Add pretty-printing to unittest and more thoroughly print values.

pkg/unittest/lib/src/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.
 
 part of matcher;
 
 /**
  * The default implementation of IDescription. This should rarely need
  * substitution, although conceivably it is a place where other languages
  * could be supported.
@@ skipping 23 matching lines @@
 
   /**
    * 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 if (description.startsWith("Instance of")) {
-        add('<');
-        add(description);
-        add(':');
-        add(value.hashCode.toString());
-        add('>');
-      } else {
-        add('<');
-        add(description);
-        add('>');
-      }
+      add(prettyPrint(value, maxLineLength: 80, maxItems: 25));
     }
     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(escapeString(string));
     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;
-  }
 }