Bug #20920: When loading a file, __FILE__ gets relative paths expanded only when they start with "./"

• Status: Open
• Assignee: -
• Target version: -
• ruby -v: ruby 3.3.6 (2024-11-05 revision 75015d4c1f) [arm64-darwin23]
• Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN

[deivid (David Rodríguez)]

$ cat foo.rb
puts __FILE__

$ ruby foo.rb              
foo.rb

$ ruby ./foo.rb            
./foo.rb

$ ruby -e 'load "foo.rb"'  
foo.rb

$ ruby -e 'load "./foo.rb"'
/full/path/to/foo.rb

More than an issue, this is mainly a question. In principle, it seems more consistent to me to either expand or not expand, but this is not causing real issues for me. I just want to figure out what to do with one pending spec in Bundler (https://github.com/rubygems/rubygems/blob/cd65092deb3168759820c613ecbc54cd9e06d46f/bundler/spec/commands/exec_spec.rb#L1023-L1028).

[deivid (David Rodríguez)]

• Description updated (diff)
• ruby -v set to ruby 3.3.6 (2024-11-05 revision 75015d4c1f) [arm64-darwin23]

[Dan0042 (Daniel DeLorme)]

It's interesting that this highlights the only case where load searches in a different path than require

if path is absolute
  load/require absolute path --> __FILE__ is absolute
elsif path starts with "." or ".."
  load/require relative to pwd --> __FILE__ is expanded to absolute
else
  load/require relative to each $LOAD_PATH --> __FILE__ is expanded to absolute
  if above not found, load (but not require) relative to pwd --> __FILE__ is NOT expanded to absolute
end

[vo.x (Vit Ondruch)]

This is very related to #16978

And all this started with introduction of require_relative and it is a mess since then. IMHO, the path expansion is evil. It prevents usage of symlinks, it is troublesome with modifications of $LOAD_PATH, etc.

[deivid (David Rodríguez)]

For what it's worth, this is not currently causing any issues in Bundler/RubyGems that I know of, so I changed the pending spec to track current Ruby's behavior and move on. From my side, this can be closed, but of course if Ruby maintainers think that it's worth and possible to bring more consistency here, I fully support that too.

[mame (Yusuke Endoh)]

Discussed at the dev meeting. @matz (Yukihiro Matsumoto) suggested that we try modifying it so that only the load "foo.rb" case is a full path, and leave the other cases as is.

$ ruby foo.rb
foo.rb   # This should be kept

$ ruby ./foo.rb
./foo.rb # This should be kept

$ ruby -e 'load "foo.rb"'
foo.rb # This should be a full path

$ ruby -e 'load "./foo.rb"'
/full/path/to/foo.rb # This should be kept