Roll Observatory packages and add a roll script

packages/quiver/test/streams/streambuffer_test.dart

+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+library quiver.streams.streambuffer_test;
+
+import 'dart:async';
+import 'package:test/test.dart';
+import 'package:quiver/streams.dart';
+
+void main() {
+  group("StreamBuffer", () {
+    test("returns orderly overlaps", () {
+      StreamBuffer<int> buf = new StreamBuffer();
+      new Stream.fromIterable([[1], [2, 3, 4], [5, 6, 7, 8]]).pipe(buf);
+      return Future.wait([buf.read(2), buf.read(4), buf.read(2)]).then((vals) {
+        expect(vals[0], equals([1, 2]));
+        expect(vals[1], equals([3, 4, 5, 6]));
+        expect(vals[2], equals([7, 8]));
+      }).then((_) {
+        buf.close();
+      });
+    });
+
+    test("respects pausing of stream", () {
+      StreamBuffer<int> buf = new StreamBuffer()..limit = 2;
+      new Stream.fromIterable([[1], [2], [3], [4]]).pipe(buf);
+      return buf.read(2).then((val) {
+        expect(val, [1, 2]);
+      }).then((_) {
+        return buf.read(2);
+      }).then((val) {
+        expect(val, [3, 4]);
+      });
+    });
+
+    test("throws when reading too much", () {
+      StreamBuffer<int> buf = new StreamBuffer()..limit = 1;
+      new Stream.fromIterable([[1], [2]]).pipe(buf);
+      try {
+        buf.read(2);
+      } catch (e) {
+        expect(e, isArgumentError);
+        return;
+      }
+      fail("error not thrown when reading more data than buffer limit");
+    });
+
+    test("allows patching of streams", () {
+      StreamBuffer<int> buf = new StreamBuffer();
+      new Stream.fromIterable([1, 2]).pipe(buf).then((_) {
+        return new Stream.fromIterable([3, 4]).pipe(buf);
+      });
+      return Future.wait([buf.read(1), buf.read(2), buf.read(1)]).then((vals) {
+        expect(vals[0], equals([1]));
+        expect(vals[1], equals([2, 3]));
+        expect(vals[2], equals([4]));
+      });
+    });
+
+    test("underflows when asked to", () {
+      StreamBuffer<int> buf = new StreamBuffer(throwOnError: true);
+      var error;
+      var future = buf.read(4).then((bytes) {
+        fail("should not have gotten bytes: $bytes");
+      }).catchError((e) {
+        error = e;
+      }).then((_) {
+        expect(error is UnderflowError, isTrue,
+            reason: "!UnderflowError: $error");
+      });
+      new Stream.fromIterable([1, 2, 3]).pipe(buf);
+      return future;
+    });
+  });
+}