extract ReplacementRange for use in tests

pkg/analysis_server/test/services/completion/dart/completion_contributor_util.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.completion.dart.util;
 
 import 'dart:async';
 
 import 'package:analysis_server/plugin/protocol/protocol.dart' as protocol
     show Element, ElementKind;
 import 'package:analysis_server/plugin/protocol/protocol.dart'
     hide Element, ElementKind;
 import 'package:analysis_server/plugin/protocol/protocol.dart';
 import 'package:analysis_server/src/provisional/completion/dart/completion_dart.dart';
 import 'package:analysis_server/src/services/completion/completion_core.dart';
 import 'package:analysis_server/src/services/completion/dart/completion_manager.dart'
     show DartCompletionRequestImpl;
 import 'package:analysis_server/src/services/completion/dart_completion_manager.dart'
-    show DART_RELEVANCE_DEFAULT, DART_RELEVANCE_LOW;
+    show DART_RELEVANCE_DEFAULT, DART_RELEVANCE_LOW, ReplacementRange;
 import 'package:analysis_server/src/services/index/index.dart';
 import 'package:analysis_server/src/services/index/local_memory_index.dart';
 import 'package:analysis_server/src/services/search/search_engine_internal.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:unittest/unittest.dart';
 
 import '../../../abstract_context.dart';
 
 int suggestionComparator(CompletionSuggestion s1, CompletionSuggestion s2) {
   String c1 = s1.completion.toLowerCase();
   String c2 = s2.completion.toLowerCase();
   return c1.compareTo(c2);
 }
 
 abstract class DartCompletionContributorTest extends AbstractContextTest {
   Index index;
   SearchEngineImpl searchEngine;
   String testFile = '/completionTest.dart';
   Source testSource;
   int completionOffset;
+  int replacementOffset;
+  int replacementLength;
   DartCompletionContributor contributor;
   DartCompletionRequest request;
   List<CompletionSuggestion> suggestions;
 
   void addTestSource(String content) {
     expect(completionOffset, isNull, reason: 'Call addTestUnit exactly once');
     completionOffset = content.indexOf('^');
     expect(completionOffset, isNot(equals(-1)), reason: 'missing ^');
     int nextOffset = content.indexOf('^', completionOffset + 1);
     expect(nextOffset, equals(-1), reason: 'too many ^');
@@ skipping 92 matching lines @@
     // would therefore not wait for microtask callbacks that are scheduled after
     // invoking this method.
     return new Future.delayed(
         Duration.ZERO, () => computeLibrariesContaining(times - 1));
   }
 
   Future computeSuggestions([int times = 200]) async {
     CompletionRequestImpl baseRequest = new CompletionRequestImpl(
         context, provider, searchEngine, testSource, completionOffset);
     request = new DartCompletionRequestImpl.forRequest(baseRequest);
+    var range = new ReplacementRange.compute(request.offset, request.target);
+    replacementOffset = range.offset;
+    replacementLength = range.length;
     Completer<List<CompletionSuggestion>> completer =
         new Completer<List<CompletionSuggestion>>();
 
     // Request completions
     contributor
         .computeSuggestions(request)
         .then((List<CompletionSuggestion> computedSuggestions) {
       completer.complete(computedSuggestions);
     });
 
@@ skipping 62 matching lines @@
   }
 
   @override
   void setUp() {
     super.setUp();
     index = createLocalMemoryIndex();
     searchEngine = new SearchEngineImpl(index);
     contributor = createContributor();
   }
 }