test rename overhaul: step 7 - corelib tests

tests/corelib/src/StringSubstringTest.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.
-
-main() {
-  // Test that not providing an optional argument goes to the end.
-  Expect.equals("".substring(0), "");
-  Expect.throws(() => "".substring(1),
-      (e) => e is IndexOutOfRangeException);
-  Expect.throws(() => "".substring(-1),
-      (e) => e is IndexOutOfRangeException);
-
-  Expect.equals("abc".substring(0), "abc");
-  Expect.equals("abc".substring(1), "bc");
-  Expect.equals("abc".substring(2), "c");
-  Expect.equals("abc".substring(3), "");
-  Expect.throws(() => "abc".substring(4),
-      (e) => e is IndexOutOfRangeException);
-  Expect.throws(() => "abc".substring(-1),
-      (e) => e is IndexOutOfRangeException);
-
-  // Test that providing null goes to the end.
-  Expect.equals("".substring(0, null), "");
-  Expect.throws(() => "".substring(1, null),
-      (e) => e is IndexOutOfRangeException);
-  Expect.throws(() => "".substring(-1, null),
-      (e) => e is IndexOutOfRangeException);
-
-  Expect.equals("abc".substring(0, null), "abc");
-  Expect.equals("abc".substring(1, null), "bc");
-  Expect.equals("abc".substring(2, null), "c");
-  Expect.equals("abc".substring(3, null), "");
-  Expect.throws(() => "abc".substring(4, null),
-      (e) => e is IndexOutOfRangeException);
-  Expect.throws(() => "abc".substring(-1, null),
-      (e) => e is IndexOutOfRangeException);
-}