Make it possible to provide schema version in tests

spec/lib/gitlab/background_migration/migrate_events_to_push_event_payloads_spec.rb

@@ -210,7 +210,11 @@ describe Gitlab::BackgroundMigration::MigrateEventsToPushEventPayloads::Event do
   end
 end
 
-describe Gitlab::BackgroundMigration::MigrateEventsToPushEventPayloads do
+##
+# The background migration relies on a temporary table, hence we're migrating
+# to a specific version of the database where said table is still present.
+#
+describe Gitlab::BackgroundMigration::MigrateEventsToPushEventPayloads, :migration, schema: 20170608152748 do
   let(:migration) { described_class.new }
   let(:project) { create(:project_empty_repo) }
   let(:author) { create(:user) }
@@ -229,21 +233,6 @@ describe Gitlab::BackgroundMigration::MigrateEventsToPushEventPayloads do
     )
   end
 
-  # The background migration relies on a temporary table, hence we're migrating
-  # to a specific version of the database where said table is still present.
-  before :all do
-    ActiveRecord::Migration.verbose = false
-
-    ActiveRecord::Migrator
-      .migrate(ActiveRecord::Migrator.migrations_paths, 20170608152748)
-  end
-
-  after :all do
-    ActiveRecord::Migrator.migrate(ActiveRecord::Migrator.migrations_paths)
-
-    ActiveRecord::Migration.verbose = true
-  end
-
   describe '#perform' do
     it 'returns if data should not be migrated' do
       allow(migration).to receive(:migrate?).and_return(false)

spec/spec_helper.rb

@@ -136,17 +136,12 @@ RSpec.configure do |config|
     Sidekiq.redis(&:flushall)
   end
 
-  config.before(:example, :migration) do
-    ActiveRecord::Migrator
-      .migrate(migrations_paths, previous_migration.version)
-
-    reset_column_in_migration_models
+  config.before(:context, :migration) do
+    schema_migrate_down!
   end
 
-  config.after(:example, :migration) do
-    ActiveRecord::Migrator.migrate(migrations_paths)
-
-    reset_column_in_migration_models
+  config.after(:context, :migration) do
+    schema_migrate_up!
   end
 
   config.around(:each, :nested_groups) do |example|

spec/support/migrations_helpers.rb

@@ -31,6 +31,21 @@ module MigrationsHelpers
     end
   end
 
+  def migration_schema_version
+    self.class.metadata[:schema] || previous_migration.version
+  end
+
+  def schema_migrate_down!
+    ActiveRecord::Migrator
+      .migrate(migrations_paths, migration_schema_version)
+    reset_column_in_migration_models
+  end
+
+  def schema_migrate_up!
+    ActiveRecord::Migrator.migrate(migrations_paths)
+    reset_column_in_migration_models
+  end
+
   def migrate!
     ActiveRecord::Migrator.up(migrations_paths) do |migration|
       migration.name == described_class.name