LibJS: Implement the GetMethod() abstract operation as a Value method

This was a standalone function previously (get_method()), but instead of
passing a Value to it, we can just make it a method.

Also add spec step comments and fix the receiver value by using GetV().

Userland/Libraries/LibJS/Runtime/AbstractOperations.cpp

@@ -39,25 +39,6 @@ Value require_object_coercible(GlobalObject& global_object, Value value)
     return value;
 }
 
-// 7.3.10 GetMethod ( V, P ), https://tc39.es/ecma262/#sec-getmethod
-Function* get_method(GlobalObject& global_object, Value value, PropertyName const& property_name)
-{
-    auto& vm = global_object.vm();
-    auto* object = value.to_object(global_object);
-    if (vm.exception())
-        return nullptr;
-    auto property_value = object->get(property_name);
-    if (vm.exception())
-        return nullptr;
-    if (property_value.is_empty() || property_value.is_nullish())
-        return nullptr;
-    if (!property_value.is_function()) {
-        vm.throw_exception<TypeError>(global_object, ErrorType::NotAFunction, property_value.to_string_without_side_effects());
-        return nullptr;
-    }
-    return &property_value.as_function();
-}
-
 // 7.3.18 LengthOfArrayLike ( obj ), https://tc39.es/ecma262/#sec-lengthofarraylike
 size_t length_of_array_like(GlobalObject& global_object, Object const& object)
 {

Userland/Libraries/LibJS/Runtime/AbstractOperations.h

@@ -18,7 +18,6 @@ ObjectEnvironmentRecord* new_object_environment(Object&, bool is_with_environmen
 EnvironmentRecord& get_this_environment(VM&);
 Object* get_super_constructor(VM&);
 Value require_object_coercible(GlobalObject&, Value);
-Function* get_method(GlobalObject& global_object, Value, PropertyName const&);
 size_t length_of_array_like(GlobalObject&, Object const&);
 MarkedValueList create_list_from_array_like(GlobalObject&, Value, AK::Function<Result<void, ErrorType>(Value)> = {});
 Function* species_constructor(GlobalObject&, Object const&, Function& default_constructor);

Userland/Libraries/LibJS/Runtime/IteratorOperations.cpp

@@ -101,7 +101,7 @@ void iterator_close(Object& iterator)
             vm.unwind(unwind_until, unwind_until_label);
     };
 
-    auto return_method = get_method(global_object, &iterator, vm.names.return_);
+    auto return_method = Value(&iterator).get_method(global_object, vm.names.return_);
     if (!return_method)
         return restore_completion(); // If return is undefined, return Completion(completion).
 

