LibJS: Implement Date's string constructor

... by calling Date.parse().

With this, dates on http://45.33.8.238/ and
http://45.33.8.238/linux/summary.html are correctly converted to local
time :^)

2 files changed, 12 insertions, 11 deletions

diff --git a/Libraries/LibJS/Runtime/DateConstructor.cpp b/Libraries/LibJS/Runtime/DateConstructor.cpp
index 1366a919bd..ec91f36897 100644
--- a/Libraries/LibJS/Runtime/DateConstructor.cpp
+++ b/Libraries/LibJS/Runtime/DateConstructor.cpp
@@ -173,21 +173,16 @@ Value DateConstructor::construct(Interpreter& interpreter, Function&)
         auto milliseconds = static_cast<u16>(tv.tv_usec / 1000);
         return Date::create(global_object(), datetime, milliseconds);
     }
-    if (interpreter.argument_count() == 1 && interpreter.argument(0).is_string()) {
-        // FIXME: Parse simplified ISO8601-like string, like Date.parse() will do.
-        struct timeval tv;
-        gettimeofday(&tv, nullptr);
-        auto datetime = Core::DateTime::now();
-        auto milliseconds = static_cast<u16>(tv.tv_usec / 1000);
-        return Date::create(global_object(), datetime, milliseconds);
-    }
     if (interpreter.argument_count() == 1) {
+        auto value = interpreter.argument(0);
+        if (value.is_string())
+            value = parse_simplified_iso8601(value.as_string().string());
         // A timestamp since the epoch, in UTC.
         // FIXME: Date() probably should use a double as internal representation, so that NaN arguments and larger offsets are handled correctly.
         // FIXME: DateTime::from_timestamp() seems to not support negative offsets.
-        double value = interpreter.argument(0).to_double(interpreter);
-        auto datetime = Core::DateTime::from_timestamp(static_cast<time_t>(value / 1000));
-        auto milliseconds = static_cast<u16>(fmod(value, 1000));
+        double value_as_double = value.to_double(interpreter);
+        auto datetime = Core::DateTime::from_timestamp(static_cast<time_t>(value_as_double / 1000));
+        auto milliseconds = static_cast<u16>(fmod(value_as_double, 1000));
         return Date::create(global_object(), datetime, milliseconds);
     }
     // A date/time in components, in local time.
diff --git a/Libraries/LibJS/Tests/builtins/Date/Date.js b/Libraries/LibJS/Tests/builtins/Date/Date.js
index c7a2669675..80551e638b 100644
--- a/Libraries/LibJS/Tests/builtins/Date/Date.js
+++ b/Libraries/LibJS/Tests/builtins/Date/Date.js
@@ -4,6 +4,12 @@ test("basic functionality", () => {
     expect(Date.prototype).not.toHaveProperty("length");
 });
 
+test("string constructor", () => {
+    // The string constructor is the same as calling the timestamp constructor with the result of Date.parse(arguments).
+    // Since that has exhaustive tests in Date.parse.js, just do some light smoke testing here.
+    expect(new Date("2017-09-07T21:08:59.001Z").toISOString()).toBe("2017-09-07T21:08:59.001Z");
+});
+
 test("timestamp constructor", () => {
     // The timestamp constructor takes a timestamp in milliseconds since the start of the epoch, in UTC.