Chaining of setup/teardown.

pkg/unittest/lib/unittest.dart

Index: pkg/unittest/lib/unittest.dart
===================================================================
--- pkg/unittest/lib/unittest.dart	(revision 21816)
+++ pkg/unittest/lib/unittest.dart	(working copy)
@@ -205,12 +205,6 @@
 void logMessage(String message) =>
     _config.onLogMessage(currentTestCase, message);
 
-/**
- * Description text of the current test group. If multiple groups are nested,
- * this will contain all of their text concatenated.
- */
-String _currentGroup = '';
-
 /** Separator used between group names and test names. */
 String groupSep = ' ';
 
@@ -219,12 +213,30 @@
 /** Tests executed in this suite. */
 final List<TestCase> testCases = new UnmodifiableListView<TestCase>(_testCases);
 
-/** Setup function called before each test in a group */
-Function _testSetup;
+/**
+ * Setup and teardown functions for a group and its parents, the latter
+ * for chaining.
+ */
+class GroupContext {
+  /** Setup function called before each test in a group. */
+  Function testSetup = null;
 
-/** Teardown function called after each test in a group */
-Function _testTeardown;
+  /** Teardown function called after each test in a group. */
+  Function testTeardown = null;
 
+  /** Setup and teardown functions of parent group, for chaining. */
+  Function parentSetup = null;
+  Function parentTeardown = null;
+
+  /**
+   * Description text of the current test group. If multiple groups are nested,
+   * this will contain all of their text concatenated.
+   */
+  String groupName = '';
+}
+
+GroupContext _currentContext = new GroupContext();
+
 int _currentTestCaseIndex = 0;
 
 /** [TestCase] currently being executed. */
@@ -596,46 +608,55 @@
  */
 void group(String description, void body()) {
   ensureInitialized();
+  // Groups can be nested, so we need to preserve the current
+  // settings for test setup/teardown. We use a local copy here so we
+  // can nest multiple levels; we also have the global parent variables
+  // which are used for chaining.
+  var oldContext = _currentContext;
+  _currentContext = new GroupContext();
+  _currentContext.testSetup = _currentContext.parentSetup =
+      oldContext.testSetup;
+  _currentContext.testTeardown = _currentContext.parentTeardown =
+      oldContext.testTeardown;
+
   // Concatenate the new group.
-  final parentGroup = _currentGroup;
-  if (_currentGroup != '') {
+  if (oldContext.groupName != '') {
     // Add a space.
-    _currentGroup = '$_currentGroup$groupSep$description';
+    _currentContext.groupName = '${oldContext.groupName}$groupSep$description';
   } else {
     // The first group.
-    _currentGroup = description;
+    _currentContext.groupName = description;
   }
 
-  // Groups can be nested, so we need to preserve the current
-  // settings for test setup/teardown.
-  Function parentSetup = _testSetup;
-  Function parentTeardown = _testTeardown;
 
   try {
-    _testSetup = null;
-    _testTeardown = null;
     body();
   } catch (e, trace) {
     var stack = (trace == null) ? '' : ': ${trace.toString()}';
     _uncaughtErrorMessage = "${e.toString()}$stack";
   } finally {
     // Now that the group is over, restore the previous one.
-    _currentGroup = parentGroup;
-    _testSetup = parentSetup;
-    _testTeardown = parentTeardown;
+    _currentContext = oldContext;
   }
 }
 
 /**
  * Register a [setUp] function for a test [group]. This function will
- * be called before each test in the group is run. Note that if groups
- * are nested only the most locally scoped [setUpTest] function will be run.
+ * be called before each test in the group is run.
  * [setUp] and [tearDown] should be called within the [group] before any
  * calls to [test]. The [setupTest] function can be asynchronous; in this
  * case it must return a [Future].
  */
 void setUp(Function setupTest) {
-  _testSetup = setupTest;
+  var parent = _currentContext.parentSetup;
+  _currentContext.testSetup = () {
+    var f = parent == null ? null : parent();
+    if (f is Future) {
+      return f.then((_) => setupTest());
+    } else {
+      return setupTest();
+    }
+  };
 }
 
 /**
@@ -647,7 +668,19 @@
  * case it must return a [Future].
  */
 void tearDown(Function teardownTest) {
-  _testTeardown = teardownTest;
+  var parent = _currentContext.parentTeardown;
+  _currentContext.testTeardown = () {
+    var f = teardownTest();
+    if (parent == null) return f;
+    if (f is Future) {
+      // TODO(gram): as _parentTeardown is a global, do we need
+      // to first take a local copy so the value is fixed at the
+      // point that tearDown is called?
+      return f.then((_) => parent());
+    } else {
+      return parent();
+    }
+  };
 }
 
 /** Advance to the next test case. */
@@ -712,7 +745,7 @@
 void runTests() {
   _ensureInitialized(false);
   _currentTestCaseIndex = 0;
-  _currentGroup = '';
+  _currentContext = new GroupContext();
 
   // If we are soloing a test, remove all the others.
   if (_soloTest != null) {
@@ -811,8 +844,9 @@
 }
 
 String _fullSpec(String spec) {
-  if (spec == null) return '$_currentGroup';
-  return _currentGroup != '' ? '$_currentGroup$groupSep$spec' : spec;
+  var group = '${_currentContext.groupName}';
+  if (spec == null) return group;
+  return group != '' ? '$group$groupSep$spec' : spec;
 }
 
 /**