Merge pull request #3109 from nebulab/spaghetticode/safer-migration-2…

…0180710170104

Remove destructive actions from migration 20180710170104

core/db/migrate/20180710170104_create_spree_store_credit_reasons_table.rb

@@ -21,22 +21,35 @@ def up
       StoreCreditReason.create!(name: update_reason.name)
     end
 
-    drop_table :spree_store_credit_update_reasons
-    rename_column :spree_store_credit_events, :update_reason_id, :store_credit_reason_id
+    add_column :spree_store_credit_events, :store_credit_reason_id, :integer
+    execute "update spree_store_credit_events set store_credit_reason_id = update_reason_id"
+
+    # TODO: table spree_store_credit_update_reasons and column
+    # column spree_store_credit_update_reasons.update_reason_id
+    # must be dropped in a future Solidus release
   end
 
   def down
-    create_table :spree_store_credit_update_reasons do |t|
-      t.string :name
-
-      t.timestamps
+    # This table and column  may not exist anymore as another irreversible
+    # migration may have removed it later. They must be added back or the
+    # `up` method would fail
+    unless table_exists? :spree_store_credit_update_reasons
+      create_table :spree_store_credit_update_reasons do |t|
+        t.string :name
+
+        t.timestamps
+      end
+
+      unless column_exists? :spree_store_credit_events, :update_reason_id
+        add_column :spree_store_credit_events, :update_reason_id, :integer
+      end
     end
 
     StoreCreditReason.all.each do |store_credit_reason|
       StoreCreditUpdateReason.create!(name: store_credit_reason.name)
     end
 
     drop_table :spree_store_credit_reasons
-    rename_column :spree_store_credit_events, :store_credit_reason_id, :update_reason_id
+    remove_column :spree_store_credit_events, :store_credit_reason_id
   end
 end