anchor.diff:            }
           }
         } else if (offset == start && offset == end) {
  -        String data = request.sourceContents;
  +        var data = request.sourceContents;
           if (end == data.length) {
  -          String ch = data[end - 1];
  +          var ch = data[end - 1];
             if (ch == '"' || ch == "'") {
               // Insertion point at end of file
               // and missing closing quote on empty string
  
positive.code:             // Quoted empty string
              visitSimpleStringLiteral(uri);
            } else {
              String data = request.sourceContents;
              if (end == data.length) {
                String ch = data[end - 1];
                if (ch != '"' && ch != "'") {
                  // Insertion point at end of file
                  // and missing closing quote on non-empty string
  
negative.code:   }
  
    void visitNamespaceDirective(NamespaceDirective node) {
      var uri = node.uri;
      if (uri is SimpleStringLiteral) {
        var offset = request.offset;
        var start = uri.offset;
        var end = uri.end;
        if (offset > start) {
          if (offset < end) {
            // Quoted non-empty string
  