Adding Angular and dependent packages for testing

third_party/pkg/angular/lib/core_dom/directive.dart

+part of angular.core.dom;
+
+/**
+ * Callback function used to notify of attribute changes.
+ */
+typedef AttributeChanged(String newValue);
+
+/**
+ * Callback function used to notify of text changes.
+ */
+abstract class TextChangeListener{
+  call(String text);
+}
+
+
+/**
+ * NodeAttrs is a facade for element attributes. The facade is responsible
+ * for normalizing attribute names as well as allowing access to the
+ * value of the directive.
+ */
+class NodeAttrs {
+  final dom.Element element;
+
+  Map<String, List<AttributeChanged>> _observers;
+
+  NodeAttrs(this.element);
+
+  operator [](String name) => element.attributes[_snakeCase(name, '-')];
+
+  operator []=(String name, String value) {
+    name = _snakeCase(name, '-');
+    if (value == null) {
+      element.attributes.remove(name);
+    } else {
+      element.attributes[name] = value;
+    }
+    if (_observers != null && _observers.containsKey(name)) {
+      _observers[name].forEach((fn) => fn(value));
+    }
+  }
+
+  /**
+   * Observe changes to the attribute by invoking the [AttributeChanged]
+   * function. On registration the [AttributeChanged] function gets invoked
+   * synchronise with the current value.
+   */
+  observe(String attributeName, AttributeChanged notifyFn) {
+    attributeName = _snakeCase(attributeName, '-');
+    if (_observers == null) {
+      _observers = new Map<String, List<AttributeChanged>>();
+    }
+    if (!_observers.containsKey(attributeName)) {
+      _observers[attributeName] = new List<AttributeChanged>();
+    }
+    _observers[attributeName].add(notifyFn);
+    notifyFn(this[attributeName]);
+  }
+}
+
+/**
+ * TemplateLoader is an asynchronous access to ShadowRoot which is
+ * loaded asynchronously. It allows a Component to be notified when its
+ * ShadowRoot is ready.
+ */
+class TemplateLoader {
+  final async.Future<dom.ShadowRoot> _template;
+
+  async.Future<dom.ShadowRoot> get template => _template;
+
+  TemplateLoader(this._template);
+}
+
+var _SNAKE_CASE_REGEXP = new RegExp("[A-Z]");
+String _snakeCase(String name, [separator = '_']) {
+  _snakeReplace(Match match) =>
+    (match.start != 0 ? separator : '') + match.group(0).toLowerCase();
+
+  return name.replaceAllMapped(_SNAKE_CASE_REGEXP, _snakeReplace);
+}