1 files changed, 104 insertions, 0 deletions
diff --git a/spec/lib/gitlab/background_migration/backfill_project_member_namespace_id_spec.rb b/spec/lib/gitlab/background_migration/backfill_project_member_namespace_id_spec.rb
new file mode 100644
index 00000000000..ca7ca41a33e
--- /dev/null
+++ b/spec/lib/gitlab/background_migration/backfill_project_member_namespace_id_spec.rb
@@ -0,0 +1,104 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::BackgroundMigration::BackfillProjectMemberNamespaceId, :migration, schema: 20220516054011 do
+  let(:migration) do
+    described_class.new(start_id: 1, end_id: 10,
+                        batch_table: table_name, batch_column: batch_column,
+                        sub_batch_size: sub_batch_size, pause_ms: pause_ms,
+                        connection: ApplicationRecord.connection)
+  end
+
+  let(:members_table) { table(:members) }
+  let(:projects_table) { table(:projects) }
+  let(:namespaces_table) { table(:namespaces) }
+
+  let(:table_name) { 'members' }
+  let(:batch_column) { :id }
+  let(:sub_batch_size) { 100 }
+  let(:pause_ms) { 0 }
+
+  subject(:perform_migration) do
+    migration.perform
+  end
+
+  before do
+    namespaces_table.create!(id: 201, name: 'group1', path: 'group1', type: 'Group')
+    namespaces_table.create!(id: 202, name: 'group2', path: 'group2', type: 'Group')
+    namespaces_table.create!(id: 300, name: 'project-namespace-1', path: 'project-namespace-1-path', type: 'Project')
+    namespaces_table.create!(id: 301, name: 'project-namespace-2', path: 'project-namespace-2-path', type: 'Project')
+    namespaces_table.create!(id: 302, name: 'project-namespace-3', path: 'project-namespace-3-path', type: 'Project')
+
+    projects_table.create!(id: 100, name: 'project1', path: 'project1', namespace_id: 202, project_namespace_id: 300)
+    projects_table.create!(id: 101, name: 'project2', path: 'project2', namespace_id: 202, project_namespace_id: 301)
+    projects_table.create!(id: 102, name: 'project3', path: 'project3', namespace_id: 202, project_namespace_id: 302)
+
+    # project1, no member namespace (fill in)
+    members_table.create!(id: 1, source_id: 100,
+                          source_type: 'Project', type: 'ProjectMember',
+                          member_namespace_id: nil, access_level: 10, notification_level: 3)
+    # bogus source id, no member namespace id (do nothing)
+    members_table.create!(id: 2, source_id: non_existing_record_id,
+                          source_type: 'Project', type: 'ProjectMember',
+                          member_namespace_id: nil, access_level: 10, notification_level: 3)
+    # project3, existing member namespace id (do nothing)
+    members_table.create!(id: 3, source_id: 102,
+                          source_type: 'Project', type: 'ProjectMember',
+                          member_namespace_id: 300, access_level: 10, notification_level: 3)
+
+    # Group memberships (do not change)
+    # group1, no member namespace (do nothing)
+    members_table.create!(id: 4, source_id: 201,
+                          source_type: 'Namespace', type: 'GroupMember',
+                          member_namespace_id: nil, access_level: 10, notification_level: 3)
+    # group2, existing member namespace (do nothing)
+    members_table.create!(id: 5, source_id: 202,
+                          source_type: 'Namespace', type: 'GroupMember',
+                          member_namespace_id: 201, access_level: 10, notification_level: 3)
+
+    # Project Namespace memberships (do not change)
+    # project namespace, existing member namespace (do nothing)
+    members_table.create!(id: 6, source_id: 300,
+                          source_type: 'Namespace', type: 'ProjectNamespaceMember',
+                          member_namespace_id: 201, access_level: 10, notification_level: 3)
+    # project namespace, not member namespace (do nothing)
+    members_table.create!(id: 7, source_id: 301,
+                          source_type: 'Namespace', type: 'ProjectNamespaceMember',
+                          member_namespace_id: 201, access_level: 10, notification_level: 3)
+  end
+
+  it 'backfills `member_namespace_id` for the selected records', :aggregate_failures do
+    expect(members_table.where(type: 'ProjectMember', member_namespace_id: nil).count).to eq 2
+    expect(members_table.where(type: 'GroupMember', member_namespace_id: nil).count).to eq 1
+
+    queries = ActiveRecord::QueryRecorder.new do
+      perform_migration
+    end
+
+    # rubocop:disable Layout/LineLength
+    expect(queries.count).to eq(3)
+    expect(members_table.where(type: 'ProjectMember', member_namespace_id: nil).count).to eq 1 # just the bogus one
+    expect(members_table.where(type: 'ProjectMember').pluck(:member_namespace_id)).to match_array([nil, 300, 300])
+    expect(members_table.where(type: 'GroupMember', member_namespace_id: nil).count).to eq 1
+    expect(members_table.where(type: 'GroupMember').pluck(:member_namespace_id)).to match_array([nil, 201])
+    # rubocop:enable Layout/LineLength
+  end
+
+  it 'tracks timings of queries' do
+    expect(migration.batch_metrics.timings).to be_empty
+
+    expect { perform_migration }.to change { migration.batch_metrics.timings }
+  end
+
+  context 'when given a negative pause_ms' do
+    let(:pause_ms) { -9 }
+    let(:sub_batch_size) { 2 }
+
+    it 'uses 0 as a floor for pause_ms' do
+      expect(migration).to receive(:sleep).with(0)
+
+      perform_migration
+    end
+  end
+end