(PUP-11841) Create mutable strings

In preparation for moving to frozen/immutable strings, explicitly create mutable
strings in cases where we create a string buffer and append to it. There are
multiple ways of creating a mutual string:

    ''.dup
    -''
    String.new

Although the latter is more verbose, I think it's better to be explicit.

Author: joshcooper

lib/puppet/application/doc.rb

@@ -151,7 +151,7 @@ def rdoc
   end
 
   def other
-    text = ""
+    text = String.new
     with_contents = options[:references].length <= 1
     exit_code = 0
     require_relative '../../puppet/util/reference'

lib/puppet/face/config.rb

@@ -81,7 +81,7 @@
     end
 
     when_rendering :console do |to_be_rendered|
-      output = ''
+      output = String.new
       if to_be_rendered.keys.length > 1
         to_be_rendered.keys.sort.each do |setting|
           output << "#{setting} = #{to_be_rendered[setting]}\n"

lib/puppet/face/epp.rb

@@ -366,7 +366,7 @@
   end
 
   def dump_parse(source, filename, options, show_filename = true)
-    output = ""
+    output = String.new
     evaluating_parser = Puppet::Pops::Parser::EvaluatingParser::EvaluatingEppParser.new
     begin
       if options[:validate]
@@ -450,7 +450,7 @@ def render_inline(epp_source, compiler, options)
 
   def render_file(epp_template_name, compiler, options, show_filename, file_nbr)
     template_args = get_values(compiler, options)
-    output = ""
+    output = String.new
     begin
       if show_filename && options[:header]
         output << "\n" unless file_nbr == 1

lib/puppet/face/module/list.rb

@@ -73,7 +73,7 @@
       environment     = result[:environment]
       modules_by_path = result[:modules_by_path]
 
-      output = ''
+      output = String.new
 
       warn_unmet_dependencies(environment)
 
@@ -247,7 +247,7 @@ def list_build_tree(list, ancestors=[], parent=nil, params={})
   # Returns a Hash
   #
   def list_build_node(mod, parent, params)
-    str = ''
+    str = String.new
     str << (mod.forge_name ? mod.forge_name.tr('/', '-') : mod.name)
     str << ' (' + colorize(:cyan, mod.version ? "v#{mod.version}" : '???') + ')'
 

lib/puppet/face/parser.rb

@@ -173,7 +173,7 @@
   end
 
   def dump_parse(source, filename, options, show_filename = true)
-    output = ""
+    output = String.new
     evaluating_parser = Puppet::Pops::Parser::EvaluatingParser.new
     begin
       if options[:validate]

lib/puppet/ffi/windows/api_types.rb

@@ -20,7 +20,7 @@ def attach_function_private(*args)
 
     class ::FFI::Pointer
       NULL_HANDLE = 0
-      WCHAR_NULL = "\0\0".force_encoding('UTF-16LE').freeze
+      WCHAR_NULL = String.new("\0\0").force_encoding('UTF-16LE').freeze
 
       def self.from_string_to_wide_string(str, &block)
         str = Puppet::Util::Windows::String.wide_string(str)

lib/puppet/file_system/posix.rb

@@ -12,8 +12,8 @@ def binread(path)
   def compare_stream(path, stream)
     open(path, 0, 'rb') do |this|
       bsize = stream_blksize(this, stream)
-      sa = "".force_encoding('ASCII-8BIT')
-      sb = "".force_encoding('ASCII-8BIT')
+      sa = String.new.force_encoding('ASCII-8BIT')
+      sb = String.new.force_encoding('ASCII-8BIT')
       loop do
         this.read(bsize, sa)
         stream.read(bsize, sb)

lib/puppet/indirector/file_bucket_file/file.rb

@@ -57,7 +57,7 @@ def list(request)
       end
       # Setting hash's default value to [], needed by the following loop
       bucket = Hash.new {[]}
-      msg = ""
+      msg = String.new
       # Get all files with mtime between 'from' and 'to'
       Pathname.new(request.options[:bucket_path]).find { |item|
         if item.file? and item.basename.to_s == "paths"

lib/puppet/indirector/indirection.rb

@@ -80,7 +80,7 @@ def expiration
 
   # Generate the full doc string.
   def doc
-    text = ""
+    text = String.new
 
     text << scrub(@doc) << "\n\n" if @doc
 

lib/puppet/module_tool.rb

@@ -69,7 +69,7 @@ def self.is_module_root?(path)
     # Builds a formatted tree from a list of node hashes containing +:text+
     # and +:dependencies+ keys.
     def self.format_tree(nodes, level = 0)
-      str = ''
+      str = String.new
       nodes.each_with_index do |node, i|
         last_node = nodes.length - 1 == i
         deps = node[:dependencies] || []

lib/puppet/network/formats.rb

@@ -155,7 +155,7 @@ def render(datum)
 
