remove duplicate completion suggestions

pkg/analysis_server/lib/src/services/completion/local_computer.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 services.completion.computer.dart.local;
 
 import 'dart:async';
+import 'dart:collection';
 
 import 'package:analysis_server/src/protocol.dart' as protocol
     show Element, ElementKind;
 import 'package:analysis_server/src/protocol.dart' hide Element, ElementKind;
 import 'package:analysis_server/src/services/completion/dart_completion_manager.dart';
 import 'package:analysis_server/src/services/completion/local_declaration_visitor.dart';
 import 'package:analysis_server/src/services/completion/optype.dart';
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/scanner.dart';
 import 'package:analyzer/src/generated/utilities_dart.dart';
@@ skipping 403 matching lines @@
   }
 }
 
 /**
  * A visitor for collecting suggestions from the most specific child [AstNode]
  * that contains the completion offset to the [CompilationUnit].
  */
 class _LocalVisitor extends LocalDeclarationVisitor {
   final DartCompletionRequest request;
   final OpType optype;
+  HashSet<String> completions = new HashSet();
 
   _LocalVisitor(this.request, int offset, this.optype) : super(offset);
 
   @override
   void declaredClass(ClassDeclaration declaration) {
     if (optype.includeTypeNameSuggestions) {
       bool isDeprecated = _isDeprecated(declaration);
       CompletionSuggestion suggestion = _addSuggestion(declaration.name,
           _NO_RETURN_TYPE, isDeprecated, DART_RELEVANCE_DEFAULT);
       if (suggestion != null) {
@@ skipping 218 matching lines @@
     suggestion.requiredParameterCount = paramList.where(
         (FormalParameter param) => param is! DefaultFormalParameter).length;
     suggestion.hasNamedParameters = paramList
         .any((FormalParameter param) => param.kind == ParameterKind.NAMED);
   }
 
   CompletionSuggestion _addSuggestion(SimpleIdentifier id, TypeName returnType,
       bool isDeprecated, int defaultRelevance, {ClassDeclaration classDecl}) {
     if (id != null) {
       String completion = id.name;
-      if (completion != null && completion.length > 0 && completion != '_') {
+      if (completion != null &&
+          completion.length > 0 &&
+          completion != '_' &&
+          completions.add(completion)) {
         CompletionSuggestion suggestion = new CompletionSuggestion(
             CompletionSuggestionKind.INVOCATION,
             isDeprecated ? DART_RELEVANCE_LOW : defaultRelevance, completion,
             completion.length, 0, isDeprecated, false,
             returnType: _nameForType(returnType));
         if (classDecl != null) {
           SimpleIdentifier identifier = classDecl.name;
           if (identifier != null) {
             String name = identifier.name;
             if (name != null && name.length > 0) {
@@ skipping 11 matching lines @@
   bool _isVoid(TypeName returnType) {
     if (returnType != null) {
       Identifier id = returnType.name;
       if (id != null && id.name == 'void') {
         return true;
       }
     }
     return false;
   }
 }