Issue 27903. Use shared logic for computing new method location.

pkg/analysis_server/lib/src/services/correction/fix_internal.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 analysis_server.src.services.correction.fix_internal;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:core';
 
@@ skipping 2018 matching lines @@
       }
     }
   }
 
   void _addFix_undefinedMethod_create() {
     if (node is SimpleIdentifier && node.parent is MethodInvocation) {
       String name = (node as SimpleIdentifier).name;
       MethodInvocation invocation = node.parent as MethodInvocation;
       // prepare environment
       Element targetElement;
-      String prefix;
-      int insertOffset;
-      String sourcePrefix;
-      String sourceSuffix;
       bool staticModifier = false;
+
+      ClassDeclaration targetClassNode;
       Expression target = invocation.realTarget;
       if (target == null) {
         targetElement = unitElement;
         ClassMember enclosingMember =
             node.getAncestor((node) => node is ClassMember);
-        ClassDeclaration enclosingClass = enclosingMember.parent;
-        utils.targetClassElement = enclosingClass.element;
+        targetClassNode = enclosingMember.parent;
+        utils.targetClassElement = targetClassNode.element;
         staticModifier = _inStaticContext();
-        prefix = utils.getNodePrefix(enclosingMember);
-        insertOffset = enclosingMember.end;
-        sourcePrefix = '$eol$eol';
-        sourceSuffix = '';
       } else {
         // prepare target interface type
         DartType targetType = target.bestType;
         if (targetType is! InterfaceType) {
           return;
         }
         ClassElement targetClassElement = targetType.element as ClassElement;
         targetElement = targetClassElement;
         // prepare target ClassDeclaration
         AstNode targetTypeNode = getParsedClassElementNode(targetClassElement);
         if (targetTypeNode is! ClassDeclaration) {
           return;
         }
-        ClassDeclaration targetClassNode = targetTypeNode;
+        targetClassNode = targetTypeNode;
         // maybe static
         if (target is Identifier) {
           staticModifier = target.bestElement.kind == ElementKind.CLASS;
         }
-        // prepare insert offset
-        prefix = '  ';
-        insertOffset = targetClassNode.end - 1;
-        if (targetClassNode.members.isEmpty) {
-          sourcePrefix = '';
-        } else {
-          sourcePrefix = eol;
-        }
-        sourceSuffix = eol;
         // use different utils
         CompilationUnitElement targetUnitElement =
             getCompilationUnitElement(targetClassElement);
         CompilationUnit targetUnit = getParsedUnit(targetUnitElement);
         utils = new CorrectionUtils(targetUnit);
       }
+      ClassMemberLocation targetLocation =
+          utils.prepareNewMethodLocation(targetClassNode);
       String targetFile = targetElement.source.fullName;
       // build method source
-      SourceBuilder sb = new SourceBuilder(targetFile, insertOffset);
+      SourceBuilder sb = new SourceBuilder(targetFile, targetLocation.offset);
       {
-        sb.append(sourcePrefix);
-        sb.append(prefix);
+        sb.append(targetLocation.prefix);
         // maybe "static"
         if (staticModifier) {
           sb.append('static ');
         }
         // append return type
         {
           DartType type = _inferUndefinedExpressionType(invocation);
           _appendType(sb, type, groupId: 'RETURN_TYPE');
         }
         // append name
         {
           sb.startPosition('NAME');
           sb.append(name);
           sb.endPosition();
         }
         _addFix_undefinedMethod_create_parameters(sb, invocation.argumentList);
-        sb.append(') {$eol$prefix}');
-        sb.append(sourceSuffix);
+        sb.append(') {}');
+        sb.append(targetLocation.suffix);
       }
       // insert source
       _insertBuilder(sb, targetElement);
       // add linked positions
       if (targetFile == file) {
         _addLinkedPosition('NAME', sb, rf.rangeNode(node));
       }
       // add proposal
       _addFix(DartFixKind.CREATE_METHOD, [name]);
     }
@@ skipping 830 matching lines @@
       }
     }
   }
 
   void _updateList(Iterable<Element> elements) {
     for (Element element in elements) {
       _update(element);
     }
   }
 }