remove duplicate suggestions

pkg/analysis_server/test/domain_completion_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.domain.completion;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/constants.dart';
 import 'package:analysis_server/src/domain_completion.dart';
@@ skipping 28 matching lines @@
     int nextOffset = content.indexOf('^', completionOffset + 1);
     expect(nextOffset, equals(-1), reason: 'too many ^');
     return super.addTestFile(
         content.substring(0, completionOffset)
         + content.substring(completionOffset + 1));
   }
 
   void assertHasResult(CompletionSuggestionKind kind, String completion,
       [CompletionRelevance relevance = CompletionRelevance.DEFAULT,
       bool isDeprecated = false, bool isPotential = false]) {
-    var cs = suggestions.firstWhere((cs) => cs.completion == completion, orElse: () {
+    var cs;
+    suggestions.forEach((s) {
+      if (s.completion == completion) {
+        if (cs == null) {
+          cs = s;
+        } else {
+          fail('expected exactly one $completion but found > 1');
+        }
+      }
+    });
+    if (cs == null) {
       var completions = suggestions.map((s) => s.completion).toList();
       fail('expected "$completion" but found\n $completions');
-    });
+    }
     expect(cs.kind, equals(kind));
     expect(cs.relevance, equals(relevance));
     expect(cs.selectionOffset, equals(completion.length));
     expect(cs.selectionLength, equals(0));
     expect(cs.isDeprecated, equals(isDeprecated));
     expect(cs.isPotential, equals(isPotential));
   }
 
   void assertNoResult(String completion) {
     if (suggestions.any((cs) => cs.completion == completion)) {
@@ skipping 28 matching lines @@
   void processNotification(Notification notification) {
     if (notification.event == COMPLETION_RESULTS) {
       String id = notification.getParameter(ID);
       assertValidId(id);
       if (id == completionId) {
         expect(suggestionsDone, isFalse);
         replacementOffset = notification.getParameter(REPLACEMENT_OFFSET);
         replacementLength = notification.getParameter(REPLACEMENT_LENGTH);
         suggestionsDone = notification.getParameter(LAST);
         expect(suggestionsDone, isNotNull);
+        suggestions = [];
         for (Map<String, Object> json in notification.getParameter(RESULTS)) {
           expect(json, isNotNull);
           suggestions.add(new CompletionSuggestion.fromJson(json));
         }
       }
     }
   }
 
   @override
   void setUp() {
@@ skipping 63 matching lines @@
     ''');
     return getSuggestions().then((_) {
 //      expect(replacementOffset, equals(completionOffset - 3));
 //      expect(replacementLength, equals(4));
       assertHasResult(CompletionSuggestionKind.CLASS, 'Object');
       assertHasResult(CompletionSuggestionKind.TOP_LEVEL_VARIABLE, 'test');
       assertNoResult('HtmlElement');
     });
   }
 }