Import analysis_services.dart into analysis_server.dart.

pkg/analysis_services/lib/src/correction/assist.dart

Index: pkg/analysis_services/lib/src/correction/assist.dart
diff --git a/pkg/analysis_services/lib/src/correction/assist.dart b/pkg/analysis_services/lib/src/correction/assist.dart
deleted file mode 100644
index 9415683c1c75cdfd3dcbce2aa323224c860f2d35..0000000000000000000000000000000000000000
--- a/pkg/analysis_services/lib/src/correction/assist.dart
+++ /dev/null
@@ -1,1589 +0,0 @@
-// 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.src.correction.assist;
-
-import 'dart:collection';
-
-import 'package:analysis_services/correction/assist.dart';
-import 'package:analysis_services/correction/change.dart';
-import 'package:analysis_services/search/hierarchy.dart';
-import 'package:analysis_services/search/search_engine.dart';
-import 'package:analysis_services/src/correction/name_suggestion.dart';
-import 'package:analysis_services/src/correction/source_buffer.dart';
-import 'package:analysis_services/src/correction/source_range.dart';
-import 'package:analysis_services/src/correction/statement_analyzer.dart';
-import 'package:analysis_services/src/correction/util.dart';
-import 'package:analyzer/src/generated/ast.dart';
-import 'package:analyzer/src/generated/element.dart';
-import 'package:analyzer/src/generated/java_core.dart';
-import 'package:analyzer/src/generated/scanner.dart';
-import 'package:analyzer/src/generated/source.dart';
-import 'package:path/path.dart';
-
-
-
-typedef _SimpleIdentifierVisitor(SimpleIdentifier node);
-
-
-/**
- * The computer for Dart assists.
- */
-class AssistProcessor {
-  final SearchEngine searchEngine;
-  final Source source;
-  final String file;
-  final CompilationUnit unit;
-  final int selectionOffset;
-  final int selectionLength;
-  CompilationUnitElement unitElement;
-  LibraryElement unitLibraryElement;
-  String unitLibraryFile;
-  String unitLibraryFolder;
-
-  final List<Edit> edits = <Edit>[];
-  final Map<String, LinkedEditGroup> linkedPositionGroups = <String,
-      LinkedEditGroup>{};
-  Position exitPosition = null;
-  final List<Assist> assists = <Assist>[];
-
-  int selectionEnd;
-  CorrectionUtils utils;
-  AstNode node;
-
-  AssistProcessor(this.searchEngine, this.source, this.file, this.unit,
-      this.selectionOffset, this.selectionLength) {
-    unitElement = unit.element;
-    unitLibraryElement = unitElement.library;
-    unitLibraryFile = unitLibraryElement.source.fullName;
-    unitLibraryFolder = dirname(unitLibraryFile);
-    selectionEnd = selectionOffset + selectionLength;
-  }
-
-  /**
-   * Returns the EOL to use for this [CompilationUnit].
-   */
-  String get eol => utils.endOfLine;
-
-  List<Assist> compute() {
-    utils = new CorrectionUtils(unit);
-    node = new NodeLocator.con2(
-        selectionOffset,
-        selectionEnd).searchWithin(unit);
-    // try to add proposals
-    _addProposal_addTypeAnnotation();
-    _addProposal_assignToLocalVariable();
-    _addProposal_convertToBlockFunctionBody();
-    _addProposal_convertToExpressionFunctionBody();
-    _addProposal_convertToIsNot_onIs();
-    _addProposal_convertToIsNot_onNot();
-    _addProposal_convertToIsNotEmpty();
-    _addProposal_exchangeOperands();
-    _addProposal_importAddShow();
-    _addProposal_invertIf();
-    _addProposal_joinIfStatementInner();
-    _addProposal_joinIfStatementOuter();
-    _addProposal_joinVariableDeclaration_onAssignment();
-    _addProposal_joinVariableDeclaration_onDeclaration();
-    _addProposal_removeTypeAnnotation();
-    _addProposal_replaceConditionalWithIfElse();
-    _addProposal_replaceIfElseWithConditional();
-    _addProposal_splitAndCondition();
-    _addProposal_splitVariableDeclaration();
-    _addProposal_surroundWith();
-    // done
-    return assists;
-  }
-
-  FunctionBody getEnclosingFunctionBody() {
-    {
-      FunctionExpression function =
-          node.getAncestor((node) => node is FunctionExpression);
-      if (function != null) {
-        return function.body;
-      }
-    }
-    {
-      FunctionDeclaration function =
-          node.getAncestor((node) => node is FunctionDeclaration);
-      if (function != null) {
-        return function.functionExpression.body;
-      }
-    }
-    {
-      MethodDeclaration method =
-          node.getAncestor((node) => node is MethodDeclaration);
-      if (method != null) {
-        return method.body;
-      }
-    }
-    return null;
-  }
-
-  void _addAssist(AssistKind kind, List args, {String assistFile}) {
-    if (assistFile == null) {
-      assistFile = file;
-    }
-    FileEdit fileEdit = new FileEdit(file);
-    fileEdit.addAll(edits);
-    // prepare Change
-    String message = formatList(kind.message, args);
-    Change change = new Change(message);
-    change.addFileEdit(fileEdit);
-    linkedPositionGroups.values.forEach(
-        (group) => change.addLinkedEditGroup(group));
-    change.selection = exitPosition;
-    // add Assist
-    Assist assist = new Assist(kind, change);
-    assists.add(assist);
-    // clear
-    edits.clear();
-    linkedPositionGroups.clear();
-    exitPosition = null;
-  }
-
-  /**
-   * Adds a new [Edit] to [edits].
