Add a ScheduledStream class and some stream matchers.

pkg/scheduled_test/test/scheduled_stream/stream_matcher_test.dart

+// Copyright (c) 2013, 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 scheduled_test.stream_matcher_test;
+
+import 'dart:async';
+
+import 'package:scheduled_test/scheduled_stream.dart';
+import 'package:scheduled_test/scheduled_test.dart';
+import 'package:scheduled_test/src/utils.dart';
+
+import '../metatest.dart';
+import '../utils.dart';
+
+/// Returns a [ScheduledStream] that asynchronously emits the numbers 1 through
+/// 5 and then closes.
+ScheduledStream createStream() {
+  var controller = new StreamController();
+  var stream = new ScheduledStream(controller.stream);
+
+  var future = pumpEventQueue();
+  for (var i = 1; i <= 5; i++) {
+    future = future.then((_) {
+      controller.add(i);
+      return pumpEventQueue();
+    });
+  }
+  future.then((_) => controller.close());
+
+  return stream;
+}
+
+void main(_, message) {
+  initMetatest(message);
+
+  setUpTimeout();
+
+  expectTestPasses("expect() with matching values passes", () {
+    var stream = createStream();
+    stream.expect(1);
+    stream.expect(2);
+    stream.expect(3);
+    stream.expect(4);
+    stream.expect(5);
+  });
+
+  expectTestFails("expect() with a non-matching value fails", () {
+    var stream = createStream();
+    stream.expect(1);
+    stream.expect(2);
+    stream.expect(100);
+  }, (errors) {
+    expect(errors, hasLength(1));
+    expect(errors.first.error.message, equals(
+        "Expected: <100>\n"
+        " Emitted: * 1\n"
+        "          * 2\n"
+        "          * 3"));
+  });
+
+  expectTestFails("expect() with too few values fails", () {
+    var stream = createStream();
+    stream.expect(1);
+    stream.expect(2);
+    stream.expect(3);
+    stream.expect(4);
+    stream.expect(5);
+    stream.expect(6);
+  }, (errors) {
+    expect(errors, hasLength(1));
+    expect(errors.first.error.message, equals(
+        "Expected: <6>\n"
+        " Emitted: * 1\n"
+        "          * 2\n"
+        "          * 3\n"
+        "          * 4\n"
+        "          * 5\n"
+        "   Which: unexpected end of stream"));
+  });
+
+  expectTestPasses("expect() with matching matcher passes", () {
+    var stream = createStream();
+    stream.expect(greaterThan(0));
+    stream.expect(greaterThan(1));
+    stream.expect(greaterThan(2));
+    stream.expect(greaterThan(3));
+    stream.expect(greaterThan(4));
+  });
+
+  expectTestFails("expect() with a non-matching matcher fails", () {
+    var stream = createStream();
+    stream.expect(greaterThan(0));
+    stream.expect(greaterThan(1));
+    stream.expect(greaterThan(100));
+  }, (errors) {
+    expect(errors, hasLength(1));
+    expect(errors.first.error.message, equals(
+        "Expected: a value greater than <100>\n"
+        " Emitted: * 1\n"
+        "          * 2\n"
+        "          * 3\n"
+        "   Which: is not a value greater than <100>"));
+  });
+
+  expectTestPasses("nextValues() with matching values succeeds", () {
+    createStream().expect(nextValues(3, unorderedEquals([3, 2, 1])));
+  });
+
+  expectTestFails("nextValues() without enough values fails", () {
+    createStream().expect(nextValues(6, unorderedEquals([3, 2, 1])));
+  }, (errors) {
+    expect(errors, hasLength(1));
+    expect(errors.first.error.message, equals(
+        "Expected: 6 values that equals [3, 2, 1] unordered\n"
+        " Emitted: * 1\n"
+        "          * 2\n"
+        "          * 3\n"
+        "          * 4\n"
+        "          * 5\n"
+        "   Which: unexpected end of stream"));
+  });
+
+  expectTestFails("nextValues() with non-matching values fails", () {
+    createStream().expect(nextValues(3, unorderedEquals([2, 3, 4])));
+  }, (errors) {
+    expect(errors, hasLength(1));
+    expect(errors.first.error.message, equals(
+        "Expected: 3 values that equals [2, 3, 4] unordered\n"
+        " Emitted: * 1\n"
+        "          * 2\n"
+        "          * 3\n"
+        "   Which: has no match for element <4> at index 2"));
+  });
+
+  expectTestPasses("inOrder() with several values matches and consumes those "
+      "values", () {
+    var stream = createStream();
+    stream.expect(inOrder([1, 2, 3, 4]));
+    stream.expect(5);
+  });
+
+  expectTestPasses("inOrder() with several stream matchers matches them", () {
+    createStream().expect(inOrder([
+      consumeThrough(3),
+      nextValues(2, unorderedEquals([5, 4]))
