Refactor removeRange.

tests/corelib/list_remove_range_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";
 
 main() {
   var list = [];
   list.removeRange(0, 0);
   Expect.equals(0, list.length);
@@ skipping 10 matching lines @@
 
   list.removeRange(0, 1);
   Expect.equals(0, list.length);
 
   list.addAll([3, 4, 5, 6]);
   Expect.equals(4, list.length);
   list.removeRange(0, 4);
   Expect.listEquals([], list);
 
   list.addAll([3, 4, 5, 6]);
-  list.removeRange(2, 2);
+  list.removeRange(2, 4);
   Expect.listEquals([3, 4], list);
   list.addAll([5, 6]);
 
-  expectIOORE(() { list.removeRange(4, 1); });
+  expectIOORE(() { list.removeRange(4, 5); });
   Expect.listEquals([3, 4, 5, 6], list);
 
-  list.removeRange(1, 2);
+  list.removeRange(1, 3);
   Expect.listEquals([3, 6], list);
 
   testNegativeIndices();
 }
 
 void expectIOORE(Function f) {
   Expect.throws(f, (e) => e is RangeError);
 }
 
 void testNegativeIndices() {
   var list = [1, 2];
   expectIOORE(() { list.removeRange(-1, 1); });
   Expect.listEquals([1, 2], list);
 
   // A negative length throws an ArgumentError.
-  Expect.throws(() { list.removeRange(0, -1); },
-      (e) => e is ArgumentError);
+  expectIOORE(() { list.removeRange(0, -1); });
   Expect.listEquals([1, 2], list);
 
-  Expect.throws(() { list.removeRange(-1, -1); },
-      (e) => e is ArgumentError);
+  expectIOORE(() { list.removeRange(-1, -1); });
   Expect.listEquals([1, 2], list);
 
-  // A zero length prevails, and does not throw an exception.
-  list.removeRange(-1, 0);
-  Expect.listEquals([1, 2], list);
+  expectIOORE(() { list.removeRange(-1, 0); });
 
-  list.removeRange(4, 0);
+  expectIOORE(() { list.removeRange(4, 4); });
   Expect.listEquals([1, 2], list);
 }