fix(change_detect): Handle '$' in change detector strings

In Dart, '$' indicates the beginning of an interpolation.
- Escapes '$' in strings when generating change detector classes.
- Adds a unit test to cover this case.

Author: Tim Blasi

modules/angular2/src/transform/template_compiler/change_detector_codegen.dart

@@ -142,7 +142,7 @@ class _CodegenState {
         $_changeDetectorTypeName(
             this.$_DISPATCHER_ACCESSOR,
             this.$_PROTOS_ACCESSOR,
-            this.$_DIRECTIVES_ACCESSOR) : super(${JSON.encode(_changeDetectorDefId)});
+            this.$_DIRECTIVES_ACCESSOR) : super(${_encodeValue(_changeDetectorDefId)});
 
         void detectChangesInRecords(throwOnChange) {
           if (!hydrated()) {
@@ -383,7 +383,7 @@ class _CodegenState {
         break;
 
       case RecordType.CONST:
-        rhs = JSON.encode(r.funcOrValue);
+        rhs = _encodeValue(r.funcOrValue);
         break;
 
       case RecordType.PROPERTY:
@@ -435,9 +435,9 @@ class _CodegenState {
     for (var i = 0; i < r.args.length; ++i) {
       var name = _localNames[r.args[i]];
       res.write(
-          '${JSON.encode(r.fixedArgs[i])} "\$\{$name == null ? "" : $name\}" ');
+          '${_encodeValue(r.fixedArgs[i])} "\$\{$name == null ? "" : $name\}" ');
     }
-    res.write(JSON.encode(r.fixedArgs[r.args.length]));
+    res.write(_encodeValue(r.fixedArgs[r.args.length]));
     return '$res';
   }
 
@@ -523,6 +523,9 @@ class _CodegenState {
       }
     ''';
   }
+
+  String _encodeValue(funcOrValue) =>
+      JSON.encode(funcOrValue).replaceAll(r'$', r'\$');
 }
 
 const PROTO_CHANGE_DETECTOR_FACTORY_METHOD = 'newProtoChangeDetector';

modules/angular2/test/change_detection/change_detector_config.ts

@@ -263,6 +263,7 @@ class _DirectiveUpdating {
  * equivalent to their ids.
  */
 var _availableDefinitions = [
+  '"$"',
   '10',
   '"str"',
   '"a\n\nb"',

modules/angular2/test/change_detection/change_detector_spec.ts

@@ -302,6 +302,9 @@ export function main() {
         expect(val.dispatcher.log).toEqual(['propName=BvalueA']);
       });
 
+      it('should escape values in literals that indicate interpolation',
+         () => { expect(_bindSimpleValue('"$"')).toEqual(['propName=$']); });
+
       describe('pure functions', () => {
         it('should preserve memoized result', () => {
           var person = new Person('bob');

modules/angular2/test/change_detection/generator/gen_change_detectors.dart

@@ -21,7 +21,7 @@ void main(List<String> args) {
     if (i > 0) {
       buf.write(',');
     }
-    buf.write(" '''${allDefs[i].cdDef.id}''': "
+    buf.write(" '''${_escape(allDefs[i].cdDef.id)}''': "
         "$className.$PROTO_CHANGE_DETECTOR_FACTORY_METHOD");
   }
   buf.write('};');
@@ -37,4 +37,6 @@ void main(List<String> args) {
   '''));
 }
 
+String _escape(String id) => id.replaceAll(r'$', r'\$');
+
 const _MAP_NAME = '_idToProtoMap';