Debugger break on TypeError, AssertionError

tools/ddbg.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // Simple interactive debugger shell that connects to the Dart VM's debugger
 // connection port.
 
 #import("dart:io");
 #import("dart:json");
 
@@ skipping 116 matching lines @@
   } else if (command == "q") {
     quitShell();
   } else if (command == "h") {
     printHelp();
   } else {
     print("command '$command' not understood, try h for help");
   }
 }
 
 
+String remoteValue(value) {
+  var kind = value["kind"];
+  var text = value["text"];
+  var id = value["objectId"];
+  if (kind == "string") {
+    return "'$text'";
+  } else if (kind == "object") {
+    return "(obj id: $id) = $text";
+  } else {
+    return "$text";
+  }
+}
+
+
 printNamedObject(obj) {
   var name = obj["name"];
   var value = obj["value"];
-  var kind = value["kind"];
-  var text = value["text"];
-  var id = value["objectId"];
-  if (kind == "string") {
-    print("  $name = '$text'");
-  } else if (kind == "object") {
-    print("  $name (id:$id) = $text");
-  } else {
-    print("  $name = $text");
-  }
+  print("  $name = ${remoteValue(value)}");
 }
 
 
 handleGetObjPropsResponse(response) {
   Map props = response["result"];
   int class_id = props["classId"];
   if (class_id == -1) {
     print("  null");
     return;
   }
@@ skipping 109 matching lines @@
 
 void printStackTrace(List frames) {
   for (int i = 0; i < frames.length; i++) {
     printStackFrame(i, frames[i]);
   }
 }
 
 
 void handlePausedEvent(msg) {
   assert(msg["params"] != null);
+  var reason = msg["params"]["reason"];
   stackTrace = msg["params"]["callFrames"];
   assert(stackTrace != null);
   assert(stackTrace.length >= 1);
   curFrame = stackTrace[0];
-  print("VM paused, stack trace:");
+  if (reason == "breakpoint") {
+    print("VM paused on breakpoint");
+  } else {
+    assert(reason == "exception");
+    var excObj = msg["params"]["exception"];
+    print("VM paused on exception");
+    print(remoteValue(excObj));
+  }
+  print("Stack trace:");
   printStackTrace(stackTrace);
 }
 
 
 void processVmMessage(String json) {
   var msg = JSON.parse(json);
   if (msg == null) {
     return;
   }
   var event = msg["event"];
@@ skipping 69 matching lines @@
   };
   vmInStream.onError = (err) {
     print("Error in debug connection: $err");
     quitShell();
   };
   vmInStream.onClosed = () {
     print("VM debugger connection closed");
     quitShell();
   };
 }