Change dynamic String literals to String.new()

[gwhilts]

The following warning came up when running ptools in Ruby 3.4.1:

"...literal string will be frozen in the future"

It appears that in the future literal String assignments will be automatically frozen. (See https://bugs.ruby-lang.org/issues/20205). To avoid these warnings and prepare for the future, I changed the assignment of three dynamic Strings to use String.new() instead.

Warnings no longer appear. All unit tests pass.

[djberg96]

Thanks for the report!

[dastra-mak]

This got broken by 574ebb3.
As a result ruby 3.4 will print warnings: gems/ptools-1.5.1/lib/ptools.rb:433: warning: literal string will be frozen in the future (run with --debug-frozen-string-literal for more information)

[djberg96]

How is this warning manifesting for you? I don't see it when running specs or in irb.

[dastra-mak]

This occured in the context of a rails project. A model has the following method:

  def binary?
    File.binary?(file.path)
  end

This is called in a before_validation and results in the warning:

/home/user/.rbenv/versions/3.4.1/lib/ruby/gems/3.4.0/gems/ptools-1.5.1/lib/ptools.rb:433: warning: literal string will be frozen in the future
/home/user/.rbenv/versions/3.4.1/lib/ruby/gems/3.4.0/gems/ptools-1.5.1/lib/ptools.rb:433: info: the string was created here
/home/user/.rbenv/versions/3.4.1/lib/ruby/gems/3.4.0/gems/ptools-1.5.1/lib/ptools.rb:439: warning: literal string will be frozen in the future
/home/user/.rbenv/versions/3.4.1/lib/ruby/gems/3.4.0/gems/ptools-1.5.1/lib/ptools.rb:439: info: the string was created here
/home/user/.rbenv/versions/3.4.1/lib/ruby/gems/3.4.0/gems/ptools-1.5.1/lib/ptools.rb:468: warning: literal string will be frozen in the future
/home/user/.rbenv/versions/3.4.1/lib/ruby/gems/3.4.0/gems/ptools-1.5.1/lib/ptools.rb:468: info: the string was created here
/home/user/.rbenv/versions/3.4.1/lib/ruby/gems/3.4.0/gems/ptools-1.5.1/lib/ptools.rb:468: warning: literal string will be frozen in the future
/home/user/.rbenv/versions/3.4.1/lib/ruby/gems/3.4.0/gems/ptools-1.5.1/lib/ptools.rb:468: info: the string was created here

I got the warning with ruby 3.4.1 and 3.4.7.

I think that it is problematic to force encoding on a frozen string. To work around this, you could extract a constants that create byte-encoded copies of the literals, e.g.:

JPEG_JFIF_HEADER = "\xFF\xD8\xFF\xE0\x00\x10JFIF".b.freeze

[djberg96]

@dastra-mak #56