feat(compiler): Mapped attributes are snake-cased correctly.

Author: jbdeboer

lib/angular.dart

@@ -37,6 +37,7 @@ part 'node_cursor.dart';
 part 'parser.dart';
 part 'scope.dart';
 part 'selector.dart';
+part 'string_utilities.dart';
 
 ASSERT(condition) {
   if (!condition) {

lib/block.dart

@@ -318,7 +318,7 @@ class ComponentFactory {
 
   createAttributeMapping(Scope parentScope, Scope shadowScope, Parser parser) {
     directive.$map.forEach((attrName, mapping) {
-      var attrValue = element.attributes[attrName];
+      var attrValue = element.attributes[snakeCase(attrName, '-')];
       if (attrValue == null) attrValue = '';
       if (mapping == '@') {
         shadowScope[attrName] = attrValue;

lib/string_utilities.dart

@@ -0,0 +1,7 @@
+part of angular;
+
+var SNAKE_CASE_REGEXP = new RegExp("[A-Z]");
+
+snakeCase(String name, [separator = '_']) =>
+  name.replaceAllMapped(SNAKE_CASE_REGEXP, (Match match) =>
+    (match.start != 0 ? separator : '') + match.group(0).toLowerCase());

test/compiler_spec.dart

@@ -391,6 +391,7 @@ main() {
     describe('components', () {
       beforeEach(module((AngularModule module) {
         module.directive(SimpleComponent);
+        module.directive(CamelCaseMapComponent);
         module.directive(IoComponent);
         module.directive(ParentExpressionComponent);
         module.directive(PublishMeComponent);
@@ -412,7 +413,7 @@ main() {
       it('should create a component that can access parent scope', inject(() {
         $rootScope.fromParent = "should not be used";
         $rootScope.val = "poof";
-        var element = $('<parent-expression fromParent=val></parent-expression>');
+        var element = $('<parent-expression from-parent=val></parent-expression>');
 
         $compile(element)(injector, element);
 
@@ -455,6 +456,14 @@ main() {
         expect($rootScope.done).toEqual(true);
       }));
 
+      it('should expose mapped attributes as camel case', inject(() {
+        var element = $('<camel-case-map camel-case=6></camel-case-map>');
+        $compile(element)(injector, element);
+        $rootScope.$apply();
+        var componentScope = $rootScope.camelCase;
+        expect(componentScope.camelCase).toEqual('6');
+      }));
+
       it('should throw an exception if required directive is missing', inject((Compiler $compile, Scope $rootScope, Injector injector) {
         expect(() {
           var element = $('<tab local><pane></pane><pane local></pane></tab>');
@@ -510,6 +519,13 @@ class IoComponent {
   }
 }
 
+class CamelCaseMapComponent {
+  static Map $map = {"camelCase": "@"};
+  CamelCaseMapComponent(Scope scope) {
+    scope.$root.camelCase = scope;
+  }
+}
+
 class ParentExpressionComponent {
   static String $template = '<div>inside {{fromParent()}}</div>';
   static Map $map = {"fromParent": "&"};

test/string_utilities_spec.dart

@@ -0,0 +1,16 @@
+import "_specs.dart";
+
+main() {
+   describe('snakeCase', (){
+    it('should convert to snake_case', () {
+      expect(snakeCase('ABC')).toEqual('a_b_c');
+      expect(snakeCase('alanBobCharles')).toEqual('alan_bob_charles');
+    });
+
+
+    it('should allow seperator to be overridden', () {
+      expect(snakeCase('ABC', '&')).toEqual('a&b&c');
+      expect(snakeCase('alanBobCharles', '&')).toEqual('alan&bob&charles');
+    });
+  });
+}