Roll Observatory packages and add a roll script

packages/pool/test/pool_test.dart

+// Copyright (c) 2014, 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:fake_async/fake_async.dart';
+import 'package:pool/pool.dart';
+import 'package:stack_trace/stack_trace.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group("request()", () {
+    test("resources can be requested freely up to the limit", () {
+      var pool = new Pool(50);
+      for (var i = 0; i < 50; i++) {
+        expect(pool.request(), completes);
+      }
+    });
+
+    test("resources block past the limit", () {
+      new FakeAsync().run((async) {
+        var pool = new Pool(50);
+        for (var i = 0; i < 50; i++) {
+          expect(pool.request(), completes);
+        }
+        expect(pool.request(), doesNotComplete);
+
+        async.elapse(new Duration(seconds: 1));
+      });
+    });
+
+    test("a blocked resource is allocated when another is released", () {
+      new FakeAsync().run((async) {
+        var pool = new Pool(50);
+        for (var i = 0; i < 49; i++) {
+          expect(pool.request(), completes);
+        }
+
+        pool.request().then((lastAllocatedResource) {
+          // This will only complete once [lastAllocatedResource] is released.
+          expect(pool.request(), completes);
+
+          new Future.delayed(new Duration(microseconds: 1)).then((_) {
+            lastAllocatedResource.release();
+          });
+        });
+
+        async.elapse(new Duration(seconds: 1));
+      });
+    });
+  });
+
+  group("withResource()", () {
+    test("can be called freely up to the limit", () {
+      var pool = new Pool(50);
+      for (var i = 0; i < 50; i++) {
+        pool.withResource(expectAsync(() => new Completer().future));
+      }
+    });
+
+    test("blocks the callback past the limit", () {
+      new FakeAsync().run((async) {
+        var pool = new Pool(50);
+        for (var i = 0; i < 50; i++) {
+          pool.withResource(expectAsync(() => new Completer().future));
+        }
+        pool.withResource(expectNoAsync());
+
+        async.elapse(new Duration(seconds: 1));
+      });
+    });
+
+    test("a blocked resource is allocated when another is released", () {
+      new FakeAsync().run((async) {
+        var pool = new Pool(50);
+        for (var i = 0; i < 49; i++) {
+          pool.withResource(expectAsync(() => new Completer().future));
+        }
+
+        var completer = new Completer();
+        pool.withResource(() => completer.future);
+        var blockedResourceAllocated = false;
+        pool.withResource(() {
+          blockedResourceAllocated = true;
+        });
+
+        new Future.delayed(new Duration(microseconds: 1)).then((_) {
+          expect(blockedResourceAllocated, isFalse);
+          completer.complete();
+          return new Future.delayed(new Duration(microseconds: 1));
+        }).then((_) {
+          expect(blockedResourceAllocated, isTrue);
+        });
+
+        async.elapse(new Duration(seconds: 1));
+      });
+    });
+  });
+
+  group("with a timeout", () {
+    test("doesn't time out if there are no pending requests", () {
+      new FakeAsync().run((async) {
+        var pool = new Pool(50, timeout: new Duration(seconds: 5));
+        for (var i = 0; i < 50; i++) {
+          expect(pool.request(), completes);
+        }
+
+        async.elapse(new Duration(seconds: 6));
+      });
+    });
+
+    test("resets the timer if a resource is returned", () {
+      new FakeAsync().run((async) {
+        var pool = new Pool(50, timeout: new Duration(seconds: 5));
+        for (var i = 0; i < 49; i++) {
+          expect(pool.request(), completes);
+        }
+
+        pool.request().then((lastAllocatedResource) {
+          // This will only complete once [lastAllocatedResource] is released.