     # Simple hash to table
     if datum.is_a?(Hash) && datum.keys.all? { |x| x.is_a?(String) || x.is_a?(Numeric) }
-      output = ''
+      output = String.new
       column_a = datum.empty? ? 2 : datum.map{ |k,v| k.to_s.length }.max + 2
       datum.sort_by { |k,v| k.to_s } .each do |key, value|
         output << key.to_s.ljust(column_a)
@@ -168,7 +168,7 @@ def render(datum)
 
     # Print one item per line for arrays
     if datum.is_a? Array
-      output = ''
+      output = String.new
       datum.each do |item|
         output << item.to_s
         output << "\n"
@@ -226,7 +226,7 @@ def flatten_array(array)
   end
 
   def construct_output(data)
-    output = ''
+    output = String.new
     data.each do |key, value|
       output << "#{key}=#{value}"
       output << "\n"

lib/puppet/network/http/memory_response.rb

@@ -2,7 +2,7 @@ class Puppet::Network::HTTP::MemoryResponse
   attr_reader :code, :type, :body
 
   def initialize
-    @body = ""
+    @body = String.new
   end
 
   def respond_with(code, type, body)

lib/puppet/parameter/value_collection.rb

@@ -30,7 +30,7 @@ def aliasvalue(name, other)
   #
   def doc
     unless defined?(@doc)
-      @doc = ""
+      @doc = String.new
       unless values.empty?
         @doc << "Valid values are "
         @doc << @strings.collect do |value|

lib/puppet/parser/functions.rb

@@ -257,7 +257,7 @@ def self.function(name, environment = Puppet.lookup(:current_environment))
   def self.functiondocs(environment = Puppet.lookup(:current_environment))
     autoloader.delegatee.loadall(environment)
 
-    ret = ""
+    ret = String.new
 
     merged_functions(environment).sort { |a,b| a[0].to_s <=> b[0].to_s }.each do |name, hash|
       ret << "#{name}\n#{"-" * name.to_s.length}\n"

lib/puppet/pops/loader/loader_paths.rb

@@ -87,7 +87,7 @@ def effective_path(typed_name, start_index_in_name)
 
     def typed_name(type, name_authority, relative_path, module_name)
       # Module name is assumed to be included in the path and therefore not added here
-      n = ''
+      n = String.new
       unless extension.empty?
         # Remove extension
         relative_path = relative_path[0..-(extension.length+1)]
@@ -152,7 +152,7 @@ def effective_path(typed_name, start_index_in_name)
     end
 
     def typed_name(type, name_authority, relative_path, module_name)
-      n = ''
+      n = String.new
       n << module_name unless module_name.nil?
       unless extension.empty?
         # Remove extension
@@ -248,7 +248,7 @@ def relative_path
     end
 
     def typed_name(type, name_authority, relative_path, module_name)
-      n = ''
+      n = String.new
       n << module_name unless module_name.nil?
 
       # Remove the file extension, defined as everything after the *last* dot.
@@ -350,7 +350,7 @@ def typed_name(type, name_authority, relative_path, module_name)
       if @init_filenames.include?(relative_path) && !(module_name.nil? || module_name.empty?)
         TypedName.new(type, module_name, name_authority)
       else
-        n = ''
+        n = String.new
         n << module_name unless module_name.nil?
         ext = @extensions.find { |extension| relative_path.end_with?(extension) }
         relative_path = relative_path[0..-(ext.length+1)]

lib/puppet/pops/lookup/explainer.rb

@@ -19,7 +19,7 @@ def to_hash
     end
 
     def explain
-      io = ''
+      io = String.new
       dump_on(io, '', '')
       io
     end
@@ -585,7 +585,7 @@ def dump_on(io, indent, first_indent)
     end
 
     def emit_debug_info(preamble)
-      io = ''
+      io = String.new
       io << preamble << "\n"
       dump_on(io, '  ', '  ')
       Puppet.debug(io.chomp!)

lib/puppet/pops/lookup/hiera_config.rb

@@ -227,7 +227,7 @@ def find_line_matching(regexp, start_line = 1)
       line_number += 1
       next if line_number < start_line
       quote = nil
-      stripped = ''
+      stripped = String.new
       line.each_codepoint do |cp|
         if cp == 0x22 || cp == 0x27 # double or single quote
           if quote == cp

lib/puppet/pops/model/factory.rb

@@ -1112,7 +1112,7 @@ def is_interop_rewriteable?(o)
   end
 
   def self.concat(*args)
-    result = ''.dup
+    result = String.new
     args.each do |e|
       if e.instance_of?(Factory) && e.model_class <= LiteralString
         result << e[KEY_VALUE]

lib/puppet/pops/model/tree_dumper.rb

@@ -20,7 +20,7 @@ def indent
   end
 
   def format(x)
-    result = ""
+    result = String.new
     parts = format_r(x)
     parts.each_index do |i|
       if i > 0

lib/puppet/pops/parser/epp_support.rb

@@ -182,7 +182,7 @@ def scan(skip_leading=false)
       @skip_leading = skip_leading
 
