1 files changed, 34 insertions, 0 deletions
diff --git a/db/migrate/20220613110711_migrate_custom_filters.rb b/db/migrate/20220613110711_migrate_custom_filters.rb
new file mode 100644
index 000000000..ea6a9b8c6
--- /dev/null
+++ b/db/migrate/20220613110711_migrate_custom_filters.rb
@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+class MigrateCustomFilters < ActiveRecord::Migration[6.1]
+  def up
+    # Preserve IDs as much as possible to not confuse existing clients.
+    # As long as this migration is irreversible, we do not have to deal with conflicts.
+    safety_assured do
+      execute <<-SQL.squish
+        INSERT INTO custom_filter_keywords (id, custom_filter_id, keyword, whole_word, created_at, updated_at)
+        SELECT id, id, phrase, whole_word, created_at, updated_at
+        FROM custom_filters
+      SQL
+    end
+  end
+
+  def down
+    # Copy back changes from custom filters guaranteed to be from the old API
+    safety_assured do
+      execute <<-SQL.squish
+        UPDATE custom_filters
+        SET phrase = custom_filter_keywords.keyword, whole_word = custom_filter_keywords.whole_word
+        FROM custom_filter_keywords
+        WHERE custom_filters.id = custom_filter_keywords.id AND custom_filters.id = custom_filter_keywords.custom_filter_id
+      SQL
+    end
+
+    # Drop every keyword as we can't safely provide a 1:1 mapping
+    safety_assured do
+      execute <<-SQL.squish
+        TRUNCATE custom_filter_keywords RESTART IDENTITY
+      SQL
+    end
+  end
+end