Add Map constructors taking iterables.

tests/corelib/map_from_iterable_test.dart

+// Copyright (c) 2011, 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';
+
+main() {
+  defaultFunctionValuesTest();
+  defaultKeyFunctionTest();
+  defaultValueFunctionTest();
+  noDefaultValuesTest();
+  emptyIterableTest();
+  equalElementsTest();
+  genericTypeTest();
+}
+
+void defaultFunctionValuesTest() {
+  var map = new Map.fromIterable([1, 2, 3]);
+
+  Expect.isTrue(map is Map);
+  Expect.isTrue(map is HashMap);
+
+  Expect.equals(3, map.length);
+  Expect.equals(3, map.keys.length);
+  Expect.equals(3, map.values.length);
+
+  Expect.equals(1, map[1]);
+  Expect.equals(2, map[2]);
+  Expect.equals(3, map[3]);
+}
+
+void defaultKeyFunctionTest() {
+  var map = new Map.fromIterable([1, 2, 3], value: (x) => x + 1);
+
+  Expect.isTrue(map is Map);
+  Expect.isTrue(map is HashMap);
+
+  Expect.equals(3, map.length);
+  Expect.equals(3, map.keys.length);
+  Expect.equals(3, map.values.length);
+
+  Expect.equals(2, map[1]);
+  Expect.equals(3, map[2]);
+  Expect.equals(4, map[3]);
+}
+
+void defaultValueFunctionTest() {
+  var map = new Map.fromIterable([1, 2, 3], key: (x) => x + 1);
+
+  Expect.isTrue(map is Map);
+  Expect.isTrue(map is HashMap);
+
+  Expect.equals(3, map.length);
+  Expect.equals(3, map.keys.length);
+  Expect.equals(3, map.values.length);
+
+  Expect.equals(1, map[2]);
+  Expect.equals(2, map[3]);
+  Expect.equals(3, map[4]);
+}
+
+void noDefaultValuesTest() {
+  var map = new Map.fromIterable([1, 2, 3],
+      key: (x) => x + 1, value: (x) => x - 1);
+
+
+  Expect.isTrue(map is Map);
+  Expect.isTrue(map is HashMap);
+
+  Expect.equals(3, map.length);
+  Expect.equals(3, map.keys.length);
+  Expect.equals(3, map.values.length);
+
+  Expect.equals(0, map[2]);
+  Expect.equals(1, map[3]);
+  Expect.equals(2, map[4]);
+}
+
+void emptyIterableTest() {
+  var map = new Map.fromIterable([]);
+  Expect.isTrue(map is Map);
+  Expect.isTrue(map is HashMap);
+
+  Expect.equals(0, map.length);
+  Expect.equals(0, map.keys.length);
+  Expect.equals(0, map.values.length);
+}
+
+void equalElementsTest() {
+  var map = new Map.fromIterable([1, 2, 2], key: (x) => x + 1);
+
+  Expect.isTrue(map is Map);
+  Expect.isTrue(map is HashMap);
+
+  Expect.equals(2, map.length);
+  Expect.equals(2, map.keys.length);
+  Expect.equals(2, map.values.length);
+
+  Expect.equals(1, map[2]);
+  Expect.equals(2, map[3]);
+}
+
+void genericTypeTest() {
+  var map = new Map<int, String>.fromIterable([1, 2, 3], value: (x) => '$x');
+  Expect.isTrue(map is Map<int, String>);
+
+  // Make sure it is not just Map<dynamic, dynamic>.
+  Expect.isFalse(map is Map<String, dynamic>);
+  Expect.isFalse(map is Map<dynamic, int>);
+}
+