Userland/Libraries/LibJS/Runtime/ProxyObject.cpp

@@ -62,7 +62,7 @@ Object* ProxyObject::prototype()
         vm.throw_exception<TypeError>(global_object(), ErrorType::ProxyRevoked);
         return nullptr;
     }
-    auto trap = get_method(global_object(), Value(&m_handler), vm.names.getPrototypeOf);
+    auto trap = Value(&m_handler).get_method(global_object(), vm.names.getPrototypeOf);
     if (vm.exception())
         return nullptr;
     if (!trap)
@@ -108,7 +108,7 @@ bool ProxyObject::set_prototype(Object* object)
         vm.throw_exception<TypeError>(global_object(), ErrorType::ProxyRevoked);
         return false;
     }
-    auto trap = get_method(global_object(), Value(&m_handler), vm.names.setPrototypeOf);
+    auto trap = Value(&m_handler).get_method(global_object(), vm.names.setPrototypeOf);
     if (vm.exception())
         return false;
     if (!trap)
@@ -135,7 +135,7 @@ bool ProxyObject::is_extensible() const
         vm.throw_exception<TypeError>(global_object(), ErrorType::ProxyRevoked);
         return false;
     }
-    auto trap = get_method(global_object(), Value(&m_handler), vm.names.isExtensible);
+    auto trap = Value(&m_handler).get_method(global_object(), vm.names.isExtensible);
     if (vm.exception())
         return false;
     if (!trap)
@@ -158,7 +158,7 @@ bool ProxyObject::prevent_extensions()
         vm.throw_exception<TypeError>(global_object(), ErrorType::ProxyRevoked);
         return false;
     }
-    auto trap = get_method(global_object(), Value(&m_handler), vm.names.preventExtensions);
+    auto trap = Value(&m_handler).get_method(global_object(), vm.names.preventExtensions);
     if (vm.exception())
         return false;
     if (!trap)
@@ -181,7 +181,7 @@ Optional<PropertyDescriptor> ProxyObject::get_own_property_descriptor(const Prop
         vm.throw_exception<TypeError>(global_object(), ErrorType::ProxyRevoked);
         return {};
     }
-    auto trap = get_method(global_object(), Value(&m_handler), vm.names.getOwnPropertyDescriptor);
+    auto trap = Value(&m_handler).get_method(global_object(), vm.names.getOwnPropertyDescriptor);
     if (vm.exception())
         return {};
     if (!trap)
@@ -232,7 +232,7 @@ bool ProxyObject::define_property(const StringOrSymbol& property_name, const Obj
         vm.throw_exception<TypeError>(global_object(), ErrorType::ProxyRevoked);
         return false;
     }
-    auto trap = get_method(global_object(), Value(&m_handler), vm.names.defineProperty);
+    auto trap = Value(&m_handler).get_method(global_object(), vm.names.defineProperty);
     if (vm.exception())
         return false;
     if (!trap)
@@ -279,7 +279,7 @@ bool ProxyObject::has_property(const PropertyName& name) const
         vm.throw_exception<TypeError>(global_object(), ErrorType::ProxyRevoked);
         return false;
     }
-    auto trap = get_method(global_object(), Value(&m_handler), vm.names.has);
+    auto trap = Value(&m_handler).get_method(global_object(), vm.names.has);
     if (vm.exception())
         return false;
     if (!trap)
@@ -319,7 +319,7 @@ Value ProxyObject::get(const PropertyName& name, Value receiver, AllowSideEffect
     }
     if (receiver.is_empty())
         receiver = Value(const_cast<ProxyObject*>(this));
-    auto trap = get_method(global_object(), Value(&m_handler), vm.names.get);
+    auto trap = Value(&m_handler).get_method(global_object(), vm.names.get);
     if (vm.exception())
         return {};
     if (!trap)
@@ -352,7 +352,7 @@ bool ProxyObject::put(const PropertyName& name, Value value, Value receiver)
     }
     if (receiver.is_empty())
         receiver = Value(const_cast<ProxyObject*>(this));
-    auto trap = get_method(global_object(), Value(&m_handler), vm.names.set);
+    auto trap = Value(&m_handler).get_method(global_object(), vm.names.set);
     if (vm.exception())
         return false;
     if (!trap)
@@ -382,7 +382,7 @@ bool ProxyObject::delete_property(PropertyName const& name, bool force_throw_exc
         vm.throw_exception<TypeError>(global_object(), ErrorType::ProxyRevoked);
         return false;
     }
-    auto trap = get_method(global_object(), Value(&m_handler), vm.names.deleteProperty);
+    auto trap = Value(&m_handler).get_method(global_object(), vm.names.deleteProperty);
     if (vm.exception())
         return false;
     if (!trap)
@@ -422,7 +422,7 @@ Value ProxyObject::call()
         vm.throw_exception<TypeError>(global_object(), ErrorType::ProxyRevoked);
         return {};
     }
-    auto trap = get_method(global_object(), Value(&m_handler), vm.names.apply);
+    auto trap = Value(&m_handler).get_method(global_object(), vm.names.apply);
     if (vm.exception())
         return {};
     if (!trap)
@@ -451,7 +451,7 @@ Value ProxyObject::construct(Function& new_target)
         vm.throw_exception<TypeError>(global_object(), ErrorType::ProxyRevoked);
         return {};
     }
-    auto trap = get_method(global_object(), Value(&m_handler), vm.names.construct);
+    auto trap = Value(&m_handler).get_method(global_object(), vm.names.construct);
     if (vm.exception())
         return {};
     if (!trap)

Userland/Libraries/LibJS/Runtime/RegExpPrototype.cpp

@@ -262,7 +262,7 @@ JS_DEFINE_NATIVE_FUNCTION(RegExpPrototype::symbol_match)
         return {};
     bool global = global_value.to_boolean();
     // FIXME: Implement and use RegExpExec, this does something different - https://tc39.es/ecma262/#sec-regexpexec
-    auto* exec = get_method(global_object, rx, vm.names.exec);
+    auto* exec = Value(rx).get_method(global_object, vm.names.exec);
     if (!exec)
         return js_undefined();
     // FIXME end
@@ -295,7 +295,7 @@ JS_DEFINE_NATIVE_FUNCTION(RegExpPrototype::symbol_replace)
         rx->regex().start_offset = 0;
 
     // FIXME: Implement and use RegExpExec - https://tc39.es/ecma262/#sec-regexpexec
-    auto* exec = get_method(global_object, rx, vm.names.exec);
+    auto* exec = Value(rx).get_method(global_object, vm.names.exec);
     if (!exec)
         return {};
 

