function<void(VM&, GlobalObject&, Value)> setter, PropertyAttributes attributes = default_attributes);
+    bool define_native_accessor(StringOrSymbol const& property_name, AK::Function<Value(VM&, GlobalObject&)> getter, AK::Function<Value(VM&, GlobalObject&)> setter, PropertyAttributes attributes = default_attributes);
 
     void define_properties(Value properties);