-   */
-  void _addInsertEdit(int offset, String text) {
-    Edit edit = new Edit(offset, 0, text);
-    edits.add(edit);
-  }
-
-  void _addProposal_addTypeAnnotation() {
-    // prepare VariableDeclarationList
-    VariableDeclarationList declarationList =
-        node.getAncestor((node) => node is VariableDeclarationList);
-    if (declarationList == null) {
-      _coverageMarker();
-      return;
-    }
-    // may be has type annotation already
-    if (declarationList.type != null) {
-      _coverageMarker();
-      return;
-    }
-    // prepare single VariableDeclaration
-    List<VariableDeclaration> variables = declarationList.variables;
-    if (variables.length != 1) {
-      _coverageMarker();
-      return;
-    }
-    VariableDeclaration variable = variables[0];
-    // we need an initializer to get the type from
-    Expression initializer = variable.initializer;
-    if (initializer == null) {
-      _coverageMarker();
-      return;
-    }
-    DartType type = initializer.bestType;
-    // prepare type source
-    String typeSource;
-    if (type is InterfaceType || type is FunctionType) {
-      typeSource = utils.getTypeSource(type);
-    } else {
-      _coverageMarker();
-      return;
-    }
-    // add edit
-    Token keyword = declarationList.keyword;
-    if (keyword is KeywordToken && keyword.keyword == Keyword.VAR) {
-      SourceRange range = rangeToken(keyword);
-      _addReplaceEdit(range, typeSource);
-    } else {
-      _addInsertEdit(variable.offset, '$typeSource ');
-    }
-    // add proposal
-    _addAssist(AssistKind.ADD_TYPE_ANNOTATION, []);
-  }
-
-  void _addProposal_assignToLocalVariable() {
-    // prepare enclosing ExpressionStatement
-    Statement statement = node.getAncestor((node) => node is Statement);
-    if (statement is! ExpressionStatement) {
-      _coverageMarker();
-      return;
-    }
-    ExpressionStatement expressionStatement = statement as ExpressionStatement;
-    // prepare expression
-    Expression expression = expressionStatement.expression;
-    int offset = expression.offset;
-    // ignore if already assignment
-    if (expression is AssignmentExpression) {
-      _coverageMarker();
-      return;
-    }
-    // ignore "throw"
-    if (expression is ThrowExpression) {
-      _coverageMarker();
-      return;
-    }
-    // prepare expression type
-    DartType type = expression.bestType;
-    if (type.isVoid) {
-      _coverageMarker();
-      return;
-    }
-    // prepare source
-    SourceBuilder builder = new SourceBuilder(file, offset);
-    builder.append("var ");
-    // prepare excluded names
-    Set<String> excluded = new Set<String>();
-    {
-      ScopedNameFinder scopedNameFinder = new ScopedNameFinder(offset);
-      expression.accept(scopedNameFinder);
-      excluded.addAll(scopedNameFinder.locals.keys.toSet());
-    }
-    // name(s)
-    {
-      List<String> suggestions =
-          getVariableNameSuggestionsForExpression(type, expression, excluded);
-      builder.startPosition("NAME");
-      for (int i = 0; i < suggestions.length; i++) {
-        String name = suggestions[i];
-        if (i == 0) {
-          builder.append(name);
-        }
-        builder.addSuggestion(LinkedEditSuggestionKind.VARIABLE, name);
-      }
-      builder.endPosition();
-    }
-    builder.append(" = ");
-    // add proposal
-    _insertBuilder(builder);
-    _addAssist(AssistKind.ASSIGN_TO_LOCAL_VARIABLE, []);
-  }
-
-  void _addProposal_convertToBlockFunctionBody() {
-    FunctionBody body = getEnclosingFunctionBody();
-    // prepare expression body
-    if (body is! ExpressionFunctionBody) {
-      _coverageMarker();
-      return;
-    }
-    Expression returnValue = (body as ExpressionFunctionBody).expression;
-    // prepare prefix
-    String prefix = utils.getNodePrefix(body.parent);
-    // add change
-    String indent = utils.getIndent(1);
-    String returnSource = 'return ' + _getNodeText(returnValue);
-    String newBodySource = "{$eol$prefix${indent}$returnSource;$eol$prefix}";
-    _addReplaceEdit(rangeNode(body), newBodySource);
-    // add proposal
-    _addAssist(AssistKind.CONVERT_INTO_BLOCK_BODY, []);
-  }
-
-  void _addProposal_convertToExpressionFunctionBody() {
-    // prepare current body
-    FunctionBody body = getEnclosingFunctionBody();
-    if (body is! BlockFunctionBody) {
-      _coverageMarker();
-      return;
-    }
-    // prepare return statement
-    List<Statement> statements = (body as BlockFunctionBody).block.statements;
-    if (statements.length != 1) {
-      _coverageMarker();
-      return;
-    }
-    if (statements[0] is! ReturnStatement) {
-      _coverageMarker();
-      return;
-    }
-    ReturnStatement returnStatement = statements[0] as ReturnStatement;
-    // prepare returned expression
-    Expression returnExpression = returnStatement.expression;
-    if (returnExpression == null) {
-      _coverageMarker();
-      return;
-    }
-    // add change
-    String newBodySource = "=> ${_getNodeText(returnExpression)}";
-    if (body.parent is! FunctionExpression ||
-        body.parent.parent is FunctionDeclaration) {
-      newBodySource += ";";
-    }
-    _addReplaceEdit(rangeNode(body), newBodySource);
-    // add proposal
-    _addAssist(AssistKind.CONVERT_INTO_EXPRESSION_BODY, []);
-  }
-
-  /**
-   * Converts "!isEmpty" -> "isNotEmpty" if possible.
-   */
-  void _addProposal_convertToIsNotEmpty() {
-    // prepare "expr.isEmpty"
-    AstNode isEmptyAccess = null;
-    SimpleIdentifier isEmptyIdentifier = null;
-    if (node is SimpleIdentifier) {
-      SimpleIdentifier identifier = node as SimpleIdentifier;
-      AstNode parent = identifier.parent;
-      // normal case (but rare)
-      if (parent is PropertyAccess) {
-        isEmptyIdentifier = parent.propertyName;
-        isEmptyAccess = parent;
-      }
-      // usual case
-      if (parent is PrefixedIdentifier) {
-        isEmptyIdentifier = parent.identifier;
-        isEmptyAccess = parent;
-      }
-    }
-    if (isEmptyIdentifier == null) {
-      _coverageMarker();
-      return;
-    }
-    // should be "isEmpty"
-    Element propertyElement = isEmptyIdentifier.bestElement;
-    if (propertyElement == null || "isEmpty" != propertyElement.name) {
-      _coverageMarker();
-      return;
-    }
-    // should have "isNotEmpty"
-    Element propertyTarget = propertyElement.enclosingElement;
-    if (propertyTarget == null ||
-        getChildren(propertyTarget, "isNotEmpty").isEmpty) {
-      _coverageMarker();
-      return;
-    }
-    // should be in PrefixExpression
-    if (isEmptyAccess.parent is! PrefixExpression) {
-      _coverageMarker();
-      return;
-    }
-    PrefixExpression prefixExpression =
-        isEmptyAccess.parent as PrefixExpression;
-    // should be !
