feat: javascript helpers extension

fix #881

Author: alandefreitas

src/lib/Support/JavaScript.cpp

@@ -301,7 +301,19 @@ dom::Value Value::getDom() const
 
 std::string Value::getString() const { return std::string(getDom().getString()); }
 bool Value::getBool() const { return getDom().getBool(); }
-std::int64_t Value::getInteger() const { return getDom().getInteger(); }
+std::int64_t Value::getInteger() const
+{
+    auto lock = lockContext(impl_);
+    double d = jerry_value_as_number(to_js(val_));
+
+    // Mirror legacy behavior: convert any JS number to an integer by
+    // truncating toward zero instead of requiring an integral DOM value.
+    if (d >= (double)std::numeric_limits<std::int64_t>::max())
+        return std::numeric_limits<std::int64_t>::max();
+    if (d <= (double)std::numeric_limits<std::int64_t>::min())
+        return std::numeric_limits<std::int64_t>::min();
+    return static_cast<std::int64_t>(d);
+}
 double Value::getDouble() const
 {
     auto lock = lockContext(impl_);