Fix third party hook for rails stats Thor command

[p8]

Legacy STATS_DIRECTORIES hook for Rake no longer works

STATS_DIRECTORIES is used by third parties to add directories to the statistics output. It's a global constant defined in a Rake file, that gets loaded anytime the Rake commands get loaded.

For example Rspec Rails adds spec directories in a prepended Rake task: https://github.com/rspec/rspec-rails/blob/8c17b4e5020a4d264e8a79e294c58b5c1ef2b005/lib/rspec/rails/tasks/rspec.rake#L43

Rake tasks only get loaded if no matching Thor task has been found. This means this constant is only available when the Rake commands have loaded.

New CodeStatistics.add_directory for Thor command

As the stats command has now been moved to a Thor task, calling bin/rails stats will no longer add directories to STATS_DIRECTORIES, as the Rake commands don't get loaded anymore.

To remove the dependency on Rake and avoid a global constant we can add an API to add directories: CodeStatistics.add_directory. STATS_DIRECTORIES is deprecated.

deprecate_constant couldn't be used here as that doesn't seem to work for the root namespace.

This was previously proposed/discussed in #49759, but I decided to resubmit it with the recent commit to make stats a Thor task.

Before

bin/rake stats adds custom directories (Model specs in this case):

bin/rake stats
DEPRECATION WARNING: `bin/rails stats` as rake task has been deprecated and will be removed in Rails 8.0.
Please use `bin/rails stats` as Rails command instead.

 (called from block in execute at .../gems/rake-13.1.0/lib/rake/task.rb:281)
DEPRECATION WARNING: `bin/rails stats` as rake task has been deprecated and will be removed in Rails 8.0.
Please use `bin/rails stats` as Rails command instead.

 (called from block in execute at .../gems/rake-13.1.0/lib/rake/task.rb:281)
+----------------------+--------+--------+---------+---------+-----+-------+
| Name                 |  Lines |    LOC | Classes | Methods | M/C | LOC/M |
+----------------------+--------+--------+---------+---------+-----+-------+
| Controllers          |      7 |      7 |       2 |       1 |   0 |     5 |
...
| System tests         |      0 |      0 |       0 |       0 |   0 |     0 |
| Model specs          |      5 |      4 |       0 |       0 |   0 |     0 |
+----------------------+--------+--------+---------+---------+-----+-------+
| Total                |    161 |    115 |      14 |       1 |   0 |   113 |
+----------------------+--------+--------+---------+---------+-----+-------+

bin/rails stats does not add custom directories (Model specs):

$ bin/rails stats
+----------------------+--------+--------+---------+---------+-----+-------+
| Name                 |  Lines |    LOC | Classes | Methods | M/C | LOC/M |
+----------------------+--------+--------+---------+---------+-----+-------+
| Controllers          |      7 |      7 |       2 |       1 |   0 |     5 |
...
| System tests         |      0 |      0 |       0 |       0 |   0 |     0 |
+----------------------+--------+--------+---------+---------+-----+-------+
| Total                |    156 |    111 |      14 |       1 |   0 |   109 |
+----------------------+--------+--------+---------+---------+-----+-------+

After

bin/rake stats adds directories (Model specs).

$ bin/rake stats
DEPRECATION WARNING: `STATS_DIRECTORIES` is deprecated and will be removed in Rails 8.1! Use `Rails.application.config.code_statistics.directories` instead. (called from block in execute at .../gems/rake-13.1.0/lib/rake/task.rb:281)
DEPRECATION WARNING: `bin/rake stats` as rake task has been deprecated and will be removed in Rails 8.1.
Please use `bin/rails stats` as Rails command instead.

 (called from block in execute at .../gems/rake-13.1.0/lib/rake/task.rb:281)
DEPRECATION WARNING: `bin/rake stats` as rake task has been deprecated and will be removed in Rails 8.1.
Please use `bin/rails stats` as Rails command instead.

 (called from block in execute at .../gems/rake-13.1.0/lib/rake/task.rb:281)
+----------------------+--------+--------+---------+---------+-----+-------+
| Name                 |  Lines |    LOC | Classes | Methods | M/C | LOC/M |
+----------------------+--------+--------+---------+---------+-----+-------+
| Controllers          |      7 |      7 |       2 |       1 |   0 |     5 |
...
| System tests         |      0 |      0 |       0 |       0 |   0 |     0 |
| Model specs          |      5 |      4 |       0 |       0 |   0 |     0 |
+----------------------+--------+--------+---------+---------+-----+-------+
| Total                |    161 |    115 |      14 |       1 |   0 |   113 |
+----------------------+--------+--------+---------+---------+-----+-------+

bin/rails stats adds directories added in a Raills.application.config.after_initialize block.

$ bin/rails stats
+----------------------+--------+--------+---------+---------+-----+-------+
| Name                 |  Lines |    LOC | Classes | Methods | M/C | LOC/M |
+----------------------+--------+--------+---------+---------+-----+-------+
| Controllers          |      7 |      7 |       2 |       1 |   0 |     5 |
...
| System tests         |      0 |      0 |       0 |       0 |   0 |     0 |
| Model specs          |      5 |      4 |       0 |       0 |   0 |     0 |
+----------------------+--------+--------+---------+---------+-----+-------+
| Total                |    161 |    115 |      14 |       1 |   0 |   113 |
+----------------------+--------+--------+---------+---------+-----+-------+
....

Checklist

Before submitting the PR make sure the following are checked:

• This Pull Request is related to one change. Unrelated changes should be opened in separate PRs.
• Commit message has a detailed description of what changed and why. If this PR fixes a related issue include it in the commit message. Ex: [Fix #issue-number]
• Tests are added or updated if you fix a bug or add a feature.
• CHANGELOG files are updated for the changed libraries if there is a behavior change or additional feature. Minor bug fixes and documentation changes should not be included.

[p8]

Instead of having a config setting that requires a booted application, it would probably be better to have a clear API on CodeStatistics:

    CodeStatistics.add_directory("My Directory", "path/to/dir")

[p8]

I've changed the PR to use CodeStatistics.add_directory instead of config.code_statistics.directories.

[rafaelfranca]

This class is nodoc, we can't add a method we expect people to use on it and keep it nodoc.

[rafaelfranca]

Lets remove the nodoc and document this class

[p8]

If we are going to document this class should it also be namespaced under Rails:: like most classes in railties/lib/rails?
Otherwise we'll have a top level constant CodeStatistics

[zzak]

@p8 I think this should be inside the Rails:: constant, to match the path
Edit: Fixed in #52706 (Sorry I'm catching up)

[p8]

🙂

[rafaelfranca]

Lets remove the nodoc and document this class