- Improve the message for NoSuchMethodErrors that are

runtime/lib/errors_patch.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.
 
 patch class Error {
   /* patch */ static String _objectToString(Object object) {
     return Object._toString(object);
   }
 }
 
 patch class NoSuchMethodError {
   // The compiler emits a call to _throwNew when it cannot resolve a static
   // method at compile time. The receiver is actually the literal class of the
   // unresolved method.
   static void _throwNew(Object receiver,
                         String memberName,
+                        int invocation_type,
                         List arguments,
                         List argumentNames,
                         List existingArgumentNames) {
     int numNamedArguments = argumentNames == null ? 0 : argumentNames.length;
     int numPositionalArguments = arguments == null ? 0 : arguments.length;
     numPositionalArguments -= numNamedArguments;
     List positionalArguments;
     if (numPositionalArguments == 0) {
       positionalArguments = [];
     } else {
       positionalArguments = arguments.getRange(0, numPositionalArguments);
     }
     Map<String, dynamic> namedArguments = new Map<String, dynamic>();
     for (int i = 0; i < numNamedArguments; i++) {
       var arg_value = arguments[numPositionalArguments + i];
       namedArguments[argumentNames[i]] = arg_value;
     }
-    throw new NoSuchMethodError(receiver,
+    throw new NoSuchMethodError._withType(receiver,
                                 memberName,
+                                invocation_type,
                                 positionalArguments,
                                 namedArguments,
                                 existingArgumentNames);
   }
 
+  final int _invocation_type;
+
   const NoSuchMethodError(Object this._receiver,
                           String this._memberName,
                           List this._arguments,
                           Map<String,dynamic> this._namedArguments,
                           [List existingArgumentNames = null])
+      : this._existingArgumentNames = existingArgumentNames,
+        this._invocation_type = 0;

[regis, 2013/02/21 00:48:18]

What is 0?

[Ivan Posva, 2013/02/21 18:51:40]

 Changed to -1 to mark invalid/unknown invocation types, which will not print a
developer message at all.

+
+  const NoSuchMethodError._withType(Object this._receiver,
+                                  String this._memberName,

[regis, 2013/02/21 00:48:18]

indentation

[Ivan Posva, 2013/02/21 18:51:40]

Done.

+                                  this._invocation_type,
+                                  List this._arguments,
+                                  Map<String,dynamic> this._namedArguments,
+                                  [List existingArgumentNames = null])
       : this._existingArgumentNames = existingArgumentNames;
 
+
+  String _developerMessage() {
+    var type = _invocation_type & _InvocationMirror._TYPE_MASK;
+    var level = (_invocation_type >> _InvocationMirror._CALL_SHIFT) &
+         _InvocationMirror._CALL_MASK;
+    var type_str =
+        (const ["method", "getter", "setter", "getter or setter"])[type];
+    var msg;
+    switch (level) {
+      case _InvocationMirror._DYNAMIC: {
+        if (_receiver == null) {
+          msg = "The null object does not support $type_str '$_memberName'.";
+        } else {
+          msg = "No $type_str '$_memberName' declared in class "
+              "'${_receiver.runtimeType}'.";
+        }
+        break;
+      }
+      case _InvocationMirror._STATIC: {
+        msg = "No static $type_str '$_memberName' declared in class "
+            "'$_receiver'.";
+        break;
+      }
+      case _InvocationMirror._CONSTRUCTOR: {
+        msg = "No constructor '$_memberName' declared in class '$_receiver'.";
+        break;
+      }
+      case _InvocationMirror._TOP_LEVEL: {
+        msg = "No top-level $type_str '$_memberName' declared.";
+        break;
+      }
+    }
+    return msg;
+  }
+
   /* patch */ String toString() {
     StringBuffer actual_buf = new StringBuffer();
     int i = 0;
     if (_arguments != null) {
       for (; i < _arguments.length; i++) {
         if (i > 0) {
           actual_buf.add(", ");
         }
         actual_buf.add(Error.safeToString(_arguments[i]));
       }
     }
     if (_namedArguments != null) {
       _namedArguments.forEach((String key, var value) {
         if (i > 0) {
           actual_buf.add(", ");
         }
         actual_buf.add(key);
         actual_buf.add(": ");
         actual_buf.add(Error.safeToString(value));
         i++;
       });
     }
-    StringBuffer msg_buf = new StringBuffer();
+    StringBuffer msg_buf = new StringBuffer(_developerMessage());
+    msg_buf.add("\n\n");
     if (_existingArgumentNames == null) {
       msg_buf.add(
           "NoSuchMethodError : method not found: '$_memberName'\n"
           "Receiver: ${Error.safeToString(_receiver)}\n"
           "Arguments: [$actual_buf]");
     } else {
       String actualParameters = actual_buf.toString();
       StringBuffer formal_buf = new StringBuffer();
       for (int i = 0; i < _existingArgumentNames.length; i++) {
         if (i > 0) {
           formal_buf.add(", ");
         }
         formal_buf.add(_existingArgumentNames[i]);
       }
       String formalParameters = formal_buf.toString();
       msg_buf.add( 
           "NoSuchMethodError: incorrect number of arguments passed to "
           "method named '$_memberName'\n"
           "Receiver: ${Error.safeToString(_receiver)}\n"
           "Tried calling: $_memberName($actualParameters)\n"
           "Found: $_memberName($formalParameters)");
     }
     return msg_buf.toString();
   }
 }