Update the Angular/DI tests to latest from github.

third_party/pkg/angular/lib/change_detection/ast.dart

+part of angular.watch_group;
+
+
+/**
+ * RULES:
+ *  - ASTs are reusable. Don't store scope/instance refs there
+ *  - Parent knows about children, not the other way around.
+ */
+abstract class AST {
+  static final String _CONTEXT = '#';
+  final String expression;
+  AST(expression)
+      : expression = expression.startsWith('#.')
+          ? expression.substring(2)
+          : expression
+  {
+    assert(expression!=null);
+  }
+  WatchRecord<_Handler> setupWatch(WatchGroup watchGroup);
+  String toString() => expression;
+}
+
+/**
+ * SYNTAX: _context_
+ *
+ * This represent the initial _context_ for evaluation.
+ */
+class ContextReferenceAST extends AST {
+  ContextReferenceAST(): super(AST._CONTEXT);
+  WatchRecord<_Handler> setupWatch(WatchGroup watchGroup) =>
+      new _ConstantWatchRecord(watchGroup, expression, watchGroup.context);
+}
+
+/**
+ * SYNTAX: _context_
+ *
+ * This represent the initial _context_ for evaluation.
+ */
+class ConstantAST extends AST {
+  final constant;
+
+  ConstantAST(constant, [String expression])
+      : constant = constant,
+        super(expression == null
+            ? constant is String ? '"$constant"' : '$constant'
+            : expression);
+
+  WatchRecord<_Handler> setupWatch(WatchGroup watchGroup) =>
+      new _ConstantWatchRecord(watchGroup, expression, constant);
+}
+
+/**
+ * SYNTAX: lhs.name.
+ *
+ * This is the '.' dot operator.
+ */
+class FieldReadAST extends AST {
+  AST lhs;
+  final String name;
+
+  FieldReadAST(lhs, name)
+      : lhs = lhs,
+        name = name,
+        super('$lhs.$name');
+
+  WatchRecord<_Handler> setupWatch(WatchGroup watchGroup) =>
+      watchGroup.addFieldWatch(lhs, name, expression);
+}
+
+/**
+ * SYNTAX: fn(arg0, arg1, ...)
+ *
+ * Invoke a pure function. Pure means that the function has no state, and
+ * therefore it needs to be re-computed only if its args change.
+ */
+class PureFunctionAST extends AST {
+  final String name;
+  final /* dartbug.com/16401 Function */ fn;
+  final List<AST> argsAST;
+
+  PureFunctionAST(name, this.fn, argsAST)
+      : super('$name(${_argList(argsAST)})'),
+        argsAST = argsAST,
+        name = name;
+
+  WatchRecord<_Handler> setupWatch(WatchGroup watchGroup) =>
+      watchGroup.addFunctionWatch(fn, argsAST, expression);
+}
+
+/**
+ * SYNTAX: lhs.method(arg0, arg1, ...)
+ *
+ * Invoke a method on [lhs] object.
+ */
+class MethodAST extends AST {
+  final AST lhsAST;
+  final String name;
+  final List<AST> argsAST;
+
+  MethodAST(lhsAST, name, argsAST)
+      : super('$lhsAST.$name(${_argList(argsAST)})'),
+        lhsAST = lhsAST,
+        name = name,
+        argsAST = argsAST;
+
+  WatchRecord<_Handler> setupWatch(WatchGroup watchGroup) =>
+      watchGroup.addMethodWatch(lhsAST, name, argsAST, expression);
+}
+
+
+class CollectionAST extends AST {
+  final AST valueAST;
+  CollectionAST(valueAST)
+      : valueAST = valueAST,
+        super('#collection($valueAST)');
+
+  WatchRecord<_Handler> setupWatch(WatchGroup watchGroup) =>
+      watchGroup.addCollectionWatch(valueAST);
+}
+
+String _argList(List<AST> items) => items.join(', ');
+
+/**
+ * The name is a bit oxymoron, but it is essentially the NullObject pattern.
+ *
+ * This allows children to set a handler on this ChangeRecord and then let it write the initial
+ * constant value to the forwarding ChangeRecord.
+ */
+class _ConstantWatchRecord extends WatchRecord<_Handler> {
+  final currentValue;
+  final _Handler handler;
+
+  _ConstantWatchRecord(WatchGroup watchGroup, String expression, currentValue)
+      : currentValue = currentValue,
+        handler = new _ConstantHandler(watchGroup, expression, currentValue);
+
+  ChangeRecord<_Handler> check() => null;
+  void remove() => null;
+
+  get field => null;
+  get previousValue => null;
+  get object => null;
+  set object(_) => null;
+  get nextChange => null;
+}
+