documented component

tools/testing/dart/test_options.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.
 
 #library("test_options_parser");
 
 #import("dart:io");
 
 List<String> defaultTestSelectors =
     const ['dartc', 'samples', 'standalone', 'corelib', 'co19', 'language',
@@ skipping 43 matching lines @@
   TestOptionsParser() {
     _options =
         [ new _TestOptionSpecification(
               'mode',
               'Mode in which to run the tests',
               ['-m', '--mode'],
               ['all', 'debug', 'release'],
               'debug'),
           new _TestOptionSpecification(
               'component',
-              'The component to test against',
+              '''
+Controls how dart code is compiled and executed. 
+
+   vm: Run dart code on the standalone dart vm.
+
+   frog: Compile dart code by running frog on the standalone dart vm, and
+       run the resulting javascript on D8.
+
+   leg: Compile dart code by running leg on the standalone dart vm, and
+       run the resulting javascript on D8.
+
+   frogsh: Compile dart code by running frog on node.js, and run the
+       resulting javascript on the same instance of node.js.
+
+   dartium: Run dart code in a type="application/dart" script tag in a
+       dartium build of DumpRenderTree.
+
+   chromium: Obsolete, not used, will be removed.
+
+   frogium: Compile dart code by running frog on the standalone dart vm,
+       and run the resulting javascript in a javascript script tag in
+       a dartium build of DumpRenderTree.
+
+   legium: Compile dart code by running leg on the standalone dart vm,
+       and run the resulting javascript in a javascript script tag in
+       a dartium build of DumpRenderTree.
+
+   webdriver: Compile dart code by running frog on the standalone dart vm,
+       and then run the resulting javascript in the browser that is specified
+       by the --browser switch (e.g. chrome, safari, ff, etc.).
+
+   dartc: Run dart code through the dartc static analyzer (does not
+       execute dart code).
+''',
               ['-c', '--component'],
               ['most', 'vm', 'dartc', 'frog', 'frogsh', 'leg',
                'dartium', 'chromium', 'frogium', 'legium', 'webdriver'],
               'vm'),
           new _TestOptionSpecification(
               'arch',
               'The architecture to run tests for',
               ['-a', '--arch'],
               ['all', 'ia32', 'x64', 'simarm'],
               'ia32'),
@@ skipping 428 matching lines @@
         return option;
       }
     }
     print('Unknown test option $name');
     exit(1);
   }
 
 
   List<_TestOptionSpecification> _options;
 }