+          expect(pool.request(), completes);
+
+          new Future.delayed(new Duration(seconds: 3)).then((_) {
+            lastAllocatedResource.release();
+            expect(pool.request(), doesNotComplete);
+          });
+        });
+
+        async.elapse(new Duration(seconds: 6));
+      });
+    });
+
+    test("resets the timer if a resource is requested", () {
+      new FakeAsync().run((async) {
+        var pool = new Pool(50, timeout: new Duration(seconds: 5));
+        for (var i = 0; i < 50; i++) {
+          expect(pool.request(), completes);
+        }
+        expect(pool.request(), doesNotComplete);
+
+        new Future.delayed(new Duration(seconds: 3)).then((_) {
+          expect(pool.request(), doesNotComplete);
+        });
+
+        async.elapse(new Duration(seconds: 6));
+      });
+    });
+
+    test("times out if nothing happens", () {
+      new FakeAsync().run((async) {
+        var pool = new Pool(50, timeout: new Duration(seconds: 5));
+        for (var i = 0; i < 50; i++) {
+          expect(pool.request(), completes);
+        }
+        expect(pool.request(), throwsA(new isInstanceOf<TimeoutException>()));
+
+        async.elapse(new Duration(seconds: 6));
+      });
+    });
+  });
+
+  group("allowRelease()", () {
+    test("runs the callback once the resource limit is exceeded", () async {
+      var pool = new Pool(50);
+      for (var i = 0; i < 49; i++) {
+        expect(pool.request(), completes);
+      }
+
+      var resource = await pool.request();
+      var onReleaseCalled = false;
+      resource.allowRelease(() => onReleaseCalled = true);
+      await new Future.delayed(Duration.ZERO);
+      expect(onReleaseCalled, isFalse);
+
+      expect(pool.request(), completes);
+      await new Future.delayed(Duration.ZERO);
+      expect(onReleaseCalled, isTrue);
+    });
+
+    test("runs the callback immediately if there are blocked requests",
+        () async {
+      var pool = new Pool(1);
+      var resource = await pool.request();
+
+      // This will be blocked until [resource.allowRelease] is called.
+      expect(pool.request(), completes);
+
+      var onReleaseCalled = false;
+      resource.allowRelease(() => onReleaseCalled = true);
+      await new Future.delayed(Duration.ZERO);
+      expect(onReleaseCalled, isTrue);
+    });
+
+    test("blocks the request until the callback completes", () async {
+      var pool = new Pool(1);
+      var resource = await pool.request();
+
+      var requestComplete = false;
+      pool.request().then((_) => requestComplete = true);
+
+      var completer = new Completer();
+      resource.allowRelease(() => completer.future);
+      await new Future.delayed(Duration.ZERO);
+      expect(requestComplete, isFalse);
+
+      completer.complete();
+      await new Future.delayed(Duration.ZERO);
+      expect(requestComplete, isTrue);
+    });
+
+    test("completes requests in request order regardless of callback order",
+        () async {
+      var pool = new Pool(2);
+      var resource1 = await pool.request();
+      var resource2 = await pool.request();
+
+      var request1Complete = false;
+      pool.request().then((_) => request1Complete = true);
+      var request2Complete = false;
+      pool.request().then((_) => request2Complete = true);
+
+      var onRelease1Called = false;
+      var completer1 = new Completer();
+      resource1.allowRelease(() {
+        onRelease1Called = true;
+        return completer1.future;
+      });
+      await new Future.delayed(Duration.ZERO);
+      expect(onRelease1Called, isTrue);
+
+      var onRelease2Called = false;
+      var completer2 = new Completer();
+      resource2.allowRelease(() {
+        onRelease2Called = true;
+        return completer2.future;
+      });
+      await new Future.delayed(Duration.ZERO);
+      expect(onRelease2Called, isTrue);
+      expect(request1Complete, isFalse);
+      expect(request2Complete, isFalse);
+
+      // Complete the second resource's onRelease callback first. Even though it
+      // was triggered by the second blocking request, it should complete the
+      // first one to preserve ordering.
