[Fix #546] Exclude app/models by default for Rails/ContentTag

Fixes #546

This PR excludes `app/models` by default for `Rails/ContentTag`.
Because it prevents false positives for `tag` calls to `has_one: tag`.
No helpers are used in normal models.

Author: koic

changelog/change_exclude_models_by_default_for_rails_content_tag.md

@@ -0,0 +1 @@
+* [#546](https://github.com/rubocop/rubocop-rails/issues/546): Exclude `app/models` by default for `Rails/ContentTag`. ([@koic][])

config/default.yml

@@ -189,6 +189,9 @@ Rails/ContentTag:
   Enabled: true
   VersionAdded: '2.6'
   VersionChanged: '2.12'
+  # This `Exclude` config prevents false positives for `tag` calls to `has_one: tag`. No helpers are used in normal models.
+  Exclude:
+    - app/models/**/*.rb
 
 Rails/CreateTableWithTimestamps:
   Description: >-

docs/modules/ROOT/pages/cops_rails.adoc

@@ -845,6 +845,16 @@ tag.br(class: 'classname')
 tag(name, class: 'classname')
 ----
 
+=== Configurable attributes
+
+|===
+| Name | Default value | Configurable values
+
+| Exclude
+| `app/models/**/*.rb`
+| Array
+|===
+
 === References
 
 * https://github.com/rubocop/rubocop-rails/issues/260