Add List.insert.

tests/corelib/list_insert_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.
+
+void main() {
+  // Normal modifiable list.
+  var l1 = [0, 1, 2, 3, 4];
+
+  bool checkedMode = false;
+  assert(checkedMode = true);
+
+  // Index must be integer and in range.
+  Expect.throws(() { l1.insert(-1, 5); },
+                (e) => e is RangeError,
+                "negative");
+  Expect.throws(() { l1.insert(6, 5); },
+                (e) => e is RangeError,
+                "too large");
+  Expect.throws(() { l1.insert(null, 5); });
+  Expect.throws(() { l1.insert("1", 5); });
+  Expect.throws(() { l1.insert(1.5, 5); });
+
+  l1.insert(5, 5);
+  Expect.equals(6, l1.length);
+  Expect.equals(5, l1[5]);
+  Expect.equals("[0, 1, 2, 3, 4, 5]", l1.toString());
+
+  l1.insert(0, -1);
+  Expect.equals(7, l1.length);
+  Expect.equals(-1, l1[0]);
+  Expect.equals("[-1, 0, 1, 2, 3, 4, 5]", l1.toString());
+
+  // Fixed size list.
+  var l2 = new List(5);
+  for (var i = 0; i < 5; i++) l2[i] = i;
+  Expect.throws(() { l2.insert(2, 5); },
+                (e) => e is UnsupportedError,
+                "fixed-length");
+
+  // Unmodifiable list.
+  var l3 = const [0, 1, 2, 3, 4];
+  Expect.throws(() { l3.insert(2, 5); },
+                (e) => e is UnsupportedError,
+                "unmodifiable");
+
+  // Empty list is not special.
+  var l4 = [];
+  l4.insert(0, 499);
+  Expect.equals(1, l4.length);
+  Expect.equals(499, l4[0]);
+}