Add some specs

2 files changed, 55 insertions, 1 deletions

diff --git a/db/post_migrate/20190221234852_int4_pk_stage1of2_fill_column.rb b/db/post_migrate/20190221234852_int4_pk_stage1of2_fill_column.rb
index 4fa8c6d27af..4b073514013 100644
--- a/db/post_migrate/20190221234852_int4_pk_stage1of2_fill_column.rb
+++ b/db/post_migrate/20190221234852_int4_pk_stage1of2_fill_column.rb
@@ -1,7 +1,7 @@
 class Int4PkStage1of2FillColumn < ActiveRecord::Migration[5.0]
   include Gitlab::Database::MigrationHelpers
 
-  disable_ddl_transaction! 
+  disable_ddl_transaction!
 
   DOWNTIME = false
 
diff --git a/spec/migrations/int4_pk_stage1of2_fill_column_spec.rb b/spec/migrations/int4_pk_stage1of2_fill_column_spec.rb
new file mode 100644
index 00000000000..68d3c861493
--- /dev/null
+++ b/spec/migrations/int4_pk_stage1of2_fill_column_spec.rb
@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+require Rails.root.join('db', 'post_migrate', '20190221234852_int4_pk_stage1of2_fill_column.rb')
+
+describe Int4PkStage1of2FillColumn, :migration do
+  let(:users) { table(:users) }
+  let(:events) {table(:events) }
+
+  before do
+    Sidekiq::Worker.clear_all
+    stub_const("#{described_class.name}::BATCH_SIZE", 2)
+    @user = users.create!(projects_limit: 10, name: 'The User')
+  end
+
+  describe '#up' do
+    context 'events' do
+      it 'migrates id column values to id_new' do
+        3.times do
+          events.create!(author_id: @user.id, action: 'Open something')
+        end
+
+        migrate!
+
+        Event.all.limit(3).each do |event|
+          expect(event.id_new).to eq(event.id)
+        end
+      end
+
+      it 'schedules migration correctly' do
+        Sidekiq::Testing.fake! do
+          Timecop.freeze do
+            migration = described_class::MIGRATION
+            concurrency = described_class::CONCURRENCY
+            delay = described_class::DELAY
+            batch_size = described_class::BATCH_SIZE
+            batches_in_iteration = described_class::BATCHES_IN_ITERATION
+
+            migrate!
+
+            # Check how many times the migration has been scheduled
+            # deleting the last job that updates the table and then checking again
+            # Move to custom matcher?
+            concurrency.times do
+              expect(migration).to be_scheduled_delayed_migration(120, 'events', 'id', 'id_new', delay, batch_size, batches_in_iteration)
+              job_index = BackgroundMigrationWorker.jobs.index { |job| job['args'][1][0] == 'events' }
+              BackgroundMigrationWorker.jobs.delete_at(job_index)
+            end
+          end
+        end
+      end
+    end
+  end
+end