About half a year ago. It turned 1500 lines of Dart into ~10000 lines of Javascript. That might not be that much to handle for a webview but it was quite hard to debug. I used it as a UserScript in WKWebView so I couldn't use DartEditor. In comparison, the haxe code, which looked very similar to the Dart code, was compiled into 1400 lines of pretty readable Javascript.
