1 files changed, 55 insertions, 0 deletions
diff --git a/spec/migrations/replace_work_item_type_backfill_next_batch_strategy_spec.rb b/spec/migrations/replace_work_item_type_backfill_next_batch_strategy_spec.rb
new file mode 100644
index 00000000000..5e22fc06973
--- /dev/null
+++ b/spec/migrations/replace_work_item_type_backfill_next_batch_strategy_spec.rb
@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+require_migration!
+
+RSpec.describe ReplaceWorkItemTypeBackfillNextBatchStrategy, :migration do
+  describe '#up' do
+    it 'sets the new strategy for existing migrations' do
+      migrations = create_migrations(described_class::OLD_STRATEGY_CLASS, 2)
+
+      expect do
+        migrate!
+
+        migrations.each(&:reload)
+      end.to change { migrations.pluck(:batch_class_name).uniq }.from([described_class::OLD_STRATEGY_CLASS])
+                                                                .to([described_class::NEW_STRATEGY_CLASS])
+    end
+  end
+
+  describe '#down' do
+    it 'sets the old strategy for existing migrations' do
+      migrations = create_migrations(described_class::NEW_STRATEGY_CLASS, 2)
+
+      expect do
+        migrate!
+        schema_migrate_down!
+
+        migrations.each(&:reload)
+      end.to change { migrations.pluck(:batch_class_name).uniq }.from([described_class::NEW_STRATEGY_CLASS])
+                                                                .to([described_class::OLD_STRATEGY_CLASS])
+    end
+  end
+
+  def create_migrations(batch_class_name, count)
+    Array.new(2) { |index| create_background_migration(batch_class_name, [index]) }
+  end
+
+  def create_background_migration(batch_class_name, job_arguments)
+    migrations_table = table(:batched_background_migrations)
+
+    migrations_table.create!(
+      batch_class_name: batch_class_name,
+      job_class_name: described_class::JOB_CLASS_NAME,
+      max_value: 10,
+      batch_size: 5,
+      sub_batch_size: 1,
+      interval: 2.minutes,
+      table_name: :issues,
+      column_name: :id,
+      total_tuple_count: 10_000,
+      pause_ms: 100,
+      job_arguments: job_arguments
+    )
+  end
+end