-    if (prefixExpression.operator.type != TokenType.BANG) {
-      return;
-    }
-    // do replace
-    _addRemoveEdit(rangeStartStart(prefixExpression, prefixExpression.operand));
-    _addReplaceEdit(rangeNode(isEmptyIdentifier), "isNotEmpty");
-    // add proposal
-    _addAssist(AssistKind.CONVERT_INTO_IS_NOT_EMPTY, []);
-  }
-
-  void _addProposal_convertToIsNot_onIs() {
-    // may be child of "is"
-    AstNode node = this.node;
-    while (node != null && node is! IsExpression) {
-      node = node.parent;
-    }
-    // prepare "is"
-    if (node is! IsExpression) {
-      _coverageMarker();
-      return;
-    }
-    IsExpression isExpression = node as IsExpression;
-    if (isExpression.notOperator != null) {
-      _coverageMarker();
-      return;
-    }
-    // prepare enclosing ()
-    AstNode parent = isExpression.parent;
-    if (parent is! ParenthesizedExpression) {
-      _coverageMarker();
-      return;
-    }
-    ParenthesizedExpression parExpression = parent as ParenthesizedExpression;
-    // prepare enclosing !()
-    AstNode parent2 = parent.parent;
-    if (parent2 is! PrefixExpression) {
-      _coverageMarker();
-      return;
-    }
-    PrefixExpression prefExpression = parent2 as PrefixExpression;
-    if (prefExpression.operator.type != TokenType.BANG) {
-      _coverageMarker();
-      return;
-    }
-    // strip !()
-    if (getExpressionParentPrecedence(prefExpression) >=
-        TokenType.IS.precedence) {
-      _addRemoveEdit(rangeToken(prefExpression.operator));
-    } else {
-      _addRemoveEdit(
-          rangeStartEnd(prefExpression, parExpression.leftParenthesis));
-      _addRemoveEdit(
-          rangeStartEnd(parExpression.rightParenthesis, prefExpression));
-    }
-    _addInsertEdit(isExpression.isOperator.end, "!");
-    // add proposal
-    _addAssist(AssistKind.CONVERT_INTO_IS_NOT, []);
-  }
-
-  void _addProposal_convertToIsNot_onNot() {
-    // may be () in prefix expression
-    if (node is ParenthesizedExpression && node.parent is PrefixExpression) {
-      node = node.parent;
-    }
-    // prepare !()
-    if (node is! PrefixExpression) {
-      _coverageMarker();
-      return;
-    }
-    PrefixExpression prefExpression = node as PrefixExpression;
-    // should be ! operator
-    if (prefExpression.operator.type != TokenType.BANG) {
-      _coverageMarker();
-      return;
-    }
-    // prepare !()
-    Expression operand = prefExpression.operand;
-    if (operand is! ParenthesizedExpression) {
-      _coverageMarker();
-      return;
-    }
-    ParenthesizedExpression parExpression = operand as ParenthesizedExpression;
-    operand = parExpression.expression;
-    // prepare "is"
-    if (operand is! IsExpression) {
-      _coverageMarker();
-      return;
-    }
-    IsExpression isExpression = operand as IsExpression;
-    if (isExpression.notOperator != null) {
-      _coverageMarker();
-      return;
-    }
-    // strip !()
-    if (getExpressionParentPrecedence(prefExpression) >=
-        TokenType.IS.precedence) {
-      _addRemoveEdit(rangeToken(prefExpression.operator));
-    } else {
-      _addRemoveEdit(
-          rangeStartEnd(prefExpression, parExpression.leftParenthesis));
-      _addRemoveEdit(
-          rangeStartEnd(parExpression.rightParenthesis, prefExpression));
-    }
-    _addInsertEdit(isExpression.isOperator.end, "!");
-    // add proposal
-    _addAssist(AssistKind.CONVERT_INTO_IS_NOT, []);
-  }
-
-  void _addProposal_exchangeOperands() {
-    // check that user invokes quick assist on binary expression
-    if (node is! BinaryExpression) {
-      _coverageMarker();
-      return;
-    }
-    BinaryExpression binaryExpression = node as BinaryExpression;
-    // prepare operator position
-    if (!_isOperatorSelected(
-        binaryExpression,
-        selectionOffset,
-        selectionLength)) {
-      _coverageMarker();
-      return;
-    }
-    // add edits
-    {
-      Expression leftOperand = binaryExpression.leftOperand;
-      Expression rightOperand = binaryExpression.rightOperand;
-      // find "wide" enclosing binary expression with same operator
-      while (binaryExpression.parent is BinaryExpression) {
-        BinaryExpression newBinaryExpression =
-            binaryExpression.parent as BinaryExpression;
-        if (newBinaryExpression.operator.type !=
-            binaryExpression.operator.type) {
-          _coverageMarker();
-          break;
-        }
-        binaryExpression = newBinaryExpression;
-      }
-      // exchange parts of "wide" expression parts
-      SourceRange leftRange = rangeStartEnd(binaryExpression, leftOperand);
-      SourceRange rightRange = rangeStartEnd(rightOperand, binaryExpression);
-      _addReplaceEdit(leftRange, _getRangeText(rightRange));
-      _addReplaceEdit(rightRange, _getRangeText(leftRange));
-    }
-    // add proposal
-    _addAssist(AssistKind.EXCHANGE_OPERANDS, []);
-  }
-
-  void _addProposal_importAddShow() {
-    // prepare ImportDirective
-    ImportDirective importDirective =
-        node.getAncestor((node) => node is ImportDirective);
-    if (importDirective == null) {
-      _coverageMarker();
-      return;
-    }
-    // there should be no existing combinators
-    if (importDirective.combinators.isNotEmpty) {
-      _coverageMarker();
-      return;
-    }
-    // prepare whole import namespace
-    ImportElement importElement = importDirective.element;
-    Map<String, Element> namespace = getImportNamespace(importElement);
-    // prepare names of referenced elements (from this import)
-    SplayTreeSet<String> referencedNames = new SplayTreeSet<String>();
-    _SimpleIdentifierRecursiveAstVisitor visitor =
-        new _SimpleIdentifierRecursiveAstVisitor((SimpleIdentifier node) {
-      Element element = node.staticElement;
-      if (namespace[node.name] == element) {
-        referencedNames.add(element.displayName);
-      }
-    });
-    unit.accept(visitor);
-    // ignore if unused
-    if (referencedNames.isEmpty) {
-      _coverageMarker();
-      return;
-    }
-    // prepare change
-    String showCombinator = " show ${StringUtils.join(referencedNames, ", ")}";
-    _addInsertEdit(importDirective.end - 1, showCombinator);
-    // add proposal
-    _addAssist(AssistKind.IMPORT_ADD_SHOW, []);
-  }
-
-  void _addProposal_invertIf() {
-    if (node is! IfStatement) {
-      return;
-    }
-    IfStatement ifStatement = node as IfStatement;
-    Expression condition = ifStatement.condition;
-    // should have both "then" and "else"
-    Statement thenStatement = ifStatement.thenStatement;
-    Statement elseStatement = ifStatement.elseStatement;
-    if (thenStatement == null || elseStatement == null) {
-      return;
-    }
-    // prepare source
-    String invertedCondition = utils.invertCondition(condition);
-    String thenSource = _getNodeText(thenStatement);
-    String elseSource = _getNodeText(elseStatement);
-    // do replacements
-    _addReplaceEdit(rangeNode(condition), invertedCondition);
-    _addReplaceEdit(rangeNode(thenStatement), elseSource);
