LibJS: Add Date.prototype.toGMTString()

Userland/Libraries/LibJS/Runtime/CommonPropertyNames.h

@@ -220,6 +220,7 @@ namespace JS {
     P(tanh)                                  \
     P(test)                                  \
     P(toDateString)                          \
+    P(toGMTString)                           \
     P(toISOString)                           \
     P(toJSON)                                \
     P(toLocaleDateString)                    \

Userland/Libraries/LibJS/Runtime/Date.cpp

@@ -91,6 +91,13 @@ int Date::utc_seconds() const
     return to_utc_tm().tm_sec;
 }
 
+String Date::gmt_date_string() const
+{
+    // Mon, 18 Dec 1995 17:28:35 GMT
+    // FIXME: Note that we're totally cheating with the timezone part here..
+    return datetime().to_string("%a, %e %b %Y %T GMT");
+}
+
 String Date::iso_date_string() const
 {
     auto tm = to_utc_tm();

Userland/Libraries/LibJS/Runtime/Date.h

@@ -71,6 +71,7 @@ public:
         return String::formatted("{} {}", date_string(), time_string());
     }
 
+    String gmt_date_string() const;
     String iso_date_string() const;
 
     // FIXME: One day, implement real locale support. Until then, everyone gets what the Clock MenuApplet displays.

Userland/Libraries/LibJS/Runtime/DatePrototype.cpp

@@ -76,6 +76,7 @@ void DatePrototype::initialize(GlobalObject& global_object)
     define_native_function(vm.names.getUTCMonth, get_utc_month, 0, attr);
     define_native_function(vm.names.getUTCSeconds, get_utc_seconds, 0, attr);
     define_native_function(vm.names.toDateString, to_date_string, 0, attr);
+    define_native_function(vm.names.toGMTString, to_gmt_string, 0, attr);
     define_native_function(vm.names.toISOString, to_iso_string, 0, attr);
     define_native_function(vm.names.toLocaleDateString, to_locale_date_string, 0, attr);
     define_native_function(vm.names.toLocaleString, to_locale_string, 0, attr);
@@ -256,6 +257,15 @@ JS_DEFINE_NATIVE_FUNCTION(DatePrototype::to_date_string)
     return js_string(vm, move(string));
 }
 
+JS_DEFINE_NATIVE_FUNCTION(DatePrototype::to_gmt_string)
+{
+    auto* this_object = typed_this(vm, global_object);
+    if (!this_object)
+        return {};
+    auto string = this_object->gmt_date_string();
+    return js_string(vm, move(string));
+}
+
 JS_DEFINE_NATIVE_FUNCTION(DatePrototype::to_iso_string)
 {
     auto* this_object = typed_this(vm, global_object);

Userland/Libraries/LibJS/Runtime/DatePrototype.h

@@ -58,6 +58,7 @@ private:
     JS_DECLARE_NATIVE_FUNCTION(get_utc_month);
     JS_DECLARE_NATIVE_FUNCTION(get_utc_seconds);
     JS_DECLARE_NATIVE_FUNCTION(to_date_string);
+    JS_DECLARE_NATIVE_FUNCTION(to_gmt_string);
     JS_DECLARE_NATIVE_FUNCTION(to_iso_string);
     JS_DECLARE_NATIVE_FUNCTION(to_locale_date_string);
     JS_DECLARE_NATIVE_FUNCTION(to_locale_string);