LibJS: Implement Number.isNaN()

Like the global isNaN() without the number coercion.

3 files changed, 8 insertions, 2 deletions

diff --git a/Libraries/LibJS/Runtime/GlobalObject.cpp b/Libraries/LibJS/Runtime/GlobalObject.cpp
index 0612da4669..6e289b7f56 100644
--- a/Libraries/LibJS/Runtime/GlobalObject.cpp
+++ b/Libraries/LibJS/Runtime/GlobalObject.cpp
@@ -138,8 +138,7 @@ Value GlobalObject::gc(Interpreter& interpreter)
 
 Value GlobalObject::is_nan(Interpreter& interpreter)
 {
-    auto value = interpreter.argument(0).to_number();
-    return Value(value.is_nan());
+    return Value(interpreter.argument(0).to_number().is_nan());
 }
 
 Value GlobalObject::is_finite(Interpreter& interpreter)
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())
diff --git a/Libraries/LibJS/Runtime/NumberConstructor.h b/Libraries/LibJS/Runtime/NumberConstructor.h
index 23557009b0..ba22130530 100644
--- a/Libraries/LibJS/Runtime/NumberConstructor.h
+++ b/Libraries/LibJS/Runtime/NumberConstructor.h
@@ -43,6 +43,7 @@ private:
     virtual const char* class_name() const override { return "NumberConstructor"; }
 
     static Value is_finite(Interpreter&);
+    static Value is_nan(Interpreter&);
     static Value is_safe_integer(Interpreter&);
 };