LibJS: Convert NativeFunction::{call,construct}() to ThrowCompletionOr

Both at the same time because many of them call construct() in call()
and I'm not keen on adding a bunch of temporary plumbing to turn
exceptions into throw completions.
Also changes the return value of construct() to Object* instead of Value
as it always needs to return an object; allowing an arbitrary Value is a
massive foot gun.

2 files changed, 7 insertions, 8 deletions

diff --git a/Userland/Libraries/LibWeb/Bindings/ImageConstructor.cpp b/Userland/Libraries/LibWeb/Bindings/ImageConstructor.cpp
index 3260bba7cc..9acff1182c 100644
--- a/Userland/Libraries/LibWeb/Bindings/ImageConstructor.cpp
+++ b/Userland/Libraries/LibWeb/Bindings/ImageConstructor.cpp
@@ -33,26 +33,25 @@ ImageConstructor::~ImageConstructor()
 {
 }
 
-JS::Value ImageConstructor::call()
+JS::ThrowCompletionOr<JS::Value> ImageConstructor::call()
 {
-    vm().throw_exception<JS::TypeError>(global_object(), JS::ErrorType::ConstructorWithoutNew, "Image");
-    return {};
+    return vm().throw_completion<JS::TypeError>(global_object(), JS::ErrorType::ConstructorWithoutNew, "Image");
 }
 
 // https://html.spec.whatwg.org/multipage/embedded-content.html#dom-image
-JS::Value ImageConstructor::construct(FunctionObject&)
+JS::ThrowCompletionOr<JS::Object*> ImageConstructor::construct(FunctionObject&)
 {
     auto& window = static_cast<WindowObject&>(global_object());
     auto& document = window.impl().associated_document();
     auto image_element = DOM::create_element(document, HTML::TagNames::img, Namespace::HTML);
 
     if (vm().argument_count() > 0) {
-        u32 width = TRY_OR_DISCARD(vm().argument(0).to_u32(global_object()));
+        u32 width = TRY(vm().argument(0).to_u32(global_object()));
         image_element->set_attribute(HTML::AttributeNames::width, String::formatted("{}", width));
     }
 
     if (vm().argument_count() > 1) {
-        u32 height = TRY_OR_DISCARD(vm().argument(1).to_u32(global_object()));
+        u32 height = TRY(vm().argument(1).to_u32(global_object()));
         image_element->set_attribute(HTML::AttributeNames::height, String::formatted("{}", height));
     }
 
diff --git a/Userland/Libraries/LibWeb/Bindings/ImageConstructor.h b/Userland/Libraries/LibWeb/Bindings/ImageConstructor.h
index 54959d0cab..b516216cfd 100644
--- a/Userland/Libraries/LibWeb/Bindings/ImageConstructor.h
+++ b/Userland/Libraries/LibWeb/Bindings/ImageConstructor.h
@@ -16,8 +16,8 @@ public:
     virtual void initialize(JS::GlobalObject&) override;
     virtual ~ImageConstructor() override;
 
-    virtual JS::Value call() override;
-    virtual JS::Value construct(JS::FunctionObject& new_target) override;
+    virtual JS::ThrowCompletionOr<JS::Value> call() override;
+    virtual JS::ThrowCompletionOr<JS::Object*> construct(JS::FunctionObject& new_target) override;
 
 private:
     virtual bool has_constructor() const override { return true; }