Switch analysis_server to use 'package:test'.

pkg/analysis_server/test/services/correction/strings_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.
 
 library test.services.correction.strings;
 
 import 'package:analysis_server/src/services/correction/strings.dart';
+import 'package:test/test.dart' hide isEmpty;
 import 'package:test_reflective_loader/test_reflective_loader.dart';
-import 'package:unittest/unittest.dart' hide isEmpty;
 
 import '../../utils.dart';
 
 main() {
   initializeTestEnvironment();
-  defineReflectiveTests(StringsTest);
+  defineReflectiveSuite(() {
+    defineReflectiveTests(StringsTest);
+  });
 }
 
 @reflectiveTest
 class StringsTest {
   void test_capitalize() {
     expect(capitalize(''), '');
     expect(capitalize('a'), 'A');
     expect(capitalize('abc'), 'Abc');
     expect(capitalize('abc def'), 'Abc def');
     expect(capitalize('ABC'), 'ABC');
@@ skipping 10 matching lines @@
   void test_computeSimpleDiff() {
     assertDiff(String oldStr, String newStr) {
       SimpleDiff diff = computeSimpleDiff(oldStr, newStr);
       expect(diff.offset, isNonNegative);
       expect(diff.length, isNonNegative);
       String applied = oldStr.substring(0, diff.offset) +
           diff.replacement +
           oldStr.substring(diff.offset + diff.length);
       expect(applied, newStr);
     }
+
     assertDiff('', '');
     assertDiff('', 'a');
     assertDiff('abc', '');
     assertDiff('abcd', 'acd');
     assertDiff('a', 'b');
     assertDiff('12345xyz', '12345abcxyz');
     assertDiff('12345xyz', '12345xyzabc');
     assertDiff('abbc', 'abbbc');
     assertDiff('abbbbc', 'abbbbbbc');
   }
@@ skipping 143 matching lines @@
     expect(repeat('abc', 3), 'abcabcabc');
   }
 
   void test_substringAfterLast() {
     expect(substringAfterLast('', '/'), '');
     expect(substringAfterLast('abc', ''), '');
     expect(substringAfterLast('abc', 'd'), 'abc');
     expect(substringAfterLast('abcbde', 'b'), 'de');
   }
 }