-    _addReplaceEdit(rangeNode(elseStatement), thenSource);
-    // add proposal
-    _addAssist(AssistKind.INVERT_IF_STATEMENT, []);
-  }
-
-  void _addProposal_joinIfStatementInner() {
-    // climb up condition to the (supposedly) "if" statement
-    AstNode node = this.node;
-    while (node is Expression) {
-      node = node.parent;
-    }
-    // prepare target "if" statement
-    if (node is! IfStatement) {
-      _coverageMarker();
-      return;
-    }
-    IfStatement targetIfStatement = node as IfStatement;
-    if (targetIfStatement.elseStatement != null) {
-      _coverageMarker();
-      return;
-    }
-    // prepare inner "if" statement
-    Statement targetThenStatement = targetIfStatement.thenStatement;
-    Statement innerStatement = getSingleStatement(targetThenStatement);
-    if (innerStatement is! IfStatement) {
-      _coverageMarker();
-      return;
-    }
-    IfStatement innerIfStatement = innerStatement as IfStatement;
-    if (innerIfStatement.elseStatement != null) {
-      _coverageMarker();
-      return;
-    }
-    // prepare environment
-    String prefix = utils.getNodePrefix(targetIfStatement);
-    // merge conditions
-    String condition;
-    {
-      Expression targetCondition = targetIfStatement.condition;
-      Expression innerCondition = innerIfStatement.condition;
-      String targetConditionSource = _getNodeText(targetCondition);
-      String innerConditionSource = _getNodeText(innerCondition);
-      if (_shouldWrapParenthesisBeforeAnd(targetCondition)) {
-        targetConditionSource = "(${targetConditionSource})";
-      }
-      if (_shouldWrapParenthesisBeforeAnd(innerCondition)) {
-        innerConditionSource = "(${innerConditionSource})";
-      }
-      condition = "${targetConditionSource} && ${innerConditionSource}";
-    }
-    // replace target "if" statement
-    {
-      Statement innerThenStatement = innerIfStatement.thenStatement;
-      List<Statement> innerThenStatements = getStatements(innerThenStatement);
-      SourceRange lineRanges =
-          utils.getLinesRangeStatements(innerThenStatements);
-      String oldSource = utils.getRangeText(lineRanges);
-      String newSource = utils.indentSourceLeftRight(oldSource, false);
-      _addReplaceEdit(
-          rangeNode(targetIfStatement),
-          "if ($condition) {${eol}${newSource}${prefix}}");
-    }
-    // done
-    _addAssist(AssistKind.JOIN_IF_WITH_INNER, []);
-  }
-
-  void _addProposal_joinIfStatementOuter() {
-    // climb up condition to the (supposedly) "if" statement
-    AstNode node = this.node;
-    while (node is Expression) {
-      node = node.parent;
-    }
-    // prepare target "if" statement
-    if (node is! IfStatement) {
-      _coverageMarker();
-      return;
-    }
-    IfStatement targetIfStatement = node as IfStatement;
-    if (targetIfStatement.elseStatement != null) {
-      _coverageMarker();
-      return;
-    }
-    // prepare outer "if" statement
-    AstNode parent = targetIfStatement.parent;
-    if (parent is Block) {
-      parent = parent.parent;
-    }
-    if (parent is! IfStatement) {
-      _coverageMarker();
-      return;
-    }
-    IfStatement outerIfStatement = parent as IfStatement;
-    if (outerIfStatement.elseStatement != null) {
-      _coverageMarker();
-      return;
-    }
-    // prepare environment
-    String prefix = utils.getNodePrefix(outerIfStatement);
-    // merge conditions
-    String condition;
-    {
-      Expression targetCondition = targetIfStatement.condition;
-      Expression outerCondition = outerIfStatement.condition;
-      String targetConditionSource = _getNodeText(targetCondition);
-      String outerConditionSource = _getNodeText(outerCondition);
-      if (_shouldWrapParenthesisBeforeAnd(targetCondition)) {
-        targetConditionSource = "(${targetConditionSource})";
-      }
-      if (_shouldWrapParenthesisBeforeAnd(outerCondition)) {
-        outerConditionSource = "(${outerConditionSource})";
-      }
-      condition = "${outerConditionSource} && ${targetConditionSource}";
-    }
-    // replace outer "if" statement
-    {
-      Statement targetThenStatement = targetIfStatement.thenStatement;
-      List<Statement> targetThenStatements = getStatements(targetThenStatement);
-      SourceRange lineRanges =
-          utils.getLinesRangeStatements(targetThenStatements);
-      String oldSource = utils.getRangeText(lineRanges);
-      String newSource = utils.indentSourceLeftRight(oldSource, false);
-      _addReplaceEdit(
-          rangeNode(outerIfStatement),
-          "if ($condition) {${eol}${newSource}${prefix}}");
-    }
-    // done
-    _addAssist(AssistKind.JOIN_IF_WITH_OUTER, []);
-  }
-
-  void _addProposal_joinVariableDeclaration_onAssignment() {
-    // check that node is LHS in assignment
-    if (node is SimpleIdentifier &&
-        node.parent is AssignmentExpression &&
-        (node.parent as AssignmentExpression).leftHandSide == node &&
-        node.parent.parent is ExpressionStatement) {
-    } else {
-      _coverageMarker();
-      return;
-    }
-    AssignmentExpression assignExpression = node.parent as AssignmentExpression;
-    // check that binary expression is assignment
-    if (assignExpression.operator.type != TokenType.EQ) {
-      _coverageMarker();
-      return;
-    }
-    // prepare "declaration" statement
-    Element element = (node as SimpleIdentifier).staticElement;
-    if (element == null) {
-      _coverageMarker();
-      return;
-    }
-    int declOffset = element.nameOffset;
-    AstNode declNode = new NodeLocator.con1(declOffset).searchWithin(unit);
-    if (declNode != null &&
-        declNode.parent is VariableDeclaration &&
-        (declNode.parent as VariableDeclaration).name == declNode &&
-        declNode.parent.parent is VariableDeclarationList &&
-        declNode.parent.parent.parent is VariableDeclarationStatement) {
-    } else {
-      _coverageMarker();
-      return;
-    }
-    VariableDeclaration decl = declNode.parent as VariableDeclaration;
-    VariableDeclarationStatement declStatement =
-        decl.parent.parent as VariableDeclarationStatement;
-    // may be has initializer
-    if (decl.initializer != null) {
-      _coverageMarker();
-      return;
-    }
-    // check that "declaration" statement declared only one variable
-    if (declStatement.variables.variables.length != 1) {
-      _coverageMarker();
-      return;
-    }
-    // check that the "declaration" and "assignment" statements are
-    // parts of the same Block
-    ExpressionStatement assignStatement =
-        node.parent.parent as ExpressionStatement;
-    if (assignStatement.parent is Block &&
-        assignStatement.parent == declStatement.parent) {
-    } else {
-      _coverageMarker();
-      return;
-    }
-    Block block = assignStatement.parent as Block;
-    // check that "declaration" and "assignment" statements are adjacent
-    List<Statement> statements = block.statements;
-    if (statements.indexOf(assignStatement) ==
-        statements.indexOf(declStatement) + 1) {
-    } else {
-      _coverageMarker();
-      return;
