New expectation functions plus convert old tests to use these.

lib/unittest/description.dart

+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+/**
+ * The default implementation of IDescription. This should rarely need
+ * substitution, although conceivably it is a place where other languages
+ * could be supported.
+ */
+
+class StringDescription implements Description {
+  var _out = '';
+
+  /**
+   * Get the description as a string.
+   */
+  String toString() => _out;
+
+  /**
+   * Append some plain [text] to the description.
+   */
+  Description add(String text) {
+    _out = '${_out}${text}';
+    return this;
+  }
+
+  /**
+   * Appends a description of [value]. If it is an IMatcher use its
+   * describe method; if it is a string use its literal value after
+   * escaping any embedded control characters; otherwise use its
+   * toString() value and wrap it in angular "quotes".
+   */
+  Description addDescriptionOf(value) {
+    if (value is Matcher) {
+      value.describe(this);
+    } else if (value is String) {
+      _addEscapedString(value);
+    } else {
+      String description = (value == null) ? "null" : value.toString();
+      if (description.startsWith('<') && description.endsWith('>')) {
+          add(description);
+      } else {
+        add('<');
+        add(description);
+        add('>');
+      }
+    }
+    return this;
+  }
+
+  /**
+   * Append an [Iterable] [list] of objects to the description, using the
+   * specified [separator] and framing the list with [start]
+   * and [end].
+   */
+  Description addAll(String start, String separator, String end,
+                       Iterable list) {
+    var separate = false;
+    add(start);
+    for (var item in list) {
+      if (separate) {
+        add(separator);
+      }
+      addDescriptionOf(item);
+      separate = true;
+    }
+    add(end);
+    return this;
+  }
+
+  /** Escape the control characters in [string] so that they are visible. */
+  _addEscapedString(String string) {
+    add("'");
+    for (var i = 0; i < string.length; i++) {
+      add(_escape(string[i]));
+    }
+    add("'");
+  }
+
+  /** Return the escaped form of a character [ch]. */
+  _escape(ch) {
+    if (ch == "'")
+      return "\'";
+    else if (ch == '\n')
+      return '\\n';
+    else if (ch == '\r')
+      return '\\r';
+    else if (ch == '\t')
+      return '\\t';
+    else
+      return ch;
+  }
+}