Better arity checks for overloads

Source/bindings/templates/methods.cpp

 {##############################################################################}
 {% macro generate_method(method, world_suffix) %}
 {% filter conditional(method.conditional_string) %}
 static void {{method.name}}{{method.overload_index}}Method{{world_suffix}}(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     {# Local variables #}
     {% if method.has_exception_state %}
     ExceptionState exceptionState(ExceptionState::ExecutionContext, "{{method.name}}", "{{interface_name}}", info.Holder(), info.GetIsolate());
     {% endif %}
     {# Overloaded methods have length checked during overload resolution #}
     {% if method.number_of_required_arguments and not method.overload_index %}
     if (UNLIKELY(info.Length() < {{method.number_of_required_arguments}})) {
-        {{throw_arity_type_error(method, method.number_of_required_arguments)}};
+        {{throw_minimum_arity_type_error(method, method.number_of_required_arguments)}};
         return;
     }
     {% endif %}
     {% if not method.is_static %}
     {{cpp_class}}* impl = {{v8_class}}::toNative(info.Holder());
     {% endif %}
     {% if method.is_custom_element_callbacks %}
     CustomElementCallbackDispatcher::CallbackDeliveryScope deliveryScope;
     {% endif %}
     {# Security checks #}
@@ skipping 236 matching lines @@
 exceptionState.throwIfNeeded();
 {%- elif method.is_constructor %}
 throwTypeError(ExceptionMessages::failedToConstruct("{{interface_name}}", {{error_message}}), info.GetIsolate());
 {%- else %}
 throwTypeError(ExceptionMessages::failedToExecute("{{method.name}}", "{{interface_name}}", {{error_message}}), info.GetIsolate());
 {%- endif %}
 {% endmacro %}
 
 
 {######################################}
-{% macro throw_arity_type_error(method, number_of_required_arguments) %}
+{% macro throw_arity_type_error(method, valid_arities) %}
 {% if method.has_exception_state %}
-throwArityTypeError(exceptionState, {{number_of_required_arguments}}, info.Length())
+throwArityTypeError(exceptionState, {{valid_arities}}, info.Length())
 {%- elif method.is_constructor %}
-throwArityTypeErrorForConstructor("{{interface_name}}", {{number_of_required_arguments}}, info.Length(), info.GetIsolate())
+throwArityTypeErrorForConstructor("{{interface_name}}", {{valid_arities}}, info.Length(), info.GetIsolate())
 {%- else %}
-throwArityTypeErrorForMethod("{{method.name}}", "{{interface_name}}", {{number_of_required_arguments}}, info.Length(), info.GetIsolate())
+throwArityTypeErrorForMethod("{{method.name}}", "{{interface_name}}", {{valid_arities}}, info.Length(), info.GetIsolate())
 {%- endif %}
 {% endmacro %}
 
+
+{######################################}
+{% macro throw_minimum_arity_type_error(method, number_of_required_arguments) %}
+{% if method.has_exception_state %}
+throwMinimumArityTypeError(exceptionState, {{number_of_required_arguments}}, info.Length())
+{%- elif method.is_constructor %}
+throwMinimumArityTypeErrorForConstructor("{{interface_name}}", {{number_of_required_arguments}}, info.Length(), info.GetIsolate())
+{%- else %}
+throwMinimumArityTypeErrorForMethod("{{method.name}}", "{{interface_name}}", {{number_of_required_arguments}}, info.Length(), info.GetIsolate())
+{%- endif %}
+{% endmacro %}
+
 
