Add concurrent modification check to ListMixin/IterableMixin.reduce.

tests/corelib/iterable_fold_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 "package:expect/expect.dart";
+import 'dart:collection';
+import 'dart:typed_data';
+
+class MyList extends ListBase {
+  List list;
+  MyList(this.list);
+
+  get length => list.length;
+  set length(val) { list.length = val; }
+
+  operator [](index) => list[index];
+  operator []=(index, val) => list[index] = val;
+}
+
+id(x) => x;
+
+main() {
+  for (var iterable in [
+      const [1, 2, 3],
+      [1, 2, 3],
+      new List(3)..[0] = 1..[1] = 2..[2] = 3,
+      {1: 1, 2: 2, 3: 3}.keys,
+      {1: 1, 2: 2, 3: 3}.values,
+      new Iterable.generate(3, (x) => x + 1),
+      new List.generate(3, (x) => x + 1),
+      [0, 1, 2, 3].where((x) => x > 0),
+      [0, 1, 2].map((x) => x + 1),
+      [[1, 2], [3]].expand(id),
+      [3, 2, 1].reversed,
+      [0, 1, 2, 3].skip(1),
+      [1, 2, 3, 4].take(3),
+      new Uint8List(3)..[0] = 1..[1] = 2..[2] = 3,
+      (new HashMap()..[1] = 1..[2] = 2..[3] = 3).keys,
+      (new HashMap()..[1] = 1..[2] = 2..[3] = 3).values,
+      (new SplayTreeMap()..[1] = 0..[2] = 0..[3] = 0).keys,
+      (new SplayTreeMap()..[0] = 1..[1] = 2..[2] = 3).values,
+      new HashSet()..add(1)..add(2)..add(3),
+      new LinkedHashSet()..add(1)..add(2)..add(3),
+      new SplayTreeSet()..add(1)..add(2)..add(3),
+      "\x01\x02\x03".codeUnits,
+      "\x01\x02\x03".runes,
+      new MyList([1, 2, 3]),
+    ]) {
+    int callCount = 0;
+    var result = iterable.fold(0, (x, y) { callCount++;  return x + y; });
+    Expect.equals(6, result, "${iterable.runtimeType}");
+    Expect.equals(3, callCount);
+  }
+
+  // Empty iterables are allowed.
+  for (var iterable in [
+      const [],
+      [],
+      new List(0),
+      {}.keys,
+      {}.values,
+      new Iterable.generate(0, (x) => x + 1),
+      new List.generate(0, (x) => x + 1),
+      [0, 1, 2, 3].where((x) => false),
+      [].map((x) => x + 1),
+      [[], []].expand(id),
+      [].reversed,
+      [0, 1, 2, 3].skip(4),
+      [1, 2, 3, 4].take(0),
+      new Uint8List(0),
+      (new HashMap()).keys,
+      (new HashMap()).values,
+      (new SplayTreeMap()).keys,
+      (new SplayTreeMap()).values,
+      new HashSet(),
+      new LinkedHashSet(),
+      new SplayTreeSet(),
+      "".codeUnits,
+      "".runes,
+      new MyList([]),
+    ]) {
+    Expect.equals(42, iterable.fold(42, (x, y) => throw "Unreachable"));
+  }
+
+  // Singleton iterables are calling reduce function.
+  for (var iterable in [
+      const [1],
+      [1],
+      new List(1)..[0] = 1,
+      {1: 1}.keys,
+      {1: 1}.values,
+      new Iterable.generate(1, (x) => x + 1),
+      new List.generate(1, (x) => x + 1),
+      [0, 1, 2, 3].where((x) => x == 1),
+      [0].map((x) => x + 1),
+      [[], [1]].expand(id),
+      [1].reversed,
+      [0, 1].skip(1),
+      [1, 2, 3, 4].take(1),
+      new Uint8List(1)..[0] = 1,
+      (new HashMap()..[1] = 0).keys,
+      (new HashMap()..[0] = 1).values,
+      (new SplayTreeMap()..[1] = 0).keys,
+      (new SplayTreeMap()..[0] = 1).values,
+      new HashSet()..add(1),
+      new LinkedHashSet()..add(1),
+      new SplayTreeSet()..add(1),
+      "\x01".codeUnits,
+      "\x01".runes,
+      new MyList([1]),
+    ]) {
+    Expect.equals(43, iterable.fold(42, (x, y) => x + y));
+  }
+
+  // Concurrent modifications not allowed.
+  testModification(base, modify, transform) {
+    var iterable = transform(base);
+    Expect.throws(() {
+      iterable.fold(0, (x, y) {
+        modify(base);
+        return x + y;
+      });
+    }, (e) => e is ConcurrentModificationError);
+  }
+
+  void add4(collection) { collection.add(4); }
+  void put4(map) { map[4] = 4; }
+
+  testModification([1, 2, 3], add4, id);
+  testModification(new HashSet()..add(1)..add(2)..add(3), add4, id);
+  testModification(new LinkedHashSet()..add(1)..add(2)..add(3), add4, id);
+  testModification(new SplayTreeSet()..add(1)..add(2)..add(3), add4, id);
+  testModification(new MyList([1, 2, 3]), add4, id);
+
+  testModification([0, 1, 2, 3], add4, (x) => x.where((x) => x > 0));
+  testModification([0, 1, 2], add4, (x) => x.map((x) => x + 1));
+  testModification([[1, 2], [3]], add4, (x) => x.expand((x) => x));
+  testModification([3, 2, 1], add4, (x) => x.reversed);
+  testModification({1: 1, 2: 2, 3: 3}, put4, (x) => x.keys);
+  testModification({1: 1, 2: 2, 3: 3}, put4, (x) => x.values);
+  var hashMap = new HashMap()..[1] = 1..[2] = 2..[3] = 3;
+  testModification(hashMap, put4, (x) => x.keys);
+  hashMap = new HashMap()..[1] = 1..[2] = 2..[3] = 3;
+  testModification(hashMap, put4, (x) => x.values);
+  var splayMap = new SplayTreeMap()..[1] = 1..[2] = 2..[3] = 3;
+  testModification(splayMap, put4, (x) => x.keys);
+  splayMap = new SplayTreeMap()..[1] = 1..[2] = 2..[3] = 3;
+  testModification(splayMap, put4, (x) => x.values);
+}