Add support for setUpAll and tearDownAll.

lib/src/backend/declarer.dart

 // Copyright (c) 2015, 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.backend.declarer;
 
 import 'dart:async';
 
 import '../frontend/timeout.dart';
 import '../utils.dart';
 import 'group.dart';
+import 'group_entry.dart';
 import 'invoker.dart';
 import 'metadata.dart';
-import 'group_entry.dart';
+import 'test.dart';
 
 /// A class that manages the state of tests as they're declared.
 ///
 /// A nested tree of Declarers tracks the current group, set-up, and tear-down
 /// functions. Each Declarer in the tree corresponds to a group. This tree is
 /// tracked by a zone-scoped "current" Declarer; the current declarer can be set
 /// for a block using [Declarer.declare], and it can be accessed using
 /// [Declarer.current].
 class Declarer {
   /// The parent declarer, or `null` if this corresponds to the root group.
   final Declarer _parent;
 
   /// The name of the current test group, including the name of any parent
   /// groups.
   ///
   /// This is `null` if this is the root group.
   final String _name;
 
   /// The metadata for this group, including the metadata of any parent groups
   /// and of the test suite.
   final Metadata _metadata;
 
-  /// The set-up functions for this group.
+  /// The set-up functions to run for each test in this group.
   final _setUps = new List<AsyncFunction>();
 
-  /// The tear-down functions for this group.
+  /// The tear-down functions to run for each test in this group.
   final _tearDowns = new List<AsyncFunction>();
 
+  /// The set-up functions to run once for this group.
+  final _setUpAlls = new List<AsyncFunction>();
+
+  /// The tear-down functions to run once for this group.
+  final _tearDownAlls = new List<AsyncFunction>();
+
   /// The children of this group, either tests or sub-groups.
   final _entries = new List<GroupEntry>();
 
   /// Whether [build] has been called for this declarer.
   bool _built = false;
 
   /// The current zone-scoped declarer.
   static Declarer get current => Zone.current[#test.declarer];
 
   /// Creates a new declarer for the root group.
   ///
   /// This is the implicit group that exists outside of any calls to `group()`.
   /// If [metadata] is passed, it's used as the metadata for the implicit root
   /// group.
   Declarer([Metadata metadata])
       : this._(null, null, metadata == null ? new Metadata() : metadata);
 
   Declarer._(this._parent, this._name, this._metadata);
 
   /// Runs [body] with this declarer as [Declarer.current].
   ///
   /// Returns the return value of [body].
   declare(body()) => runZoned(body, zoneValues: {#test.declarer: this});
 
   /// Defines a test case with the given name and body.
   void test(String name, body(), {String testOn, Timeout timeout, skip,
       Map<String, dynamic> onPlatform}) {
-    if (_built) {
-      throw new StateError("Can't call test() once tests have begun running.");
-    }
+    _checkNotBuilt("test");
 
     var metadata = _metadata.merge(new Metadata.parse(
         testOn: testOn, timeout: timeout, skip: skip, onPlatform: onPlatform));
 
     _entries.add(new LocalTest(_prefix(name), metadata, () {
       // TODO(nweiz): It might be useful to throw an error here if a test starts
       // running while other tests from the same declarer are also running,
       // since they might share closurized state.
 
       // TODO(nweiz): Use async/await here once issue 23497 has been fixed in
       // two stable versions.
       return Invoker.current.waitForOutstandingCallbacks(() {
         return _runSetUps().then((_) => body());
       }).then((_) => _runTearDowns());
     }));
   }
 
   /// Creates a group of tests.
   void group(String name, void body(), {String testOn, Timeout timeout, skip,
       Map<String, dynamic> onPlatform}) {
-    if (_built) {
-      throw new StateError("Can't call group() once tests have begun running.");
-    }
+    _checkNotBuilt("group");
 
     var metadata = _metadata.merge(new Metadata.parse(
         testOn: testOn, timeout: timeout, skip: skip, onPlatform: onPlatform));
 