+    ]));
+  });
+
+  expectTestPasses("inOrder() with no values succeeds and consumes nothing",
+      () {
+    var stream = createStream();
+    stream.expect(inOrder([]));
+    stream.expect(1);
+  });
+
+  expectTestFails("inOrder() fails if a sub-matcher fails", () {
+    createStream().expect(inOrder([
+      nextValues(3, unorderedEquals([2, 3, 4])),
+      consumeThrough(5)
+    ]));
+  }, (errors) {
+    expect(errors, hasLength(1));
+    expect(errors.first.error.message, equals(
+        "Expected: * 3 values that equals [2, 3, 4] unordered\n"
+        "        | * values followed by <5>\n"
+        " Emitted: * 1\n"
+        "          * 2\n"
+        "          * 3\n"
+        "   Which: matcher #1 failed:\n"
+        "        | has no match for element <4> at index 2"));
+  });
+
+  expectTestFails("inOrder() with one value has a simpler description", () {
+    createStream().expect(inOrder([100]));
+  }, (errors) {
+    expect(errors, hasLength(1));
+    expect(errors.first.error.message, equals(
+        "Expected: <100>\n"
+        " Emitted: * 1"));
+  });
+
+  expectTestPasses("consumeThrough() consumes values through the given matcher",
+      () {
+    var stream = createStream();
+    stream.expect(consumeThrough(greaterThan(2)));
+    stream.expect(4);
+  });
+
+  expectTestPasses("consumeThrough() will stop if the first value matches", () {
+    var stream = createStream();
+    stream.expect(consumeThrough(1));
+    stream.expect(2);
+  });
+
+  expectTestFails("consumeThrough() will fail if the stream ends before the "
+      "value is reached", () {
+    createStream().expect(consumeThrough(100));
+  }, (errors) {
+    expect(errors, hasLength(1));
+    expect(errors.first.error.message, equals(
+        "Expected: values followed by <100>\n"
+        " Emitted: * 1\n"
+        "          * 2\n"
+        "          * 3\n"
+        "          * 4\n"
+        "          * 5\n"
+        "   Which: unexpected end of stream"));
+  });
+
+  expectTestPasses("either() will match if the first branch matches", () {
+    createStream().expect(either(1, 100));
+  });
+
+  expectTestPasses("either() will match if the second branch matches", () {
+    createStream().expect(either(100, 1));
+  });
+
+  expectTestPasses("either() will consume the maximal number of values if both "
+      "branches match", () {
+    // First branch consumes more.
+    var stream = createStream();
+    stream.expect(either(inOrder([1, 2, 3]), 1));
+    stream.expect(4);
+
+    // Second branch consumes more.
+    stream = createStream();
+    stream.expect(either(1, inOrder([1, 2, 3])));
+    stream.expect(4);
+  });
+
+  expectTestFails("either() will fail if neither branch matches", () {
+    createStream().expect(either(
+        inOrder([3, 2, 1]),
+        nextValues(4, unorderedEquals([5, 4, 3, 2]))));
+  }, (errors) {
+    expect(errors, hasLength(1));
+    expect(errors.first.error.message, equals(
+        "Expected: either\n"
+        "        |   * <3>\n"
+        "        |   * <2>\n"
+        "        |   * <1>\n"
+        "        | or\n"
+        "        |   4 values that equals [5, 4, 3, 2] unordered\n"
+        " Emitted: * 1\n"
+        "          * 2\n"
+        "          * 3\n"
+        "          * 4\n"
+        "   Which: both\n"
+        "        |   matcher #1 failed\n"
+        "        | and\n"
+        "        |   has no match for element <5> at index 0"));
+  });
+
+  expectTestPasses("allow() consumes the matcher if it matches", () {
+    var stream = createStream();
+    stream.expect(allow(inOrder([1, 2, 3])));
+    stream.expect(4);
+  });
+
+  expectTestPasses("allow() consumes nothing if the matcher doesn't match", () {
+    var stream = createStream();
+    stream.expect(allow(inOrder([1, 2, 100])));
+    stream.expect(1);
+  });
+
+  expectTestPasses("isDone succeeds at the end of the stream", () {
+    var stream = createStream();
+    stream.expect(consumeThrough(5));
+    stream.expect(isDone);
+  });
+
+  expectTestFails("isDone fails before the end of the stream", () {
+    var stream = createStream();
+    stream.expect(consumeThrough(4));
+    stream.expect(isDone);
+  }, (errors) {
+    expect(errors, hasLength(1));
+    expect(errors.first.error.message, equals(
+        "Expected: is done\n"
+        " Emitted: * 1\n"
+        "          * 2\n"
+        "          * 3\n"
+        "          * 4\n"
+        "          * 5\n"
+        "   Which: stream wasn't finished"));
+  });
+}