LibJS+LibWeb: Add JS::Object::inherits(class_name)

To allow implementing the DOM class hierarchy in JS bindings, this
patch adds an inherits() function that can be used to ask an Object
if it inherits from a specific C++ class (by name).

The necessary overrides are baked into each Object subclass by the
new JS_OBJECT macro, which works similarly to C_OBJECT in LibCore.

Thanks to @Dexesttp for suggesting this approach. :^)

1 files changed, 2 insertions, 1 deletions

diff --git a/Libraries/LibJS/Runtime/BigIntObject.h b/Libraries/LibJS/Runtime/BigIntObject.h
index 5c5a273400..05a3e9db6b 100644
--- a/Libraries/LibJS/Runtime/BigIntObject.h
+++ b/Libraries/LibJS/Runtime/BigIntObject.h
@@ -32,6 +32,8 @@
 namespace JS {
 
 class BigIntObject final : public Object {
+    JS_OBJECT(BigIntObject, Object);
+
 public:
     static BigIntObject* create(GlobalObject&, BigInt&);
 
@@ -46,7 +48,6 @@ public:
 
 private:
     virtual void visit_children(Visitor&) override;
-    virtual const char* class_name() const override { return "BigIntObject"; }
     virtual bool is_bigint_object() const override { return true; }
 
     BigInt& m_bigint;