Ensure that exception message is printed.

frog/frogsh

Index: frog/frogsh
diff --git a/frog/frogsh b/frog/frogsh
index eb651dd7166be6fadf795c6e691c42ebf1f7fe42..721dd3b9c9c7929b67a286a863ed607905f22d25 100755
--- a/frog/frogsh
+++ b/frog/frogsh
@@ -73,42 +73,58 @@ Function.prototype.$genStub = function(argsLength, names) {
 // Translate a JavaScript exception to a Dart exception
 // TODO(jmesserly): cross browser support. This is Chrome specific.
 function $toDartException(e) {
-  var res = e;
+  function attachStack(dartEx) {
+    // TODO(jmesserly): setting the stack property is not a long term solution.
+    var stack = e.stack;
+    // The stack contains the error message, and the stack is all that is
+    // printed (the exception's toString() is never called).  Attempt to replace
+    // the JS message (e.g. TypeError) with the Dart exception's toString().
+    if (typeof stack == 'string') {
+      try {  // toString is in a try-catch due to Issue 470.
+        var message = dartEx.toString();
+        if (/^(Type|Range)Error:/.test(stack)) {
+          // Remove JS message.
+          stack = stack.substring(stack.indexOf('\n') + 1);
+        }
+        stack = message + '\n' + stack;
+      } catch(_) {
+        stack = '' + dartEx.constructor.name + ': (corrupt)\n' + stack;
+      }
+    }
+    dartEx.stack = stack;
+    return dartEx;
+  }
+
   if (e instanceof TypeError) {
     switch(e.type) {
       case 'property_not_function':
       case 'called_non_callable':
         if (e.arguments[0] == null) {
-          res = new NullPointerException();
+          return attachStack(new NullPointerException());
         } else {
-          res = new ObjectNotClosureException();
+          return attachStack(new ObjectNotClosureException());
         }
         break;
       case 'non_object_property_call':
       case 'non_object_property_load':
-        res = new NullPointerException();
+        return attachStack(new NullPointerException());
         break;
       case 'undefined_method':
         if (e.arguments[0] == 'call' || e.arguments[0] == 'apply') {
-          res = new ObjectNotClosureException();
+          return attachStack(new ObjectNotClosureException());
         } else {
           // TODO(jmesserly): can this ever happen?
-          res = new NoSuchMethodException('', e.arguments[0], []);
+          // sra: Yes.
+          return attachStack(new NoSuchMethodException('', e.arguments[0], []));
         }
         break;
     }
   } else if (e instanceof RangeError) {
     if (e.message.indexOf('call stack') >= 0) {
-      res = new StackOverflowException();
+      return attachStack(new StackOverflowException());
     }
   }
-  if (res) {
-    // TODO(jmesserly): setting the stack property is not a long term solution.
-    // Also it causes the exception to print as if it were a JS TypeError or
-    // RangeError, instead of using the proper toString.
-    res.stack = e.stack;
-  }
-  return res;
+  return e;
 }
 function $notnull_bool(test) {
   return (test === true || test === false) ? test : test.is$bool(); // TypeError
@@ -12154,7 +12170,7 @@ CoreJs.prototype.generate = function(w) {
     w.writeln("function $stackTraceOf(e) {\n  // TODO(jmesserly): we shouldn't be relying on the e.stack property.\n  // Need to mangle it.\n  return  (e && e.stack) ? e.stack : null;\n}");
   }
   if ($notnull_bool(this.useToDartException)) {
-    w.writeln("// Translate a JavaScript exception to a Dart exception\n// TODO(jmesserly): cross browser support. This is Chrome specific.\nfunction $toDartException(e) {\n  var res = e;\n  if (e instanceof TypeError) {\n    switch(e.type) {\n      case 'property_not_function':\n      case 'called_non_callable':\n        if (e.arguments[0] == null) {\n          res = new NullPointerException();\n        } else {\n          res = new ObjectNotClosureException();\n        }\n        break;\n      case 'non_object_property_call':\n      case 'non_object_property_load':\n        res = new NullPointerException();\n        break;\n      case 'undefined_method':\n        if (e.arguments[0] == 'call' || e.arguments[0] == 'apply') {\n          res = new ObjectNotClosureException();\n        } else {\n          // TODO(jmesserly): can this ever happen?\n          res = new NoSuchMethodException('', e.arguments[0], []);\n        }\n        break;\n    }\n  } else if (e instanceof RangeError) {\n    if (e.message.indexOf('call stack') >= 0) {\n      res = new StackOverflowException();\n    }\n  }\n  if (res) {\n    // TODO(jmesserly): setting the stack property is not a long term solution.\n    // Also it causes the exception to print as if it were a JS TypeError or\n    // RangeError, instead of using the proper toString.\n    res.stack = e.stack;\n  }\n  return res;\n}");
+    w.writeln("// Translate a JavaScript exception to a Dart exception\n// TODO(jmesserly): cross browser support. This is Chrome specific.\nfunction $toDartException(e) {\n  function attachStack(dartEx) {\n    // TODO(jmesserly): setting the stack property is not a long term solution.\n    var stack = e.stack;\n    // The stack contains the error message, and the stack is all that is\n    // printed (the exception's toString() is never called).  Attempt to replace\n    // the JS message (e.g. TypeError) with the Dart exception's toString().\n    if (typeof stack == 'string') {\n      try {  // toString is in a try-catch due to Issue 470.\n        var message = dartEx.toString();\n        if (/^(Type|Range)Error:/.test(stack)) {\n          // Remove JS message.\n          stack = stack.substring(stack.indexOf('\\n') + 1);\n        }\n        stack = message + '\\n' + stack;\n      } catch(_) {\n        stack = '' + dartEx.constructor.name + ': (corrupt)\\n' + stack;\n      }\n    }\n    dartEx.stack = stack;\n    return dartEx;\n  }\n\n  if (e instanceof TypeError) {\n    switch(e.type) {\n      case 'property_not_function':\n      case 'called_non_callable':\n        if (e.arguments[0] == null) {\n          return attachStack(new NullPointerException());\n        } else {\n          return attachStack(new ObjectNotClosureException());\n        }\n        break;\n      case 'non_object_property_call':\n      case 'non_object_property_load':\n        return attachStack(new NullPointerException());\n        break;\n      case 'undefined_method':\n        if (e.arguments[0] == 'call' || e.arguments[0] == 'apply') {\n          return attachStack(new ObjectNotClosureException());\n        } else {\n          // TODO(jmesserly): can this ever happen?\n          // sra: Yes.\n          return attachStack(new NoSuchMethodException('', e.arguments[0], []));\n        }\n        break;\n    }\n  } else if (e instanceof RangeError) {\n    if (e.message.indexOf('call stack') >= 0) {\n      return attachStack(new StackOverflowException());\n    }\n  }\n  return e;\n}");
   }
   if ($notnull_bool(this.useNotNullBool)) {
     this.useThrow = true;