LibJS: Implement Number.isNaN()

Like the global isNaN() without the number coercion.

1 files changed, 6 insertions, 0 deletions

diff --git a/Libraries/LibJS/Runtime/NumberConstructor.cpp b/Libraries/LibJS/Runtime/NumberConstructor.cpp
index d1e2d8b245..1c1f4cebc8 100644
--- a/Libraries/LibJS/Runtime/NumberConstructor.cpp
+++ b/Libraries/LibJS/Runtime/NumberConstructor.cpp
@@ -41,6 +41,7 @@ NumberConstructor::NumberConstructor()
     : NativeFunction("Number", *interpreter().global_object().function_prototype())
 {
     put_native_function("isFinite", is_finite, 1);
+    put_native_function("isNaN", is_nan, 1);
     put_native_function("isSafeInteger", is_safe_integer, 1);
 
     put("prototype", interpreter().global_object().number_prototype());
@@ -79,6 +80,11 @@ Value NumberConstructor::is_finite(Interpreter& interpreter)
     return Value(interpreter.argument(0).is_finite_number());
 }
 
+Value NumberConstructor::is_nan(Interpreter& interpreter)
+{
+    return Value(interpreter.argument(0).is_nan());
+}
+
 Value NumberConstructor::is_safe_integer(Interpreter& interpreter)
 {
     if (!interpreter.argument(0).is_number())