Added the ability to filter which tests are run by name, using a --filter

lib/unittest/unittest.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.
 
 /**
  * A library for writing dart unit tests.
  *
  * To import this library, specify the relative path to
  * lib/unittest/unittest.dart.
  *
@@ skipping 195 matching lines @@
 int _state = _UNINITIALIZED;
 String _uncaughtErrorMessage = null;
 
 final _PASS  = 'pass';
 final _FAIL  = 'fail';
 final _ERROR = 'error';
 
 /** If set, then all other test cases will be ignored. */
 TestCase _soloTest;
 
+/** If set, then only tests whose names match this pattern will be run. */

[eub, 2012/06/21 20:58:45]

s/pattern/regexp/ to be clear.

[eub, 2012/06/21 20:58:45]

Also, s/name/description/ globally unless that's already an established alias.

[gram, 2012/06/21 21:18:03]

Done.

+String _filter = null;
+
 /**
  * (Deprecated) Evaluates the [function] and validates that it throws an
  * exception. If [callback] is provided, then it will be invoked with the
  * thrown exception. The callback may do any validation it wants. In addition,
  * if it returns `false`, that also indicates an expectation failure.
  */
 void expectThrow(function, [bool callback(exception)]) {
   bool threw = false;
   try {
     function();
   } catch (var e) {
     threw = true;
 
     // Also let the callback look at it.
     if (callback != null) {
       var result = callback(e);
 
       // If the callback explicitly returned false, treat that like an
       // expectation too. (If it returns null, though, don't.)
       if (result == false) {
         _fail('Exception:\n$e\ndid not match expectation.');
       }
     }
   }
 
   if (threw != true) _fail('An expected exception was not thrown.');
 }
 
+/** Sets the filter which constrains which tests to run based on their names. */
+void setFilter(String filter) {
+  if (filter == '') filter = null;
+  _filter = filter;
+}
+
+/** Gets the filter which constrains which tests to run based on their names. */
+String getFilter() {
+  return _filter;
+}
 /**
  * Creates a new test case with the given description and body. The
  * description will include the descriptions of any surrounding group()
  * calls.
  */
 void test(String spec, TestFunction body) {
   ensureInitialized();
 
   _tests.add(new TestCase(_tests.length + 1, _fullSpec(spec), body, 0));
 }
@@ skipping 380 matching lines @@
   });
   port.toSendPort().send(null, null);
 }
 
 /** Runs all queued tests, one at a time. */
 _runTests() {
   // If we are soloing a test, remove all the others.
   if (_soloTest != null) {
     _tests = _tests.filter((t) => t == _soloTest);
   }
+  if (_filter == null) { // check arguments for a --filter spec.
+    var options = new Options().arguments;
+    if (options != null) {
+      for (var i = 0; i < options.length; i++) {
+        if (options[i].startsWith('--filter=')) {

[eub, 2012/06/21 20:58:45]

Another one for the Great Flag Parsing Unification of the Future?

+          var filter = options[i].substring(10);

[eub, 2012/06/21 20:58:45]

This chops off the first character, or did I miscount?

[gram, 2012/06/21 21:18:03]

Correct, I was assuming this is quoted. But you're right, that may not be true
and I should make sure, so I've tweaked this.

+          filter = filter.substring(0, filter.length-1);

[eub, 2012/06/21 20:58:45]

And this chops off the last character, so we're consistent... is this expecting
it to come in with quote bracketing or something?

+          setFilter(filter);
+          break;
+        }
+      }
+    }
+  }
+  if (_filter != null) {
+    RegExp re = new RegExp(_filter);
+    _tests = _tests.filter((t) => re.hasMatch(t.description));
+  }
 
   _config.onStart();
 
   _defer(() {
     assert (_currentTest == 0);
     _testRunner();
   });
 }
 
 /**
@@ skipping 102 matching lines @@
   _config.onInit();
 
   // Immediately queue the suite up. It will run after a timeout (i.e. after
   // main() has returned).
   _defer(_runTests);
 }
 
 /** Signature for a test function. */
 typedef void TestFunction();