-    }
-    // add edits
-    {
-      int assignOffset = assignExpression.operator.offset;
-      _addReplaceEdit(rangeEndStart(declNode, assignOffset), " ");
-    }
-    // add proposal
-    _addAssist(AssistKind.JOIN_VARIABLE_DECLARATION, []);
-  }
-
-  void _addProposal_joinVariableDeclaration_onDeclaration() {
-    // prepare enclosing VariableDeclarationList
-    VariableDeclarationList declList =
-        node.getAncestor((node) => node is VariableDeclarationList);
-    if (declList != null && declList.variables.length == 1) {
-    } else {
-      _coverageMarker();
-      return;
-    }
-    VariableDeclaration decl = declList.variables[0];
-    // already initialized
-    if (decl.initializer != null) {
-      _coverageMarker();
-      return;
-    }
-    // prepare VariableDeclarationStatement in Block
-    if (declList.parent is VariableDeclarationStatement &&
-        declList.parent.parent is Block) {
-    } else {
-      _coverageMarker();
-      return;
-    }
-    VariableDeclarationStatement declStatement =
-        declList.parent as VariableDeclarationStatement;
-    Block block = declStatement.parent as Block;
-    List<Statement> statements = block.statements;
-    // prepare assignment
-    AssignmentExpression assignExpression;
-    {
-      // declaration should not be last Statement
-      int declIndex = statements.indexOf(declStatement);
-      if (declIndex < statements.length - 1) {
-      } else {
-        _coverageMarker();
-        return;
-      }
-      // next Statement should be assignment
-      Statement assignStatement = statements[declIndex + 1];
-      if (assignStatement is ExpressionStatement) {
-      } else {
-        _coverageMarker();
-        return;
-      }
-      ExpressionStatement expressionStatement =
-          assignStatement as ExpressionStatement;
-      // expression should be assignment
-      if (expressionStatement.expression is AssignmentExpression) {
-      } else {
-        _coverageMarker();
-        return;
-      }
-      assignExpression = expressionStatement.expression as AssignmentExpression;
-    }
-    // check that pure assignment
-    if (assignExpression.operator.type != TokenType.EQ) {
-      _coverageMarker();
-      return;
-    }
-    // add edits
-    {
-      int assignOffset = assignExpression.operator.offset;
-      _addReplaceEdit(rangeEndStart(decl.name, assignOffset), " ");
-    }
-    // add proposal
-    _addAssist(AssistKind.JOIN_VARIABLE_DECLARATION, []);
-  }
-
-  void _addProposal_removeTypeAnnotation() {
-    AstNode typeStart = null;
-    AstNode typeEnd = null;
-    // try top-level variable
-    {
-      TopLevelVariableDeclaration declaration =
-          node.getAncestor((node) => node is TopLevelVariableDeclaration);
-      if (declaration != null) {
-        TypeName typeNode = declaration.variables.type;
-        if (typeNode != null) {
-          VariableDeclaration field = declaration.variables.variables[0];
-          typeStart = declaration;
-          typeEnd = field;
-        }
-      }
-    }
-    // try class field
-    {
-      FieldDeclaration fieldDeclaration =
-          node.getAncestor((node) => node is FieldDeclaration);
-      if (fieldDeclaration != null) {
-        TypeName typeNode = fieldDeclaration.fields.type;
-        if (typeNode != null) {
-          VariableDeclaration field = fieldDeclaration.fields.variables[0];
-          typeStart = fieldDeclaration;
-          typeEnd = field;
-        }
-      }
-    }
-    // try local variable
-    {
-      VariableDeclarationStatement statement =
-          node.getAncestor((node) => node is VariableDeclarationStatement);
-      if (statement != null) {
-        TypeName typeNode = statement.variables.type;
-        if (typeNode != null) {
-          VariableDeclaration variable = statement.variables.variables[0];
-          typeStart = typeNode;
-          typeEnd = variable;
-        }
-      }
-    }
-    // add edit
-    if (typeStart != null && typeEnd != null) {
-      SourceRange typeRange = rangeStartStart(typeStart, typeEnd);
-      _addReplaceEdit(typeRange, "var ");
-    }
-    // add proposal
-    _addAssist(AssistKind.REMOVE_TYPE_ANNOTATION, []);
-  }
-
-  void _addProposal_replaceConditionalWithIfElse() {
-    ConditionalExpression conditional = null;
-    // may be on Statement with Conditional
-    Statement statement = node.getAncestor((node) => node is Statement);
-    if (statement == null) {
-      _coverageMarker();
-      return;
-    }
-    // variable declaration
-    bool inVariable = false;
-    if (statement is VariableDeclarationStatement) {
-      VariableDeclarationStatement variableStatement = statement;
-      for (VariableDeclaration variable in
-          variableStatement.variables.variables) {
-        if (variable.initializer is ConditionalExpression) {
-          conditional = variable.initializer as ConditionalExpression;
-          inVariable = true;
-          break;
-        }
-      }
-    }
-    // assignment
-    bool inAssignment = false;
-    if (statement is ExpressionStatement) {
-      ExpressionStatement exprStmt = statement;
-      if (exprStmt.expression is AssignmentExpression) {
-        AssignmentExpression assignment =
-            exprStmt.expression as AssignmentExpression;
-        if (assignment.operator.type == TokenType.EQ &&
-            assignment.rightHandSide is ConditionalExpression) {
-          conditional = assignment.rightHandSide as ConditionalExpression;
-          inAssignment = true;
-        }
-      }
-    }
-    // return
-    bool inReturn = false;
-    if (statement is ReturnStatement) {
-      ReturnStatement returnStatement = statement;
-      if (returnStatement.expression is ConditionalExpression) {
-        conditional = returnStatement.expression as ConditionalExpression;
-        inReturn = true;
-      }
-    }
-    // prepare environment
-    String indent = utils.getIndent(1);
-    String prefix = utils.getNodePrefix(statement);
-    // Type v = Conditional;
-    if (inVariable) {
-      VariableDeclaration variable = conditional.parent as VariableDeclaration;
-      _addRemoveEdit(rangeEndEnd(variable.name, conditional));
-      String conditionSrc = _getNodeText(conditional.condition);
-      String thenSrc = _getNodeText(conditional.thenExpression);
-      String elseSrc = _getNodeText(conditional.elseExpression);
-      String name = variable.name.name;
-      String src = eol;
-      src += prefix + 'if ($conditionSrc) {' + eol;
-      src += prefix + indent + '$name = $thenSrc;' + eol;
-      src += prefix + '} else {' + eol;
-      src += prefix + indent + '$name = $elseSrc;' + eol;
-      src += prefix + '}';
-      _addReplaceEdit(rangeEndLength(statement, 0), src);
-    }
-    // v = Conditional;
-    if (inAssignment) {
-      AssignmentExpression assignment =
-          conditional.parent as AssignmentExpression;
-      Expression leftSide = assignment.leftHandSide;
-      String conditionSrc = _getNodeText(conditional.condition);
-      String thenSrc = _getNodeText(conditional.thenExpression);
