LibJS: Implement the RequireObjectCoercible abstract operation

Throws an exception if the given value is nullish, returns it otherwise.
We can now gradually replace such manual checks with this function where
applicable.

This also has the advantage that the somewhat useless "ToObject on null
or undefined" will be replaced with "null cannot be converted to an
object" or "undefined cannot be converted to an object". :^)

1 files changed, 12 insertions, 0 deletions

diff --git a/Userland/Libraries/LibJS/Runtime/Value.cpp b/Userland/Libraries/LibJS/Runtime/Value.cpp
index 1801f75245..69e8c3272c 100644
--- a/Userland/Libraries/LibJS/Runtime/Value.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Value.cpp
@@ -1390,4 +1390,16 @@ Object* species_constructor(GlobalObject& global_object, const Object& object, O
     vm.throw_exception<TypeError>(global_object, ErrorType::NotAConstructor, species.to_string_without_side_effects());
     return nullptr;
 }
+
+// 7.2.1 RequireObjectCoercible, https://tc39.es/ecma262/#sec-requireobjectcoercible
+Value require_object_coercible(GlobalObject& global_object, Value value)
+{
+    auto& vm = global_object.vm();
+    if (value.is_nullish()) {
+        vm.throw_exception<TypeError>(global_object, ErrorType::NotObjectCoercible, value.to_string_without_side_effects());
+        return {};
+    }
+    return value;
+}
+
 }