LibJS: Convert Interpreter::run() to ThrowCompletionOr<Value>

Instead of making it a void function, checking for an exception, and
then receiving the relevant result via VM::last_value(), we can
consolidate all of this by using completions.

This allows us to remove more uses of VM::exception(), and all uses of
VM::last_value().

1 files changed, 7 insertions, 1 deletions

diff --git a/Userland/Libraries/LibJS/Interpreter.cpp b/Userland/Libraries/LibJS/Interpreter.cpp
index eb1cc9df18..bcd17733b2 100644
--- a/Userland/Libraries/LibJS/Interpreter.cpp
+++ b/Userland/Libraries/LibJS/Interpreter.cpp
@@ -38,7 +38,7 @@ Interpreter::~Interpreter()
 {
 }
 
-void Interpreter::run(GlobalObject& global_object, const Program& program)
+ThrowCompletionOr<Value> Interpreter::run(GlobalObject& global_object, const Program& program)
 {
     // FIXME: Why does this receive a GlobalObject? Interpreter has one already, and this might not be in sync with the Realm's GlobalObject.
 
@@ -71,6 +71,12 @@ void Interpreter::run(GlobalObject& global_object, const Program& program)
     vm.pop_execution_context();
 
     vm.finish_execution_generation();
+
+    if (completion.is_abrupt()) {
+        VERIFY(completion.type() == Completion::Type::Throw);
+        return completion.release_error();
+    }
+    return completion.value().value_or(js_undefined());
 }
 
 GlobalObject& Interpreter::global_object()