[Effen] Remove '_isInCheckedMode' flag and use an assert() instead, since presumably that will more…

sky/framework/fn.dart

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 library fn;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:sky' as sky;
 import 'reflect.dart' as reflect;
 
 final sky.Tracing _tracing = sky.window.tracing;
 
-bool _initIsInCheckedMode() {
-  String testFn(i) { double d = i; return d.toString(); }
-  try {
-    testFn('not a double');
-  } catch (ex) {
-    return true;
-  }
-  return false;
-}
-
-final bool _isInCheckedMode = _initIsInCheckedMode();
 final bool _shouldLogRenderDuration = false;
 final bool _shouldTrace = false;
 
 class Style {
   final String _className;
   static final Map<String, Style> _cache = new HashMap<String, Style>();
 
   static int _nextStyleId = 1;
 
   static String _getNextClassName() { return "style${_nextStyleId++}"; }
@@ skipping 354 matching lines @@
   String _class;
 
   WrapperNode({
     Object key,
     List<UINode> children,
     this.style,
     this.inlineStyle
   }) : this.children = children == null ? _emptyList : children,
        super(key:key) {
 
-    if (_isInCheckedMode) {
-      _debugReportDuplicateIds();
-    }
+    assert(!_debugHasDuplicateIds());
   }
 
   void _remove() {
     super._remove();
     if (children != null) {
       for (var child in children) {
         _removeChild(child);
       }
     }
   }
 
-  void _debugReportDuplicateIds() {
+  bool _debugHasDuplicateIds() {
     var idSet = new HashSet<String>();
     for (var child in children) {
       if (child is Text) {
         continue; // Text nodes all have the same key and are never reordered.
       }
 
       if (!idSet.add(child._key)) {
         throw '''If multiple (non-Text) nodes of the same type exist as children
                  of another node, they must have unique keys.''';
       }
     }
+    return false;
   }
 
   void _ensureClass() {
     if (_class == null) {
       List<Style> styles = new List<Style>();
       if (style != null) {
         styles.add(style);
       }
 
       UINode parent = _parent;
@@ skipping 458 matching lines @@
 
 abstract class App extends Component {
   sky.Node _host;
 
   App() : super(stateful: true) {
     _host = sky.document.createElement('div');
     sky.document.appendChild(_host);
     _scheduleComponentForRender(this);
   }
 }