-      String elseSrc = _getNodeText(conditional.elseExpression);
-      String name = _getNodeText(leftSide);
-      String src = '';
-      src += 'if ($conditionSrc) {' + eol;
-      src += prefix + indent + '$name = $thenSrc;' + eol;
-      src += prefix + '} else {' + eol;
-      src += prefix + indent + '$name = $elseSrc;' + eol;
-      src += prefix + '}';
-      _addReplaceEdit(rangeNode(statement), src);
-    }
-    // return Conditional;
-    if (inReturn) {
-      String conditionSrc = _getNodeText(conditional.condition);
-      String thenSrc = _getNodeText(conditional.thenExpression);
-      String elseSrc = _getNodeText(conditional.elseExpression);
-      String src = '';
-      src += 'if ($conditionSrc) {' + eol;
-      src += prefix + indent + 'return $thenSrc;' + eol;
-      src += prefix + '} else {' + eol;
-      src += prefix + indent + 'return $elseSrc;' + eol;
-      src += prefix + '}';
-      _addReplaceEdit(rangeNode(statement), src);
-    }
-    // add proposal
-    _addAssist(AssistKind.REPLACE_CONDITIONAL_WITH_IF_ELSE, []);
-  }
-
-  void _addProposal_replaceIfElseWithConditional() {
-    // should be "if"
-    if (node is! IfStatement) {
-      _coverageMarker();
-      return;
-    }
-    IfStatement ifStatement = node as IfStatement;
-    // single then/else statements
-    Statement thenStatement = getSingleStatement(ifStatement.thenStatement);
-    Statement elseStatement = getSingleStatement(ifStatement.elseStatement);
-    if (thenStatement == null || elseStatement == null) {
-      _coverageMarker();
-      return;
-    }
-    // returns
-    if (thenStatement is ReturnStatement || elseStatement is ReturnStatement) {
-      ReturnStatement thenReturn = thenStatement as ReturnStatement;
-      ReturnStatement elseReturn = elseStatement as ReturnStatement;
-      String conditionSrc = _getNodeText(ifStatement.condition);
-      String theSrc = _getNodeText(thenReturn.expression);
-      String elseSrc = _getNodeText(elseReturn.expression);
-      _addReplaceEdit(
-          rangeNode(ifStatement),
-          'return $conditionSrc ? $theSrc : $elseSrc;');
-    }
-    // assignments -> v = Conditional;
-    if (thenStatement is ExpressionStatement &&
-        elseStatement is ExpressionStatement) {
-      Expression thenExpression = thenStatement.expression;
-      Expression elseExpression = elseStatement.expression;
-      if (thenExpression is AssignmentExpression &&
-          elseExpression is AssignmentExpression) {
-        AssignmentExpression thenAssignment = thenExpression;
-        AssignmentExpression elseAssignment = elseExpression;
-        String thenTarget = _getNodeText(thenAssignment.leftHandSide);
-        String elseTarget = _getNodeText(elseAssignment.leftHandSide);
-        if (thenAssignment.operator.type == TokenType.EQ &&
-            elseAssignment.operator.type == TokenType.EQ &&
-            StringUtils.equals(thenTarget, elseTarget)) {
-          String conditionSrc = _getNodeText(ifStatement.condition);
-          String theSrc = _getNodeText(thenAssignment.rightHandSide);
-          String elseSrc = _getNodeText(elseAssignment.rightHandSide);
-          _addReplaceEdit(
-              rangeNode(ifStatement),
-              '$thenTarget = $conditionSrc ? $theSrc : $elseSrc;');
-        }
-      }
-    }
-    // add proposal
-    _addAssist(AssistKind.REPLACE_IF_ELSE_WITH_CONDITIONAL, []);
-  }
-
-  void _addProposal_splitAndCondition() {
-    // check that user invokes quick assist on binary expression
-    if (node is! BinaryExpression) {
-      _coverageMarker();
-      return;
-    }
-    BinaryExpression binaryExpression = node as BinaryExpression;
-    // prepare operator position
-    if (!_isOperatorSelected(
-        binaryExpression,
-        selectionOffset,
-        selectionLength)) {
-      _coverageMarker();
-      return;
-    }
-    // should be &&
-    if (binaryExpression.operator.type != TokenType.AMPERSAND_AMPERSAND) {
-      _coverageMarker();
-      return;
-    }
-    // prepare "if"
-    Statement statement = node.getAncestor((node) => node is Statement);
-    if (statement is! IfStatement) {
-      _coverageMarker();
-      return;
-    }
-    IfStatement ifStatement = statement as IfStatement;
-    // check that binary expression is part of first level && condition of "if"
-    BinaryExpression condition = binaryExpression;
-    while (condition.parent is BinaryExpression &&
-        (condition.parent as BinaryExpression).operator.type ==
-            TokenType.AMPERSAND_AMPERSAND) {
-      condition = condition.parent as BinaryExpression;
-    }
-    if (ifStatement.condition != condition) {
-      _coverageMarker();
-      return;
-    }
-    // prepare environment
-    String prefix = utils.getNodePrefix(ifStatement);
-    String indent = utils.getIndent(1);
-    // prepare "rightCondition"
-    String rightConditionSource;
-    {
-      SourceRange rightConditionRange =
-          rangeStartEnd(binaryExpression.rightOperand, condition);
-      rightConditionSource = _getRangeText(rightConditionRange);
-    }
-    // remove "&& rightCondition"
-    _addRemoveEdit(rangeEndEnd(binaryExpression.leftOperand, condition));
-    // update "then" statement
-    Statement thenStatement = ifStatement.thenStatement;
-    Statement elseStatement = ifStatement.elseStatement;
-    if (thenStatement is Block) {
-      Block thenBlock = thenStatement;
-      SourceRange thenBlockRange = rangeNode(thenBlock);
-      // insert inner "if" with right part of "condition"
-      {
-        String source =
-            "${eol}${prefix}${indent}if (${rightConditionSource}) {";
-        int thenBlockInsideOffset = thenBlockRange.offset + 1;
-        _addInsertEdit(thenBlockInsideOffset, source);
-      }
-      // insert closing "}" for inner "if"
-      {
-        int thenBlockEnd = thenBlockRange.end;
-        String source = "${indent}}";
-        // may be move "else" statements
-        if (elseStatement != null) {
-          List<Statement> elseStatements = getStatements(elseStatement);
-          SourceRange elseLinesRange =
-              utils.getLinesRangeStatements(elseStatements);
-          String elseIndentOld = "${prefix}${indent}";
-          String elseIndentNew = "${elseIndentOld}${indent}";
-          String newElseSource =
-              utils.replaceSourceRangeIndent(elseLinesRange, elseIndentOld, elseIndentNew);
-          // append "else" block
-          source += " else {${eol}";
-          source += newElseSource;
-          source += "${prefix}${indent}}";
-          // remove old "else" range
-          _addRemoveEdit(rangeStartEnd(thenBlockEnd, elseStatement));
-        }
-        // insert before outer "then" block "}"
-        source += "${eol}${prefix}";
-        _addInsertEdit(thenBlockEnd - 1, source);
-      }
-    } else {
-      // insert inner "if" with right part of "condition"
-      {
-        String source = "${eol}${prefix}${indent}if (${rightConditionSource})";
-        _addInsertEdit(ifStatement.rightParenthesis.offset + 1, source);
-      }
-      // indent "else" statements to correspond inner "if"
