Fix irreversible upgrade migration (rails#44)

Author: thiagoyoussef

bench/db/migrate/20240912235943_create_compact_channel.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 class CreateCompactChannel < ActiveRecord::Migration[7.2]
-  def change
+  def up
     change_column :solid_cable_messages, :channel, :binary, limit: 1024, null: false
     add_column :solid_cable_messages, :channel_hash, :integer, limit: 8, if_not_exists: true
     add_index :solid_cable_messages, :channel_hash, if_not_exists: true
@@ -12,4 +12,10 @@ def change
       msg.update(channel_hash: SolidCable::Message.channel_hash_for(msg.channel))
     end
   end
+
+  def down
+    change_column :solid_cable_messages, :channel, :text
+    remove_column :solid_cable_messages, :channel_hash, if_exists: true
+    change_column :solid_cable_messages, :payload, :text
+  end
 end

lib/generators/solid_cable/update/templates/db/migrate/create_compact_channel.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 class CreateCompactChannel < ActiveRecord::Migration[7.2]
-  def change
+  def up
     change_column :solid_cable_messages, :channel, :binary, limit: 1024, null: false
     add_column :solid_cable_messages, :channel_hash, :integer, limit: 8, if_not_exists: true
     add_index :solid_cable_messages, :channel_hash, if_not_exists: true
@@ -11,4 +11,10 @@ def change
       msg.update(channel_hash: SolidCable::Message.channel_hash_for(msg.channel))
     end
   end
+
+  def down
+    change_column :solid_cable_messages, :channel, :text
+    remove_column :solid_cable_messages, :channel_hash, if_exists: true
+    change_column :solid_cable_messages, :payload, :text
+  end
 end