+      completer2.complete();
+      await new Future.delayed(Duration.ZERO);
+      expect(request1Complete, isTrue);
+      expect(request2Complete, isFalse);
+
+      completer1.complete();
+      await new Future.delayed(Duration.ZERO);
+      expect(request1Complete, isTrue);
+      expect(request2Complete, isTrue);
+    });
+
+    test("runs onRequest in the zone it was created", () async {
+      var pool = new Pool(1);
+      var resource = await pool.request();
+
+      var outerZone = Zone.current;
+      runZoned(() {
+        var innerZone = Zone.current;
+        expect(innerZone, isNot(equals(outerZone)));
+
+        resource.allowRelease(expectAsync(() {
+          expect(Zone.current, equals(innerZone));
+        }));
+      });
+
+      pool.request();
+    });
+  });
+
+  group("close()", () {
+    test("disallows request() and withResource()", () {
+      var pool = new Pool(1)..close();
+      expect(pool.request, throwsStateError);
+      expect(() => pool.withResource(() {}), throwsStateError);
+    });
+
+    test("pending requests are fulfilled", () async {
+      var pool = new Pool(1);
+      var resource1 = await pool.request();
+      expect(pool.request().then((resource2) {
+        resource2.release();
+      }), completes);
+      expect(pool.close(), completes);
+      resource1.release();
+    });
+
+    test("pending requests are fulfilled with allowRelease", () async {
+      var pool = new Pool(1);
+      var resource1 = await pool.request();
+
+      var completer = new Completer();
+      expect(pool.request().then((resource2) {
+        expect(completer.isCompleted, isTrue);
+        resource2.release();
+      }), completes);
+      expect(pool.close(), completes);
+
+      resource1.allowRelease(() => completer.future);
+      await new Future.delayed(Duration.ZERO);
+
+      completer.complete();
+    });
+
+    test("doesn't complete until all resources are released", () async {
+      var pool = new Pool(2);
+      var resource1 = await pool.request();
+      var resource2 = await pool.request();
+      var resource3Future = pool.request();
+
+      var resource1Released = false;
+      var resource2Released = false;
+      var resource3Released = false;
+      expect(pool.close().then((_) {
+        expect(resource1Released, isTrue);
+        expect(resource2Released, isTrue);
+        expect(resource3Released, isTrue);
+      }), completes);
+
+      resource1Released = true;
+      resource1.release();
+      await new Future.delayed(Duration.ZERO);
+
+      resource2Released = true;
+      resource2.release();
+      await new Future.delayed(Duration.ZERO);
+
+      var resource3 = await resource3Future;
+      resource3Released = true;
+      resource3.release();
+    });
+
+    test("active onReleases complete as usual", () async {
+      var pool = new Pool(1);
+      var resource = await pool.request();
+
+      // Set up an onRelease callback whose completion is controlled by
+      // [completer].
+      var completer = new Completer();
+      resource.allowRelease(() => completer.future);
+      expect(pool.request().then((_) {
+        expect(completer.isCompleted, isTrue);
+      }), completes);
+
+      await new Future.delayed(Duration.ZERO);
+      pool.close();
+
+      await new Future.delayed(Duration.ZERO);
+      completer.complete();
+    });
+
+    test("inactive onReleases fire", () async {
+      var pool = new Pool(2);
+      var resource1 = await pool.request();
+      var resource2 = await pool.request();
+
+      var completer1 = new Completer();
+      resource1.allowRelease(() => completer1.future);
+      var completer2 = new Completer();
+      resource2.allowRelease(() => completer2.future);
+
+      expect(pool.close().then((_) {
+        expect(completer1.isCompleted, isTrue);
+        expect(completer2.isCompleted, isTrue);
+      }), completes);
+
+      await new Future.delayed(Duration.ZERO);
+      completer1.complete();
+
+      await new Future.delayed(Duration.ZERO);
+      completer2.complete();
+    });
+
+    test("new allowReleases fire immediately", () async {
+      var pool = new Pool(1);
+      var resource = await pool.request();
+
+      var completer = new Completer();
+      expect(pool.close().then((_) {
+        expect(completer.isCompleted, isTrue);
+      }), completes);
+
+      await new Future.delayed(Duration.ZERO);
+      resource.allowRelease(() => completer.future);
+
+      await new Future.delayed(Duration.ZERO);
+      completer.complete();
+    });
+
+    test("an onRelease error is piped to the return value", () async {
+      var pool = new Pool(1);
+      var resource = await pool.request();
+
+      var completer = new Completer();
+      resource.allowRelease(() => completer.future);
+
+      expect(pool.close(), throwsA("oh no!"));
+
+      await new Future.delayed(Duration.ZERO);
+      completer.completeError("oh no!");
+    });
+  });
+}
+
+/// Returns a function that will cause the test to fail if it's called.
+///
+/// This should only be called within a [FakeAsync.run] zone.
+Function expectNoAsync() {
+  var stack = new Trace.current(1);
+  return () => registerException(
+      new TestFailure("Expected function not to be called."), stack);
+}
+
+/// A matcher for Futures that asserts that they don't complete.
+///
+/// This should only be called within a [FakeAsync.run] zone.
+Matcher get doesNotComplete => predicate((future) {
+  expect(future, new isInstanceOf<Future>());
+
+  var stack = new Trace.current(1);
+  future.then((_) => registerException(
+      new TestFailure("Expected future not to complete."), stack));
+  return true;
+});