-      if (elseStatement != null) {
-        SourceRange elseRange =
-            rangeStartEnd(ifStatement.elseKeyword.offset, elseStatement);
-        SourceRange elseLinesRange = utils.getLinesRange(elseRange);
-        String elseIndentOld = prefix;
-        String elseIndentNew = "${elseIndentOld}${indent}";
-        edits.add(
-            utils.createIndentEdit(elseLinesRange, elseIndentOld, elseIndentNew));
-      }
-    }
-    // indent "then" statements to correspond inner "if"
-    {
-      List<Statement> thenStatements = getStatements(thenStatement);
-      SourceRange linesRange = utils.getLinesRangeStatements(thenStatements);
-      String thenIndentOld = "${prefix}${indent}";
-      String thenIndentNew = "${thenIndentOld}${indent}";
-      edits.add(
-          utils.createIndentEdit(linesRange, thenIndentOld, thenIndentNew));
-    }
-    // add proposal
-    _addAssist(AssistKind.SPLIT_AND_CONDITION, []);
-  }
-
-  void _addProposal_splitVariableDeclaration() {
-    // prepare DartVariableStatement, should be part of Block
-    VariableDeclarationStatement statement =
-        node.getAncestor((node) => node is VariableDeclarationStatement);
-    if (statement != null && statement.parent is Block) {
-    } else {
-      _coverageMarker();
-      return;
-    }
-    // check that statement declares single variable
-    List<VariableDeclaration> variables = statement.variables.variables;
-    if (variables.length != 1) {
-      _coverageMarker();
-      return;
-    }
-    VariableDeclaration variable = variables[0];
-    // prepare initializer
-    Expression initializer = variable.initializer;
-    if (initializer == null) {
-      _coverageMarker();
-      return;
-    }
-    // remove initializer value
-    _addRemoveEdit(rangeEndStart(variable.name, statement.semicolon));
-    // add assignment statement
-    String indent = utils.getNodePrefix(statement);
-    String name = variable.name.name;
-    String initSrc = _getNodeText(initializer);
-    SourceRange assignRange = rangeEndLength(statement, 0);
-    _addReplaceEdit(assignRange, eol + indent + name + ' = ' + initSrc + ';');
-    // add proposal
-    _addAssist(AssistKind.SPLIT_VARIABLE_DECLARATION, []);
-  }
-
-  void _addProposal_surroundWith() {
-    // prepare selected statements
-    List<Statement> selectedStatements;
-    {
-      SourceRange selection =
-          rangeStartLength(selectionOffset, selectionLength);
-      StatementAnalyzer selectionAnalyzer =
-          new StatementAnalyzer(unit, selection);
-      unit.accept(selectionAnalyzer);
-      List<AstNode> selectedNodes = selectionAnalyzer.selectedNodes;
-      // convert nodes to statements
-      selectedStatements = [];
-      for (AstNode selectedNode in selectedNodes) {
-        if (selectedNode is Statement) {
-          selectedStatements.add(selectedNode);
-        }
-      }
-      // we want only statements
-      if (selectedStatements.isEmpty ||
-          selectedStatements.length != selectedNodes.length) {
-        return;
-      }
-    }
-    // prepare statement information
-    Statement firstStatement = selectedStatements[0];
-    Statement lastStatement = selectedStatements[selectedStatements.length - 1];
-    SourceRange statementsRange =
-        utils.getLinesRangeStatements(selectedStatements);
-    // prepare environment
-    String indentOld = utils.getNodePrefix(firstStatement);
-    String indentNew = "${indentOld}${utils.getIndent(1)}";
-    // "block"
-    {
-      _addInsertEdit(statementsRange.offset, "${indentOld}{${eol}");
-      {
-        Edit edit =
-            utils.createIndentEdit(statementsRange, indentOld, indentNew);
-        edits.add(edit);
-      }
-      _addInsertEdit(statementsRange.end, "${indentOld}}${eol}");
-      exitPosition = _newPosition(lastStatement.end);
-      // add proposal
-      _addAssist(AssistKind.SURROUND_WITH_BLOCK, []);
-    }
-    // "if"
-    {
-      {
-        int offset = statementsRange.offset;
-        SourceBuilder sb = new SourceBuilder(file, offset);
-        sb.append(indentOld);
-        sb.append("if (");
-        {
-          sb.startPosition("CONDITION");
-          sb.append("condition");
-          sb.endPosition();
-        }
-        sb.append(") {");
-        sb.append(eol);
-        _insertBuilder(sb);
-      }
-      {
-        Edit edit =
-            utils.createIndentEdit(statementsRange, indentOld, indentNew);
-        edits.add(edit);
-      }
-      _addInsertEdit(statementsRange.end, "${indentOld}}${eol}");
-      exitPosition = _newPosition(lastStatement.end);
-      // add proposal
-      _addAssist(AssistKind.SURROUND_WITH_IF, []);
-    }
-    // "while"
-    {
-      {
-        int offset = statementsRange.offset;
-        SourceBuilder sb = new SourceBuilder(file, offset);
-        sb.append(indentOld);
-        sb.append("while (");
-        {
-          sb.startPosition("CONDITION");
-          sb.append("condition");
-          sb.endPosition();
-        }
-        sb.append(") {");
-        sb.append(eol);
-        _insertBuilder(sb);
-      }
-      {
-        Edit edit =
-            utils.createIndentEdit(statementsRange, indentOld, indentNew);
-        edits.add(edit);
-      }
-      _addInsertEdit(statementsRange.end, "${indentOld}}${eol}");
-      exitPosition = _newPosition(lastStatement.end);
-      // add proposal
-      _addAssist(AssistKind.SURROUND_WITH_WHILE, []);
-    }
-    // "for-in"
-    {
-      {
-        int offset = statementsRange.offset;
-        SourceBuilder sb = new SourceBuilder(file, offset);
-        sb.append(indentOld);
-        sb.append("for (var ");
-        {
-          sb.startPosition("NAME");
-          sb.append("item");
-          sb.endPosition();
-        }
-        sb.append(" in ");
-        {
-          sb.startPosition("ITERABLE");
-          sb.append("iterable");
-          sb.endPosition();
-        }
-        sb.append(") {");
-        sb.append(eol);
-        _insertBuilder(sb);
-      }
-      {
-        Edit edit =
-            utils.createIndentEdit(statementsRange, indentOld, indentNew);
-        edits.add(edit);
-      }
-      _addInsertEdit(statementsRange.end, "${indentOld}}${eol}");
-      exitPosition = _newPosition(lastStatement.end);
-      // add proposal
-      _addAssist(AssistKind.SURROUND_WITH_FOR_IN, []);
-    }
-    // "for"
-    {
-      {
-        int offset = statementsRange.offset;
-        SourceBuilder sb = new SourceBuilder(file, offset);
-        sb.append(indentOld);
-        sb.append("for (var ");
-        {
-          sb.startPosition("VAR");
-          sb.append("v");
-          sb.endPosition();
-        }
-        sb.append(" = ");
-        {
-          sb.startPosition("INIT");
-          sb.append("init");
-          sb.endPosition();
-        }
-        sb.append("; ");
-        {
-          sb.startPosition("CONDITION");
-          sb.append("condition");
-          sb.endPosition();
-        }
-        sb.append("; ");
-        {
-          sb.startPosition("INCREMENT");
-          sb.append("increment");
