Roll Observatory packages and add a roll script

packages/async/test/future_group_test.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.
+
+import 'dart:async';
+
+import 'package:async/src/future_group.dart';
+import 'package:test/test.dart';
+
+import 'utils.dart';
+
+void main() {
+  var futureGroup;
+  setUp(() {
+    futureGroup = new FutureGroup();
+  });
+
+  group("with no futures", () {
+    test("never completes if nothing happens", () async {
+      var completed = false;
+      futureGroup.future.then((_) => completed = true);
+
+      await flushMicrotasks();
+      expect(completed, isFalse);
+    });
+
+    test("completes once it's closed", () {
+      expect(futureGroup.future, completion(isEmpty));
+      futureGroup.close();
+    });
+  });
+
+  group("with a future that already completed", () {
+    test("never completes if nothing happens", () async {
+      futureGroup.add(new Future.value());
+      await flushMicrotasks();
+
+      var completed = false;
+      futureGroup.future.then((_) => completed = true);
+
+      await flushMicrotasks();
+      expect(completed, isFalse);
+    });
+
+    test("completes once it's closed", () async {
+      futureGroup.add(new Future.value());
+      await flushMicrotasks();
+
+      expect(futureGroup.future, completes);
+      futureGroup.close();
+    });
+
+    test("completes to that future's value", () {
+      futureGroup.add(new Future.value(1));
+      futureGroup.close();
+      expect(futureGroup.future, completion(equals([1])));
+    });
+
+    test("completes to that future's error, even if it's not closed", () {
+      futureGroup.add(new Future.error("error"));
+      expect(futureGroup.future, throwsA("error"));
+    });
+  });
+
+  test("completes once all contained futures complete", () async {
+    var completer1 = new Completer();
+    var completer2 = new Completer();
+    var completer3 = new Completer();
+
+    futureGroup.add(completer1.future);
+    futureGroup.add(completer2.future);
+    futureGroup.add(completer3.future);
+    futureGroup.close();
+
+    var completed = false;
+    futureGroup.future.then((_) => completed = true);
+
+    completer1.complete();
+    await flushMicrotasks();
+    expect(completed, isFalse);
+
+    completer2.complete();
+    await flushMicrotasks();
+    expect(completed, isFalse);
+
+    completer3.complete();
+    await flushMicrotasks();
+    expect(completed, isTrue);
+  });
+
+  test("completes to the values of the futures in order of addition", () {
+    var completer1 = new Completer();
+    var completer2 = new Completer();
+    var completer3 = new Completer();
+
+    futureGroup.add(completer1.future);
+    futureGroup.add(completer2.future);
+    futureGroup.add(completer3.future);
+    futureGroup.close();
+
+    // Complete the completers in reverse order to prove that that doesn't
+    // affect the result order.
+    completer3.complete(3);
+    completer2.complete(2);
+    completer1.complete(1);
+    expect(futureGroup.future, completion(equals([1, 2, 3])));
+  });
+
+  test("completes to the first error to be emitted, even if it's not closed",
+      () {
+    var completer1 = new Completer();
+    var completer2 = new Completer();
+    var completer3 = new Completer();
+
+    futureGroup.add(completer1.future);
+    futureGroup.add(completer2.future);
+    futureGroup.add(completer3.future);
+
+    completer2.completeError("error 2");
+    completer1.completeError("error 1");
+    expect(futureGroup.future, throwsA("error 2"));
+  });
+
+  group("onIdle:", () {
+    test("emits an event when the last pending future completes", () async {
+      var idle = false;
+      futureGroup.onIdle.listen((_) => idle = true);
+
+      var completer1 = new Completer();
+      var completer2 = new Completer();
+      var completer3 = new Completer();
+
+      futureGroup.add(completer1.future);
+      futureGroup.add(completer2.future);
+      futureGroup.add(completer3.future);
+
+      await flushMicrotasks();
+      expect(idle, isFalse);
+      expect(futureGroup.isIdle, isFalse);
+
+      completer1.complete();
+      await flushMicrotasks();
+      expect(idle, isFalse);
+      expect(futureGroup.isIdle, isFalse);
+
+      completer2.complete();
+      await flushMicrotasks();
+      expect(idle, isFalse);
+      expect(futureGroup.isIdle, isFalse);
+
+      completer3.complete();
+      await flushMicrotasks();
+      expect(idle, isTrue);
+      expect(futureGroup.isIdle, isTrue);
+    });
+
+    test("emits an event each time it becomes idle", () async {
+      var idle = false;
+      futureGroup.onIdle.listen((_) => idle = true);
+
+      var completer = new Completer();
+      futureGroup.add(completer.future);
+
+      completer.complete();
+      await flushMicrotasks();
+      expect(idle, isTrue);
+      expect(futureGroup.isIdle, isTrue);
+
+      idle = false;
+      completer = new Completer();
+      futureGroup.add(completer.future);
+
+      await flushMicrotasks();
+      expect(idle, isFalse);
+      expect(futureGroup.isIdle, isFalse);
+
+      completer.complete();
+      await flushMicrotasks();
+      expect(idle, isTrue);
+      expect(futureGroup.isIdle, isTrue);
+    });
+
+    test("emits an event when the group closes", () async {
+      // It's important that the order of events here stays consistent over
+      // time, since code may rely on it in subtle ways.
+      var idle = false;
+      var onIdleDone = false;
+      var futureFired = false;
+
+      futureGroup.onIdle.listen(expectAsync((_) {
+        expect(futureFired, isFalse);
+        idle = true;
+      }), onDone: expectAsync(() {
+        expect(idle, isTrue);
+        expect(futureFired, isFalse);
+        onIdleDone = true;
+      }));
+
+      futureGroup.future.then(expectAsync((_) {
+        expect(idle, isTrue);
+        expect(onIdleDone, isTrue);
+        futureFired = true;
+      }));
+
+      var completer = new Completer();
+      futureGroup.add(completer.future);
+      futureGroup.close();
+
+      await flushMicrotasks();
+      expect(idle, isFalse);
+      expect(futureGroup.isIdle, isFalse);
+
+      completer.complete();
+      await flushMicrotasks();
+      expect(idle, isTrue);
+      expect(futureGroup.isIdle, isTrue);
+      expect(futureFired, isTrue);
+    });
+  });
+}