pkg/unittest: Run each test in a Zone

pkg/unittest/lib/unittest.dart

 // Copyright (c) 2013, 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.
 
 /**
  * Support for writing Dart unit tests.
  *
  * For information on installing and importing this library, see the
  * [unittest package on pub.dartlang.org]
  * (http://pub.dartlang.org/packages/unittest).
@@ skipping 353 matching lines @@
 
 /**
  * Like [expectAsyncUntil0] but [callback] should take 2 positional arguments.
  */
 // TODO(sigmund): deprecate this API when issue 2706 is fixed.
 Function expectAsyncUntil2(Function callback, Function isDone, {String id}) {
   return new _SpreadArgsHelper(callback, 0, -1, isDone, id).invoke2;
 }
 
 /**
- * Wraps the [callback] in a new function and returns that function. The new
- * function will be able to handle exceptions by directing them to the correct
- * test. This is thus similar to expectAsync0. Use it to wrap any callbacks that
- * might optionally be called but may never be called during the test.
- * [callback] should take 0 positional arguments (named arguments are not
- * supported). [id] can be used to identify the callback in error
- * messages (for example if it is called after the test case is complete).
+ * *Deprecated*
+ *
+ * All tests are now run an isolated [Zone].
+ *
+ * You can safely remove calls to this method.
  */
-// TODO(sigmund): deprecate this API when issue 2706 is fixed.
+@deprecated
 Function protectAsync0(Function callback, {String id}) {
-  return new _SpreadArgsHelper(callback, 0, -1, null, id).invoke0;
+  return callback;
 }
 
 /**
- * Like [protectAsync0] but [callback] should take 1 positional argument.
+ * *Deprecated*
+ *
+ * All tests are now run an isolated [Zone].
+ *
+ * You can safely remove calls to this method.
  */
-// TODO(sigmund): deprecate this API when issue 2706 is fixed.
+@deprecated
 Function protectAsync1(Function callback, {String id}) {
-  return new _SpreadArgsHelper(callback, 0, -1, null, id).invoke1;
+  return callback;
 }
 
 /**
- * Like [protectAsync0] but [callback] should take 2 positional arguments.
+ * *Deprecated*
+ *
+ * All tests are now run an isolated [Zone].
+ *
+ * You can safely remove calls to this method.
  */
-// TODO(sigmund): deprecate this API when issue 2706 is fixed.
+@deprecated
 Function protectAsync2(Function callback, {String id}) {
-  return new _SpreadArgsHelper(callback, 0, -1, null, id).invoke2;
+  return callback;

[Siggi Cherem (dart-lang), 2014/02/04 02:20:05]

not sure if this works. runZoned only intercepts 0 and 1 arg methods.

[kevmoo, 2014/02/04 02:26:18]

This is basically a no-op. The assumption is that  callback (in this case) is a
two-argument method. It will be return as such and called as such.

Everything is run in a zone, so it's fine to make all of these no-ops

[nweiz, 2014/02/04 02:34:26]

I don't think this is accurate. All asynchronous callbacks that are scheduled by
a dart: library are intercepted by [runZoned].

[Siggi Cherem (dart-lang), 2014/02/04 02:42:01]

To clarify what my worry was. Zones used to only have logic to wrap 0 and 1 arg
callbacks. It seems that now they also wrap callbacks with 2 args. "Everything
is run in a zone" used to be true only if there were no 2-arg callbacks in the
entire system (dart:io/async/html). Turns out that 'dart:html' has some 2-arg
callbacks (e.g. mutation obsevers). Now that they have binary callbacks included
in zones, we only have to worry about 3-arg callbacks (for which we seem to have
only one in dart:html and I'm not even sure it is asynchronous)

[kevmoo, 2014/02/04 02:45:28]

I'm not sure how Zones handle callbacks with N arguments.

I'm side-stepping this issue by wrapping the call to runTest (which has zero
arguments) in the Zone.

I'm a bit confused where in the Zone logic there is a concept of the number of
arguments you speak of...

 }
 
 /**
  * Creates a new named group of tests. Calls to group() or test() within the
  * body of the function passed to this will inherit this group's description.
  */
 void group(String description, void body()) {
   ensureInitialized();
   _requireNotRunning();
   _currentContext = new _GroupContext(_currentContext, description);
@@ skipping 99 matching lines @@
 /** Runs all queued tests, one at a time. */
 void runTests() {
   _requireNotRunning();
   _ensureInitialized(false);
   _currentTestCaseIndex = 0;
   _config.onStart();
   _runTest();
 }
 
 /**
- * Run [tryBody] guarded in a try-catch block. If an exception is thrown, it is
- * passed to the corresponding test.
+ * *Deprecated*
  *
- * The value returned by [tryBody] (if any) is returned by [guardAsync].
+ * All tests are now run an isolated [Zone].
+ *
+ * You can safely remove calls to this method.
  */
+@deprecated
 guardAsync(Function tryBody) {
-  return _guardAsync(tryBody, null, currentTestCase);
-}
-
-_guardAsync(Function tryBody, Function finallyBody, TestCase testCase) {
-  assert(testCase != null);
-  try {
-    return tryBody();
-  } catch (e, trace) {
-    _registerException(testCase, e, trace);
-  } finally {
-    if (finallyBody != null) finallyBody();
-  }
+  return tryBody();
 }
 
 /**
  * Registers that an exception was caught for the current test.
  */
 void registerException(e, [trace]) {
   _registerException(currentTestCase, e, trace);
 }
 
 /**
@@ skipping 10 matching lines @@
 
 /**
  * Runs the next test.
  */
 void _runTest() {
   if (_currentTestCaseIndex >= testCases.length) {
     assert(_currentTestCaseIndex == testCases.length);
     _completeTests();
   } else {
     var testCase = testCases[_currentTestCaseIndex];
-    Future f = _guardAsync(testCase._run, null, testCase);
+    Future f = runZoned(testCase._run, onError: (error, stack) {
+      _registerException(testCase, error, stack);
+    });
+
     var timeout = unittestConfiguration.timeout;
 
     Timer timer;
     if (timeout != null) {
       try {
         timer = new Timer(timeout, () {
           testCase._error("Test timed out after ${timeout.inSeconds} seconds.");
           _nextTestCase();
         });
       } on UnsupportedError catch (e) {
@@ skipping 132 matching lines @@
 
   if (!filterStacks) return trace;
 
   // Format the stack trace by removing everything above TestCase._runTest,
   // which is usually going to be irrelevant. Also fold together unittest and
   // core library calls so only the function the user called is visible.
   return new Trace(trace.frames.takeWhile((frame) {
     return frame.package != 'unittest' || frame.member != 'TestCase._runTest';
   })).terse.foldFrames((frame) => frame.package == 'unittest' || frame.isCore);
 }