LibWeb: Let various functions throw if not enough arguments

...instead of handing out null / undefined / empty values.

3 files changed, 9 insertions, 8 deletions

diff --git a/Libraries/LibWeb/Bindings/DocumentWrapper.cpp b/Libraries/LibWeb/Bindings/DocumentWrapper.cpp
index 02431720da..13381d82a7 100644
--- a/Libraries/LibWeb/Bindings/DocumentWrapper.cpp
+++ b/Libraries/LibWeb/Bindings/DocumentWrapper.cpp
@@ -76,7 +76,7 @@ JS::Value DocumentWrapper::get_element_by_id(JS::Interpreter& interpreter)
     if (!document)
         return {};
     if (!interpreter.argument_count())
-        return JS::js_null();
+        return interpreter.throw_exception<JS::TypeError>("getElementById() needs one argument");
     auto id = interpreter.argument(0).to_string(interpreter);
     if (interpreter.exception())
         return {};
@@ -92,7 +92,7 @@ JS::Value DocumentWrapper::query_selector_all(JS::Interpreter& interpreter)
     if (!document)
         return {};
     if (!interpreter.argument_count())
-        return JS::js_null();
+        return interpreter.throw_exception<JS::TypeError>("querySelectorAll() needs one argument");
     auto selector = interpreter.argument(0).to_string(interpreter);
     if (interpreter.exception())
         return {};
diff --git a/Libraries/LibWeb/Bindings/EventTargetWrapper.cpp b/Libraries/LibWeb/Bindings/EventTargetWrapper.cpp
index b34dbb4e74..9157e19cb3 100644
--- a/Libraries/LibWeb/Bindings/EventTargetWrapper.cpp
+++ b/Libraries/LibWeb/Bindings/EventTargetWrapper.cpp
@@ -27,6 +27,7 @@
 #include <AK/FlyString.h>
 #include <AK/Function.h>
 #include <LibJS/Interpreter.h>
+#include <LibJS/Runtime/Error.h>
 #include <LibJS/Runtime/Function.h>
 #include <LibJS/Runtime/GlobalObject.h>
 #include <LibWeb/Bindings/EventListenerWrapper.h>
@@ -54,7 +55,7 @@ JS::Value EventTargetWrapper::add_event_listener(JS::Interpreter& interpreter)
     if (!this_object)
         return {};
     if (interpreter.argument_count() < 2)
-        return JS::js_undefined();
+        return interpreter.throw_exception<JS::TypeError>("addEventListener() needs two arguments");
     auto event_name = interpreter.argument(0).to_string(interpreter);
     if (interpreter.exception())
         return {};
diff --git a/Libraries/LibWeb/Bindings/WindowObject.cpp b/Libraries/LibWeb/Bindings/WindowObject.cpp
index b0a00dac16..7f020fc6e3 100644
--- a/Libraries/LibWeb/Bindings/WindowObject.cpp
+++ b/Libraries/LibWeb/Bindings/WindowObject.cpp
@@ -128,8 +128,8 @@ JS::Value WindowObject::set_interval(JS::Interpreter& interpreter)
     auto* impl = impl_from(interpreter);
     if (!impl)
         return {};
-    if (interpreter.argument_count() < 2)
-        return {};
+    if (!interpreter.argument_count())
+        return interpreter.throw_exception<JS::TypeError>("setInterval() needs at least one argument");
     auto* callback_object = interpreter.argument(0).to_object(interpreter);
     if (!callback_object)
         return {};
@@ -148,7 +148,7 @@ JS::Value WindowObject::set_timeout(JS::Interpreter& interpreter)
     if (!impl)
         return {};
     if (!interpreter.argument_count())
-        return {};
+        return interpreter.throw_exception<JS::TypeError>("setTimeout() needs at least one argument");
     auto* callback_object = interpreter.argument(0).to_object(interpreter);
     if (!callback_object)
         return {};
@@ -172,7 +172,7 @@ JS::Value WindowObject::request_animation_frame(JS::Interpreter& interpreter)
     if (!impl)
         return {};
     if (!interpreter.argument_count())
-        return {};
+        return interpreter.throw_exception<JS::TypeError>("requestAnimationFrame() needs one argument");
     auto* callback_object = interpreter.argument(0).to_object(interpreter);
     if (!callback_object)
         return {};
@@ -187,7 +187,7 @@ JS::Value WindowObject::cancel_animation_frame(JS::Interpreter& interpreter)
     if (!impl)
         return {};
     if (!interpreter.argument_count())
-        return {};
+        return interpreter.throw_exception<JS::TypeError>("cancelAnimationFrame() needs one argument");
     auto id = interpreter.argument(0).to_i32(interpreter);
     if (interpreter.exception())
         return {};