fix(html_extractor): correct handling of camelCased attributes

fix dart-archive#1047
closes dart-archive#1301

Author: vicb

lib/tools/common.dart

@@ -1,17 +1,18 @@
 library angular.tools.common;
 
+import 'dart:collection';
+
 class DirectiveInfo {
   String selector;
   String template;
   List<String> expressionAttrs = <String>[];
   List<String> expressions = <String>[];
   DirectiveInfo([this.selector, this.expressionAttrs, this.expressions]) {
-    if (expressionAttrs == null) {
-      expressionAttrs = <String>[];
-    }
-    if (expressions == null) {
-      expressions = <String>[];
-    }
+    expressionAttrs = expressionAttrs == null ?
+        new _AttributeList() :
+        new _AttributeList()..addAll(expressionAttrs);
+
+    if (expressions == null) expressions = <String>[];
   }
 }
 
@@ -42,3 +43,29 @@ class DirectiveMetadata {
   }
 }
 
+/**
+ * Extends list to always returned lowercase attribute name:
+ *
+ *   var l = new _AttributeList();
+ *   l.add('fooBar');
+ *   print(l[0]); // "foobar"
+ *
+ * It helps working with html5lib `Node` class which also lowercase attribute names.
+ *
+ * Note: attribute names are case-insensitive in HTML.
+ */
+class _AttributeList extends ListBase<String> {
+  final List<String> _attributes = [];
+
+  void set length(int len) {
+    _attributes.length = len;
+  }
+
+  int get length => _attributes.length;
+
+  String operator [](int index) => _attributes[index].toLowerCase();
+
+  void operator []=(int index, String value) {
+    _attributes[index] = value;
+  }
+}

lib/tools/html_extractor.dart

@@ -49,14 +49,12 @@ class HtmlExpressionExtractor {
         });
       }
       if (matchesNode(node, r'[ng-repeat]')) {
-        var expr = _NG_REPEAT_SYNTAX.
-            firstMatch(node.attributes['ng-repeat']).group(2);
+        var expr = _NG_REPEAT_SYNTAX.firstMatch(node.attributes['ng-repeat']).group(2);
         expressions.add(expr);
       }
 
       for (DirectiveInfo directiveInfo in directiveInfos) {
-        if (directiveInfo.selector != null &&
-            matchesNode(node, directiveInfo.selector)) {
+        if (directiveInfo.selector != null && matchesNode(node, directiveInfo.selector)) {
           directiveInfo.expressionAttrs.forEach((attr) {
             if (node.attributes[attr] != null && attr != 'ng-repeat') {
               expressions.add(node.attributes[attr]);

test/tools/html_extractor_spec.dart

@@ -61,18 +61,23 @@ void main() {
     });
 
     it('should extract expressions from expression attributes', () {
-      var ioService = new MockIoService({
-          'foo.html': r'''
-        <foo bar="ctrl.baz"></foo>
-      '''
-      });
+      var ioService = new MockIoService({'foo.html': r'<foo bar="ctrl.baz"></foo>'});
 
       var extractor = new HtmlExpressionExtractor([
           new DirectiveInfo('foo', ['bar'])
       ]);
       extractor.crawl('/', ioService);
-      expect(extractor.expressions.toList()..sort(),
-      equals(['ctrl.baz']));
+      expect(extractor.expressions.toList()).toEqual(['ctrl.baz']);
+    });
+
+    it('should extract expressions from expression attributes for camelCased attributes', () {
+      var ioService = new MockIoService({'foo.html': r'<foo fooBar="ctrl.baz"></foo>'});
+
+      var extractor = new HtmlExpressionExtractor([
+          new DirectiveInfo('foo', ['fooBar'])
+      ]);
+      extractor.crawl('/', ioService);
+      expect(extractor.expressions.toList()).toEqual(['ctrl.baz']);
     });
 
     it('should ignore ng-repeat while extracting attribute expressions', () {