LibJS: Convert IteratorNext AO to ThrowCompletionOr

4 files changed, 31 insertions, 30 deletions

diff --git a/Userland/Libraries/LibJS/Bytecode/Op.cpp b/Userland/Libraries/LibJS/Bytecode/Op.cpp
index 58a0a96b03..5dc4201ee5 100644
--- a/Userland/Libraries/LibJS/Bytecode/Op.cpp
+++ b/Userland/Libraries/LibJS/Bytecode/Op.cpp
@@ -144,9 +144,10 @@ void IteratorToArray::execute_impl(Bytecode::Interpreter& interpreter) const
     size_t index = 0;
 
     while (true) {
-        auto iterator_result = iterator_next(*iterator);
-        if (!iterator_result)
+        auto iterator_result_or_error = iterator_next(*iterator);
+        if (iterator_result_or_error.is_error())
             return;
+        auto* iterator_result = iterator_result_or_error.release_value();
 
         auto complete = iterator_complete(global_object, *iterator_result);
         if (vm.exception())
@@ -490,7 +491,13 @@ void IteratorNext::execute_impl(Bytecode::Interpreter& interpreter) const
     if (object_or_error.is_error())
         return;
     auto* object = object_or_error.release_value();
-    interpreter.accumulator() = iterator_next(*object);
+
+    auto iterator_result_or_error = iterator_next(*object);
+    if (iterator_result_or_error.is_error())
+        return;
+    auto* iterator_result = iterator_result_or_error.release_value();
+
+    interpreter.accumulator() = iterator_result;
 }
 
 void IteratorResultDone::execute_impl(Bytecode::Interpreter& interpreter) const
diff --git a/Userland/Libraries/LibJS/Runtime/IteratorOperations.cpp b/Userland/Libraries/LibJS/Runtime/IteratorOperations.cpp
index c465b550ee..2dfdeac91e 100644
--- a/Userland/Libraries/LibJS/Runtime/IteratorOperations.cpp
+++ b/Userland/Libraries/LibJS/Runtime/IteratorOperations.cpp
@@ -34,29 +34,24 @@ ThrowCompletionOr<Object*> get_iterator(GlobalObject& global_object, Value value
 }
 
 // 7.4.2 IteratorNext ( iteratorRecord [ , value ] ), https://tc39.es/ecma262/#sec-iteratornext
-Object* iterator_next(Object& iterator, Value value)
+ThrowCompletionOr<Object*> iterator_next(Object& iterator, Value value)
 {
     // FIXME: Implement using iterator records, not ordinary objects
     auto& vm = iterator.vm();
     auto& global_object = iterator.global_object();
 
-    auto next_method = TRY_OR_DISCARD(iterator.get(vm.names.next));
-
-    if (!next_method.is_function()) {
-        vm.throw_exception<TypeError>(global_object, ErrorType::IterableNextNotAFunction);
-        return nullptr;
-    }
+    auto next_method = TRY(iterator.get(vm.names.next));
+    if (!next_method.is_function())
+        return vm.throw_completion<TypeError>(global_object, ErrorType::IterableNextNotAFunction);
 
     Value result;
     if (value.is_empty())
-        result = TRY_OR_DISCARD(vm.call(next_method.as_function(), &iterator));
+        result = TRY(vm.call(next_method.as_function(), &iterator));
     else
-        result = TRY_OR_DISCARD(vm.call(next_method.as_function(), &iterator, value));
+        result = TRY(vm.call(next_method.as_function(), &iterator, value));
 
-    if (!result.is_object()) {
-        vm.throw_exception<TypeError>(global_object, ErrorType::IterableNextBadReturn);
-        return nullptr;
-    }
+    if (!result.is_object())
+        return vm.throw_completion<TypeError>(global_object, ErrorType::IterableNextBadReturn);
 
     return &result.as_object();
 }
@@ -84,9 +79,7 @@ Object* iterator_step(GlobalObject& global_object, Object& iterator)
 {
     auto& vm = global_object.vm();
 
-    auto result = iterator_next(iterator);
-    if (vm.exception())
-        return {};
+    auto result = TRY_OR_DISCARD(iterator_next(iterator));
 
     auto done = iterator_complete(global_object, *result);
     if (vm.exception())
@@ -176,9 +169,10 @@ void get_iterator_values(GlobalObject& global_object, Value value, Function<Iter
     auto* iterator = iterator_or_error.release_value();
 
     while (true) {
-        auto next_object = iterator_next(*iterator);
-        if (!next_object)
+        auto next_object_or_error = iterator_next(*iterator);
+        if (next_object_or_error.is_error())
             return;
+        auto* next_object = next_object_or_error.release_value();
 
         auto done_property_or_error = next_object->get(vm.names.done);
         if (done_property_or_error.is_error())
diff --git a/Userland/Libraries/LibJS/Runtime/IteratorOperations.h b/Userland/Libraries/LibJS/Runtime/IteratorOperations.h
index b77d46909c..d53ef65339 100644
--- a/Userland/Libraries/LibJS/Runtime/IteratorOperations.h
+++ b/Userland/Libraries/LibJS/Runtime/IteratorOperations.h
@@ -20,7 +20,7 @@ enum class IteratorHint {
 };
 
 ThrowCompletionOr<Object*> get_iterator(GlobalObject&, Value value, IteratorHint hint = IteratorHint::Sync, Value method = {});
-Object* iterator_next(Object& iterator, Value value = {});
+ThrowCompletionOr<Object*> iterator_next(Object& iterator, Value value = {});
 Object* iterator_step(GlobalObject&, Object& iterator);
 bool iterator_complete(GlobalObject&, Object& iterator_result);
 Value iterator_value(GlobalObject&, Object& iterator_result);
diff --git a/Userland/Libraries/LibJS/Runtime/VM.cpp b/Userland/Libraries/LibJS/Runtime/VM.cpp
index 22b9e5cef9..5e8dc951a8 100644
--- a/Userland/Libraries/LibJS/Runtime/VM.cpp
+++ b/Userland/Libraries/LibJS/Runtime/VM.cpp
@@ -359,12 +359,12 @@ ThrowCompletionOr<void> VM::iterator_binding_initialization(BindingPattern const
 
             auto* array = Array::create(global_object, 0);
             while (!iterator_done) {
-                auto next_object = iterator_next(*iterator);
-                if (!next_object) {
+                auto next_object_or_error = iterator_next(*iterator);
+                if (next_object_or_error.is_throw_completion()) {
                     iterator_done = true;
-                    VERIFY(exception());
-                    return JS::throw_completion(exception()->value());
+                    return JS::throw_completion(next_object_or_error.release_error().value());
                 }
+                auto* next_object = next_object_or_error.release_value();
 
                 auto done_property = TRY(next_object->get(names.done));
                 if (done_property.to_boolean()) {
@@ -378,12 +378,12 @@ ThrowCompletionOr<void> VM::iterator_binding_initialization(BindingPattern const
             value = array;
 
         } else if (!iterator_done) {
-            auto next_object = iterator_next(*iterator);
-            if (!next_object) {
+            auto next_object_or_error = iterator_next(*iterator);
+            if (next_object_or_error.is_throw_completion()) {
                 iterator_done = true;
-                VERIFY(exception());
-                return JS::throw_completion(exception()->value());
+                return JS::throw_completion(next_object_or_error.release_error().value());
             }
+            auto* next_object = next_object_or_error.release_value();
 
             auto done_property = TRY(next_object->get(names.done));
             if (done_property.to_boolean()) {