     // Don't load the tests for a skipped group.
     if (metadata.skip) {
       _entries.add(new Group(name, [], metadata: metadata));
       return;
     }
 
     var declarer = new Declarer._(this, _prefix(name), metadata);
     declarer.declare(body);
     _entries.add(declarer.build());
   }
 
   /// Returns [name] prefixed with this declarer's group name.
   String _prefix(String name) => _name == null ? name : "$_name $name";
 
   /// Registers a function to be run before each test in this group.
   void setUp(callback()) {
-    if (_built) {
-      throw new StateError("Can't call setUp() once tests have begun running.");
-    }
-
+    _checkNotBuilt("setUp");
     _setUps.add(callback);
   }
 
   /// Registers a function to be run after each test in this group.
   void tearDown(callback()) {
-    if (_built) {
-      throw new StateError(
-          "Can't call tearDown() once tests have begun running.");
-    }
+    _checkNotBuilt("tearDown");
+    _tearDowns.add(callback);
+  }
 
-    _tearDowns.add(callback);
+  /// Registers a function to be run once before all tests.
+  void setUpAll(callback()) {
+    _checkNotBuilt("setUpAll");
+    _setUpAlls.add(callback);
+  }
+
+  /// Registers a function to be run once after all tests.
+  void tearDownAll(callback()) {
+    _checkNotBuilt("tearDownAll");
+    _tearDownAlls.add(callback);
   }
 
   /// Finalizes and returns the group being declared.
   Group build() {
-    if (_built) {
-      throw new StateError("Can't call Declarer.build() more than once.");
-    }
+    _checkNotBuilt("build");
 
     _built = true;
-    return new Group(_name, _entries.toList(), metadata: _metadata);
+    return new Group(_name, _entries.toList(),
+        metadata: _metadata,
+        setUpAll: _setUpAll,
+        tearDownAll: _tearDownAll);
+  }
+
+  /// Throws a [StateError] if [build] has been called.
+  ///
+  /// [name] should be the name of the method being called.
+  void _checkNotBuilt(String name) {
+    if (!_built) return;
+    throw new StateError("Can't call $name() once tests have begun running.");
   }
 
   /// Run the set-up functions for this and any parent groups.
   ///
   /// If no set-up functions are declared, this returns a [Future] that
   /// completes immediately.
   Future _runSetUps() {
     // TODO(nweiz): Use async/await here once issue 23497 has been fixed in two
     // stable versions.
     if (_parent != null) {
@@ skipping 15 matching lines @@
     return Invoker.current.unclosable(() {
       var tearDowns = [];
       for (var declarer = this; declarer != null; declarer = declarer._parent) {
         tearDowns.addAll(declarer._tearDowns.reversed);
       }
 
       return Future.forEach(tearDowns, _errorsDontStopTest);
     });
   }
 
+  /// Returns a [Test] that runs the callbacks in [_setUpAll].
+  Test get _setUpAll {
+    if (_setUpAlls.isEmpty) return null;
+
+    return new LocalTest(_prefix("(setUpAll)"), _metadata, () {
+      return Future.forEach(_setUpAlls, (setUp) => setUp());
+    });
+  }
+
+  /// Returns a [Test] that runs the callbacks in [_tearDownAll].
+  Test get _tearDownAll {
+    if (_tearDownAlls.isEmpty) return null;
+
+    return new LocalTest(_prefix("(tearDownAll)"), _metadata, () {
+      return Invoker.current.unclosable(() {
+        return Future.forEach(_tearDownAlls.reversed, _errorsDontStopTest);
+      });
+    });
+  }
+
   /// Runs [body] with special error-handling behavior.
   ///
   /// Errors emitted [body] will still cause the current test to fail, but they
   /// won't cause it to *stop*. In particular, they won't remove any outstanding
   /// callbacks registered outside of [body].
   Future _errorsDontStopTest(body()) {
     var completer = new Completer();
 
     Invoker.current.addOutstandingCallback();
     Invoker.current.waitForOutstandingCallbacks(() {
       new Future.sync(body).whenComplete(completer.complete);
     }).then((_) => Invoker.current.removeOutstandingCallback());
 
     return completer.future;
   }
 }