Added support for layout render tests. These use expected values for the text render output from Du…

pkg/unittest/config.dart

 // Copyright (c) 2011, 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.
 
 /** This file is sourced by unitest.dart. */
 
 /**
  * Hooks to configure the unittest library for different platforms. This class
  * implements the API in a platform-independent way. Tests that want to take
  * advantage of the platform can create a subclass and override methods from
  * this class.
  */
 class Configuration {
   TestCase currentTestCase = null;
 
   /**
+   * Subclasses can override this with something useful for diagnostics.
+   * Particularly useful in cases where we have parent/child configurations
+   * such as layout tests.
+   */
+  get name => 'Configuration';
+  /**
    * If true, then tests are started automatically (otherwise [runTests]
    * must be called explicitly after the tests are set up.
    */
   get autoStart => true;
 
   /**
    * Called as soon as the unittest framework becomes initialized. This is done
    * even before tests are added to the test framework. It might be used to
    * determine/debug errors that occur before the test harness starts executing.
    */
@@ skipping 20 matching lines @@
    */
   void onTestResult(TestCase testCase) {
     currentTestCase = null;
   }
 
   /**
    * Can be called by tests to log status. Tests should use this
    * instead of print. Subclasses should not override this; they
    * should instead override logMessage which is passed the test case.
    */
-  void log(String message) {
+  void logMessage(String message) {
     if (currentTestCase == null || _currentTest >= _tests.length ||
         currentTestCase.id != _tests[_currentTest].id) {
       // Before or after tests run, or with a mismatch between what the
       // config and the test harness think is the current test. In this
       // case we pass null for the test case reference and let the config
       // decide what to do with this.
-      logMessage(null, message);
+      logTestCaseMessage(null, message);
     } else {
-      logMessage(currentTestCase, message);
+      logTestCaseMessage(currentTestCase, message);
     }
   }
 
   /**
    * Handles the logging of messages by a test case. The default in
    * this base configuration is to call print();
    */
-  void logMessage(TestCase testCase, String message) {
+  void logTestCaseMessage(TestCase testCase, String message) {
     print(message);
   }
 
   /**
    * Called with the result of all test cases. The default implementation prints
    * the result summary using the built-in [print] command. Browser tests
    * commonly override this to reformat the output.
    *
    * When [uncaughtError] is not null, it contains an error that occured outside
    * of tests (e.g. setting up the test).
@@ skipping 40 matching lines @@
 
     return Strings.join(str.split("\n").map((line) => "  $line"), "\n");
   }
 
   /** Handle errors that happen outside the tests. */
   // TODO(vsm): figure out how to expose the stack trace here
   // Currently e.message works in dartium, but not in dartc.
   handleExternalError(e, String message) =>
       _reportTestError('$message\nCaught $e', '');
 }