 {##############################################################################}
 {% macro overload_resolution_method(overloads, world_suffix) %}
 static void {{overloads.name}}Method{{world_suffix}}(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Isolate* isolate = info.GetIsolate();
     ExceptionState exceptionState(ExceptionState::ExecutionContext, "{{overloads.name}}", "{{interface_name}}", info.Holder(), isolate);
     {% if overloads.measure_all_as %}
     UseCounter::count(callingExecutionContext(isolate), UseCounter::{{overloads.measure_all_as}});
     {% endif %}
@@ skipping 16 matching lines @@
             {% endif %}
             {% if method.deprecate_as and not overloads.deprecate_all_as %}
             UseCounter::countDeprecation(callingExecutionContext(isolate), UseCounter::{{method.deprecate_as}});
             {% endif %}
             {{method.name}}{{method.overload_index}}Method{{world_suffix}}(info);
             return;
         }
         {% endfor %}
         break;
     {% endfor %}
+    default:
+        {# Invalid arity, throw error #}
+        {# Report full list of valid arities if gaps and above minimum #}
+        {% if overloads.valid_arities %}
+        if (info.Length() >= {{overloads.minarg}}) {
+            throwArityTypeError(exceptionState, "{{overloads.valid_arities}}", info.Length());
+            return;
+        }
+        {% endif %}
+        {# Otherwise just report "not enough arguments" #}
+        exceptionState.throwTypeError(ExceptionMessages::notEnoughArguments({{overloads.minarg}}, info.Length()));
+        exceptionState.throwIfNeeded();
+        return;
     }
     {# No match, throw error #}
-    {% if overloads.minimum_number_of_required_arguments %}
-    if (UNLIKELY(info.Length() < {{overloads.minimum_number_of_required_arguments}})) {
-        throwArityTypeError(exceptionState, {{overloads.minimum_number_of_required_arguments}}, info.Length());
-        return;
-    }
-    {% endif %}
     exceptionState.throwTypeError("No function was found that matched the signature provided.");
     exceptionState.throwIfNeeded();
 }
 {% endmacro %}
 
 
 {##############################################################################}
 {% macro method_callback(method, world_suffix) %}
 {% filter conditional(method.conditional_string) %}
 static void {{method.name}}MethodCallback{{world_suffix}}(const v8::FunctionCallbackInfo<v8::Value>& info)
@@ skipping 79 matching lines @@
 static void constructor{{constructor.overload_index}}(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     v8::Isolate* isolate = info.GetIsolate();
     {% if constructor.has_exception_state %}
     ExceptionState exceptionState(ExceptionState::ConstructionContext, "{{interface_name}}", info.Holder(), isolate);
     {% endif %}
     {# Overloaded constructors have length checked during overload resolution #}
     {% if interface_length and not constructor.overload_index %}
     {# FIXME: remove UNLIKELY: constructors are expensive, so no difference. #}
     if (UNLIKELY(info.Length() < {{interface_length}})) {
-        {{throw_arity_type_error(constructor, interface_length)}};
+        {{throw_minimum_arity_type_error(constructor, interface_length)}};
         return;
     }
     {% endif %}
     {% for argument in constructor.arguments %}
     {{generate_argument(constructor, argument) | indent}}
     {% endfor %}
     {% if is_constructor_call_with_execution_context %}
     ExecutionContext* context = currentExecutionContext(isolate);
     {% endif %}
     {% if is_constructor_call_with_document %}
@@ skipping 45 matching lines @@
 
     // Make sure the document is added to the DOM Node map. Otherwise, the {{cpp_class}} instance
     // may end up being the only node in the map and get garbage-collected prematurely.
     toV8(document, info.Holder(), isolate);
 
     {% if constructor.has_exception_state %}
     ExceptionState exceptionState(ExceptionState::ConstructionContext, "{{interface_name}}", info.Holder(), isolate);
     {% endif %}
     {% if constructor.number_of_required_arguments %}
     if (UNLIKELY(info.Length() < {{constructor.number_of_required_arguments}})) {
-        {{throw_arity_type_error(constructor, constructor.number_of_required_arguments)}};
+        {{throw_minimum_arity_type_error(constructor, constructor.number_of_required_arguments)}};
         return;
     }
     {% endif %}
     {% for argument in constructor.arguments %}
     {{generate_argument(constructor, argument) | indent}}
     {% endfor %}
     {{constructor.cpp_type}} impl = {{cpp_class}}::createForJSConstructor({{constructor.argument_list | join(', ')}});
     {% if is_constructor_raises_exception %}
     if (exceptionState.throwIfNeeded())
         return;
     {% endif %}
 
     {{generate_constructor_wrapper(constructor) | indent}}
 }
 {% endmacro %}