Warn on command-line with permalink conflict

[SeekingMeaning]

This is a 🙋 feature or enhancement.

Summary

This prints a warning for permalink conflict when running jekyll serve

Example output:

Configuration file: ~/permalink-conflict-test/_config.yml
            Source: ~/permalink-conflict-test
       Destination: ~/permalink-conflict-test/_site
 Incremental build: disabled. Enable with --incremental
      Generating... 
       Jekyll Feed: Generating feed for posts
          Conflict: The URL '~/permalink-conflict-test/_site/z.html' is the destination for the following pages: b.markdown, c.markdown
                    done in 0.324 seconds.
 Auto-regeneration: enabled for '~/permalink-conflict-test'
    Server address: http://127.0.0.1:4000/
  Server running... press ctrl-c to stop.

Context

Closes #6207

[ashmaroli]

@SeekingMeaning Thank you for submitting this pull request.
I'd like some changes to be made, however:

• The Jekyll::Commands::Doctor.conflicting_urls is already a public class method. Why not call it directly from within the class Site instead of moving it into a new utility module?

  # lib/jekyll/site.rb
  
  def process
    ...
    Jekyll::Commands::Doctor.conflicting_urls(self)
  end

  The benefits being:
  • use of existing implementation — no need for additional tests.
  • doesn't break semver principle by the Doctor command class not being able to call the method directly from outside the class.
• Secondly, how about issuing the warning as part of the Jekyll::Site#write method call instead of after writing all files?

[ashmaroli]

Thanks for the changes.

..as part of the Jekyll::Site#write method call instead of after writing all files?

This has still not been resolved, though. The focus being instead of after writing all files.
I recommend that the warning be issued before the call to block attached to each_site_file.

[ashmaroli]

LGTM!

[ashmaroli]

@SeekingMeaning If you're interested, you can try and add a Cucumber based test to take this up to 💯
However, its totally your call and as far as I'm concerned, the current diff is sufficient for a merge.
Thank you for your contribution.

[SeekingMeaning]

Hmm where would be a good place to add the test?

[ashmaroli]

where would be a good place to add the test?

features/permalinks.feature

[ashmaroli]

💯

[DirtyF]

Awesome, thanks!

[ashmaroli]

@jekyllbot: merge +minor