       return nil if scanner.eos?
-      s = ""
+      s = String.new
       until scanner.eos?
         part = @scanner.scan_until(/(<%)|\z/)
         if @skip_leading

lib/puppet/pops/parser/evaluating_parser.rb

@@ -124,7 +124,7 @@ def quote(x)
   # @return [String] The quoted string
   #
   def self.quote(x)
-    escaped = '"'
+    escaped = String.new('"')
     p = nil
     x.each_char do |c|
       case p

lib/puppet/pops/parser/pn_parser.rb

@@ -217,7 +217,7 @@ def consume_identifier(s)
 
   def consume_string
     s = @pos
-    b = ''
+    b = String.new
     loop do
       c = next_cp
       case c

lib/puppet/pops/pn.rb

@@ -19,7 +19,7 @@ def ==(o)
   end
 
   def to_s
-    s = ''
+    s = String.new
     format(nil, s)
     s
   end

lib/puppet/pops/serialization/json_path.rb

@@ -10,7 +10,7 @@ module JsonPath
   #
   # @api private
   def self.to_json_path(path)
-    p = '$'
+    p = String.new('$')
     path.each do |seg|
       if seg.nil?
         p << '[null]'

lib/puppet/pops/serialization/to_data_converter.rb

@@ -63,7 +63,7 @@ def convert(value)
     private
 
     def path_to_s
-      s = @message_prefix || ''
+      s = String.new(@message_prefix || '')
       s << JsonPath.to_json_path(@path)[1..-1]
       s
     end

lib/puppet/pops/time/timespan.rb

@@ -544,7 +544,7 @@ def initialize(format, segments)
       end
 
       def format(timespan)
-        bld = timespan.negative? ? '-' : ''
+        bld = String.new(timespan.negative? ? '-' : '')
         @segments.each { |segment| segment.append_to(bld, timespan) }
         bld
       end
@@ -574,7 +574,7 @@ def regexp
       end
 
       def build_regexp
-        bld = '\A-?'
+        bld = String.new('\A-?')
         @segments.each { |segment| segment.append_regexp(bld) }
         bld << '\z'
         Regexp.new(bld)
@@ -612,7 +612,7 @@ def bad_format_specifier(format, start, position)
 
       def append_literal(bld, codepoint)
         if bld.empty? || !bld.last.is_a?(Format::LiteralSegment)
-          bld << Format::LiteralSegment.new(''.concat(codepoint))
+          bld << Format::LiteralSegment.new(String.new.concat(codepoint))
         else
           bld.last.concat(codepoint)
         end

lib/puppet/pops/types/ruby_generator.rb

@@ -59,7 +59,7 @@ def create_class(obj)
       if cls.nil?
         rp = key.resolved_parent
         parent_class = rp.is_a?(PObjectType) ? rp.implementation_class : Object
-        class_def = ''
+        class_def = String.new
         class_body(key, EMPTY_ARRAY, class_def)
         cls = Class.new(parent_class)
         cls.class_eval(class_def)
@@ -108,7 +108,7 @@ def module_definition(types, comment, *impl_subst)
     end
 
     # Create class definition of all contained types
-    bld = ''
+    bld = String.new
     start_module(common_prefix, comment, bld)
     class_names = []
     names_by_prefix.each_pair do |seg_array, index_and_name_array|

lib/puppet/pops/types/string_converter.rb

@@ -700,7 +700,7 @@ def string_PBooleanType(val_type, val, format_map, indentation)
   # Performs post-processing of literals to apply width and precision flags
   def apply_string_flags(f, literal_str)
     if f.left || f.width || f.prec
-      fmt = '%'
+      fmt = String.new('%')
       fmt << '-' if f.left
       fmt << f.width.to_s if f.width
       fmt << '.' << f.prec.to_s if f.prec
@@ -852,7 +852,7 @@ def puppet_quote(str, enforce_double_quotes = false)
     end
 
     # Assume that the string can be single quoted
-    bld = '\''
+    bld = String.new('\'')
     bld.force_encoding(str.encoding)
     escaped = false
     str.each_codepoint do |codepoint|
@@ -883,7 +883,7 @@ def puppet_quote(str, enforce_double_quotes = false)
   end
 
   def puppet_double_quote(str)
-    bld = '"'
+    bld = String.new('"')
     str.each_codepoint do |codepoint|
       case codepoint
       when 0x09
@@ -939,7 +939,7 @@ def string_PArrayType(val_type, val, format_map, indentation)
 
     case format.format
     when :a, :s, :p
-      buf = ''
+      buf = String.new
       if indentation.breaks?
         buf << "\n"
         buf << indentation.padding
@@ -1054,7 +1054,7 @@ def string_PHashType(val_type, val, format_map, indentation)
 
     when :h, :s, :p
       indentation = indentation.indenting(format.alt? || indentation.is_indenting?)
-      buf = ''
+      buf = String.new
       if indentation.breaks?
         buf << "\n"
         buf << indentation.padding