-          sb.endPosition();
-        }
-        sb.append(") {");
-        sb.append(eol);
-        _insertBuilder(sb);
-      }
-      {
-        Edit edit =
-            utils.createIndentEdit(statementsRange, indentOld, indentNew);
-        edits.add(edit);
-      }
-      _addInsertEdit(statementsRange.end, "${indentOld}}${eol}");
-      exitPosition = _newPosition(lastStatement.end);
-      // add proposal
-      _addAssist(AssistKind.SURROUND_WITH_FOR, []);
-    }
-    // "do-while"
-    {
-      _addInsertEdit(statementsRange.offset, "${indentOld}do {${eol}");
-      {
-        Edit edit =
-            utils.createIndentEdit(statementsRange, indentOld, indentNew);
-        edits.add(edit);
-      }
-      {
-        int offset = statementsRange.end;
-        SourceBuilder sb = new SourceBuilder(file, offset);
-        sb.append(indentOld);
-        sb.append("} while (");
-        {
-          sb.startPosition("CONDITION");
-          sb.append("condition");
-          sb.endPosition();
-        }
-        sb.append(");");
-        sb.append(eol);
-        _insertBuilder(sb);
-      }
-      exitPosition = _newPosition(lastStatement.end);
-      // add proposal
-      _addAssist(AssistKind.SURROUND_WITH_DO_WHILE, []);
-    }
-    // "try-catch"
-    {
-      _addInsertEdit(statementsRange.offset, "${indentOld}try {${eol}");
-      {
-        Edit edit =
-            utils.createIndentEdit(statementsRange, indentOld, indentNew);
-        edits.add(edit);
-      }
-      {
-        int offset = statementsRange.end;
-        SourceBuilder sb = new SourceBuilder(file, offset);
-        sb.append(indentOld);
-        sb.append("} on ");
-        {
-          sb.startPosition("EXCEPTION_TYPE");
-          sb.append("Exception");
-          sb.endPosition();
-        }
-        sb.append(" catch (");
-        {
-          sb.startPosition("EXCEPTION_VAR");
-          sb.append("e");
-          sb.endPosition();
-        }
-        sb.append(") {");
-        sb.append(eol);
-        //
-        sb.append(indentNew);
-        {
-          sb.startPosition("CATCH");
-          sb.append("// TODO");
-          sb.endPosition();
-          sb.setExitOffset();
-        }
-        sb.append(eol);
-        //
-        sb.append(indentOld);
-        sb.append("}");
-        sb.append(eol);
-        //
-        _insertBuilder(sb);
-        exitPosition = _newPosition(sb.exitOffset);
-      }
-      // add proposal
-      _addAssist(AssistKind.SURROUND_WITH_TRY_CATCH, []);
-    }
-    // "try-finally"
-    {
-      _addInsertEdit(statementsRange.offset, "${indentOld}try {${eol}");
-      {
-        Edit edit =
-            utils.createIndentEdit(statementsRange, indentOld, indentNew);
-        edits.add(edit);
-      }
-      {
-        int offset = statementsRange.end;
-        SourceBuilder sb = new SourceBuilder(file, offset);
-        //
-        sb.append(indentOld);
-        sb.append("} finally {");
-        sb.append(eol);
-        //
-        sb.append(indentNew);
-        {
-          sb.startPosition("FINALLY");
-          sb.append("// TODO");
-          sb.endPosition();
-        }
-        sb.setExitOffset();
-        sb.append(eol);
-        //
-        sb.append(indentOld);
-        sb.append("}");
-        sb.append(eol);
-        //
-        _insertBuilder(sb);
-        exitPosition = _newPosition(sb.exitOffset);
-      }
-      // add proposal
-      _addAssist(AssistKind.SURROUND_WITH_TRY_FINALLY, []);
-    }
-  }
-
-  /**
-   * Adds a new [Edit] to [edits].
-   */
-  void _addRemoveEdit(SourceRange range) {
-    _addReplaceEdit(range, '');
-  }
-
-  /**
-   * Adds a new [Edit] to [edits].
-   */
-  void _addReplaceEdit(SourceRange range, String text) {
-    Edit edit = new Edit(range.offset, range.length, text);
-    edits.add(edit);
-  }
-
-  /**
-   * Returns an existing or just added [LinkedEditGroup] with [groupId].
-   */
-  LinkedEditGroup _getLinkedPosition(String groupId) {
-    LinkedEditGroup group = linkedPositionGroups[groupId];
-    if (group == null) {
-      group = new LinkedEditGroup(groupId);
-      linkedPositionGroups[groupId] = group;
-    }
-    return group;
-  }
-
-  /**
-   * Returns the text of the given node in the unit.
-   */
-  String _getNodeText(AstNode node) {
-    return utils.getNodeText(node);
-  }
-
-  /**
-   * Returns the text of the given range in the unit.
-   */
-  String _getRangeText(SourceRange range) {
-    return utils.getRangeText(range);
-  }
-
-  /**
-   * Inserts the given [SourceBuilder] at its offset.
-   */
-  void _insertBuilder(SourceBuilder builder) {
-    String text = builder.toString();
-    _addInsertEdit(builder.offset, text);
-    // add linked positions
-    builder.linkedPositionGroups.forEach((LinkedEditGroup group) {
-      LinkedEditGroup fixGroup = _getLinkedPosition(group.id);
-      group.positions.forEach((Position position) {
-        fixGroup.addPosition(position, group.length);
-      });
-      group.suggestions.forEach((LinkedEditSuggestion suggestion) {
-        fixGroup.addSuggestion(suggestion);
-      });
-    });
-  }
-
-  Position _newPosition(int offset) {
-    return new Position(file, offset);
-  }
-
-  /**
-   * This method does nothing, but we invoke it in places where Dart VM
-   * coverage agent fails to provide coverage information - such as almost
-   * all "return" statements.
-   *
-   * https://code.google.com/p/dart/issues/detail?id=19912
-   */
-  static void _coverageMarker() {
-  }
-
-  /**
-   * Returns `true` if the selection covers an operator of the given
-   * [BinaryExpression].
-   */
-  static bool _isOperatorSelected(BinaryExpression binaryExpression, int offset,
-      int length) {
-    AstNode left = binaryExpression.leftOperand;
-    AstNode right = binaryExpression.rightOperand;
-    // between the nodes
-    if (offset >= left.endToken.end && offset + length <= right.offset) {
-      _coverageMarker();
-      return true;
-    }
-    // or exactly select the node (but not with infix expressions)
-    if (offset == left.offset && offset + length == right.endToken.end) {
-      if (left is BinaryExpression || right is BinaryExpression) {
-        _coverageMarker();
-        return false;
-      }
-      _coverageMarker();
-      return true;
-    }
-    // invalid selection (part of node, etc)
-    _coverageMarker();
-    return false;
-  }
-
-  /**
-   * Checks if the given [Expression] should be wrapped with parenthesis when we
-   * want to use it as operand of a logical `and` expression.
-   */
-  static bool _shouldWrapParenthesisBeforeAnd(Expression expr) {
-    if (expr is BinaryExpression) {
-      BinaryExpression binary = expr;
-      int precedence = binary.operator.type.precedence;
-      return precedence < TokenClass.LOGICAL_AND_OPERATOR.precedence;
-    }
-    return false;
-  }
-}
-
-
-class _SimpleIdentifierRecursiveAstVisitor extends RecursiveAstVisitor {
-  final _SimpleIdentifierVisitor visitor;
-
-  _SimpleIdentifierRecursiveAstVisitor(this.visitor);
-
-  @override
-  visitSimpleIdentifier(SimpleIdentifier node) {
-    visitor(node);
-  }
-}