Userland/Libraries/LibJS/Runtime/StringPrototype.cpp

@@ -702,7 +702,7 @@ JS_DEFINE_NATIVE_FUNCTION(StringPrototype::match)
         return {};
     auto regexp = vm.argument(0);
     if (!regexp.is_nullish()) {
-        if (auto* matcher = get_method(global_object, regexp, *vm.well_known_symbol_match()))
+        if (auto* matcher = regexp.get_method(global_object, *vm.well_known_symbol_match()))
             return vm.call(*matcher, regexp, this_object);
     }
     auto s = this_object.to_string(global_object);
@@ -740,7 +740,7 @@ JS_DEFINE_NATIVE_FUNCTION(StringPrototype::match_all)
                 return {};
             }
         }
-        if (auto* matcher = get_method(global_object, regexp, *vm.well_known_symbol_match_all()))
+        if (auto* matcher = regexp.get_method(global_object, *vm.well_known_symbol_match_all()))
             return vm.call(*matcher, regexp, this_object);
         if (vm.exception())
             return {};
@@ -764,7 +764,7 @@ JS_DEFINE_NATIVE_FUNCTION(StringPrototype::replace)
     auto replace_value = vm.argument(1);
 
     if (!search_value.is_nullish()) {
-        if (auto* replacer = get_method(global_object, search_value, *vm.well_known_symbol_replace()))
+        if (auto* replacer = search_value.get_method(global_object, *vm.well_known_symbol_replace()))
             return vm.call(*replacer, search_value, this_object, replace_value);
     }
 
@@ -812,7 +812,7 @@ JS_DEFINE_NATIVE_FUNCTION(StringPrototype::search)
         return {};
     auto regexp = vm.argument(0);
     if (!regexp.is_nullish()) {
-        if (auto* searcher = get_method(global_object, regexp, *vm.well_known_symbol_search()))
+        if (auto* searcher = regexp.get_method(global_object, *vm.well_known_symbol_search()))
             return vm.call(*searcher, regexp, this_object);
         if (vm.exception())
             return {};

Userland/Libraries/LibJS/Runtime/Value.cpp

@@ -413,7 +413,7 @@ Value Value::to_primitive(GlobalObject& global_object, PreferredType preferred_t
     };
     if (is_object()) {
         auto& vm = global_object.vm();
-        auto to_primitive_method = get_method(global_object, *this, *vm.well_known_symbol_to_primitive());
+        auto to_primitive_method = get_method(global_object, *vm.well_known_symbol_to_primitive());
         if (vm.exception())
             return {};
         if (to_primitive_method) {
@@ -805,6 +805,32 @@ Value Value::get(GlobalObject& global_object, PropertyName const& property_name)
     return object->get(property_name, *this);
 }
 
+// 7.3.10 GetMethod ( V, P ), https://tc39.es/ecma262/#sec-getmethod
+Function* Value::get_method(GlobalObject& global_object, PropertyName const& property_name) const
+{
+    auto& vm = global_object.vm();
+
+    // 1. Assert: IsPropertyKey(P) is true.
+
+    // 2. Let func be ? GetV(V, P).
+    auto function = get(global_object, property_name).value_or(js_undefined());
+    if (vm.exception())
+        return nullptr;
+
+    // 3. If func is either undefined or null, return undefined.
+    if (function.is_nullish())
+        return nullptr;
+
+    // 4. If IsCallable(func) is false, throw a TypeError exception.
+    if (!function.is_function()) {
+        vm.throw_exception<TypeError>(global_object, ErrorType::NotAFunction, function.to_string_without_side_effects());
+        return nullptr;
+    }
+
+    // 5. Return func.
+    return &function.as_function();
+}
+
 // 13.10 Relational Operators, https://tc39.es/ecma262/#sec-relational-operators
 Value greater_than(GlobalObject& global_object, Value lhs, Value rhs)
 {
@@ -1204,7 +1230,7 @@ Value instance_of(GlobalObject& global_object, Value lhs, Value rhs)
         vm.throw_exception<TypeError>(global_object, ErrorType::NotAnObject, rhs.to_string_without_side_effects());
         return {};
     }
-    auto has_instance_method = get_method(global_object, Value(&rhs.as_object()), *vm.well_known_symbol_has_instance());
+    auto has_instance_method = rhs.get_method(global_object, *vm.well_known_symbol_has_instance());
     if (vm.exception())
         return {};
     if (has_instance_method) {

Userland/Libraries/LibJS/Runtime/Value.h

@@ -288,6 +288,7 @@ public:
     bool to_boolean() const;
 
     Value get(GlobalObject&, PropertyName const&) const;
+    Function* get_method(GlobalObject&, PropertyName const&) const;
 
     String to_string_without_side_effects() const;