Add rails-diff dotfiles command

Co-authored-by: Steve Redka <[email protected]>

Author: MatheusRich

CHANGELOG.md

@@ -1,6 +1,7 @@
 ## [Unreleased]
 
 - Add `--only` option to only include specific files or directories in the diff.
+- Add `rails-diff dotfiles` to compare dotfiles (configuration files) in the repository.
 - [BUGFIX] --fail-on-diff wasn't aborting with errors on diff.
 
 ## [0.5.0] - 2025-03-10

README.md

@@ -67,7 +67,14 @@ rails-diff generated scaffold Post --fail-on-diff
 rails-diff generated authentication --commit 7df1b8
 ```
 
-### Options
+### Compare dotfiles (configuration files)
+
+```bash
+# Compare configuration files like .gitignore, .rspec, .rubocop.yml
+rails-diff dotfiles
+```
+
+### Global Options
 
 #### --fail-on-diff
 

lib/rails/diff/cli.rb

@@ -26,6 +26,12 @@ def file(*files)
 
         options[:fail_on_diff] ? abort(diff) : puts(diff)
       end
+
+      desc "dotfiles", "Compare dotfiles in your repository with the ones generated by Rails"
+      def dotfiles
+        dotfiles = `git ls-files --cached --others --exclude-standard -- '.*'`.split("\n")
+
+        file(*dotfiles)
       end
 
       desc "generated GENERATOR [args]", "Compare files that would be created by a Rails generator"