[Fix #591] Add change_column check to Rails/ReversibleMigration

`change_column` is not on the list of the migration definitions supported by the `change` method. This is easy to miss as there are a couple `change_column_*` methods that are supported.

When trying to rollback a migration that uses `change_column` in the `change` method, the rollback will fail.  This change adds the check to `Rails/ReversibleMigration`.

Author: mattmccormick

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## master (unreleased)
 
+### Changes
+
+* [#591](https://github.com/rubocop/rubocop-rails/issues/591): Add `change_column` to `Rails/ReversibleMigration`. ([@mattmccormick][])
+
 ## 2.12.4 (2021-10-16)
 
 ### Bug fixes
@@ -484,3 +488,4 @@
 [@theunraveler]: https://github.com/theunraveler
 [@pirj]: https://github.com/pirj
 [@vitormd]: https://github.com/vitormd
+[@mattmccormick]: https://github.com/mattmccormick

lib/rubocop/cop/rails/reversible_migration.rb

@@ -179,7 +179,7 @@ class ReversibleMigration < Base
         MSG = '%<action>s is not reversible.'
 
         def_node_matcher :irreversible_schema_statement_call, <<~PATTERN
-          (send nil? ${:execute :remove_belongs_to} ...)
+          (send nil? ${:execute :remove_belongs_to :change_column} ...)
         PATTERN
 
         def_node_matcher :drop_table_call, <<~PATTERN

spec/rubocop/cop/rails/reversible_migration_spec.rb

@@ -110,6 +110,16 @@ def change
     RUBY
   end
 
+  context 'change_column' do
+    it_behaves_like 'offense', 'change_column', <<~RUBY
+      change_column(:posts, :state, :string)
+    RUBY
+
+    it_behaves_like 'offense', 'change_column', <<~RUBY
+      change_column(:posts, :state, :string, null: false)
+    RUBY
+  end
+
   context 'change_column_default' do
     it_behaves_like 'accepts',
                     'change_column_default(with :from and :to)', <<-RUBY