1 files changed, 35 insertions, 0 deletions
diff --git a/spec/lib/gitlab/background_migration/populate_topics_total_projects_count_cache_spec.rb b/spec/lib/gitlab/background_migration/populate_topics_total_projects_count_cache_spec.rb
new file mode 100644
index 00000000000..8e07b43f5b9
--- /dev/null
+++ b/spec/lib/gitlab/background_migration/populate_topics_total_projects_count_cache_spec.rb
@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::BackgroundMigration::PopulateTopicsTotalProjectsCountCache, schema: 20211006060436 do
+  it 'correctly populates total projects count cache' do
+    namespaces = table(:namespaces)
+    projects = table(:projects)
+    topics = table(:topics)
+    project_topics = table(:project_topics)
+
+    group = namespaces.create!(name: 'group', path: 'group')
+    project_1 = projects.create!(namespace_id: group.id)
+    project_2 = projects.create!(namespace_id: group.id)
+    project_3 = projects.create!(namespace_id: group.id)
+    topic_1 = topics.create!(name: 'Topic1')
+    topic_2 = topics.create!(name: 'Topic2')
+    topic_3 = topics.create!(name: 'Topic3')
+    topic_4 = topics.create!(name: 'Topic4')
+
+    project_topics.create!(project_id: project_1.id, topic_id: topic_1.id)
+    project_topics.create!(project_id: project_1.id, topic_id: topic_3.id)
+    project_topics.create!(project_id: project_2.id, topic_id: topic_3.id)
+    project_topics.create!(project_id: project_1.id, topic_id: topic_4.id)
+    project_topics.create!(project_id: project_2.id, topic_id: topic_4.id)
+    project_topics.create!(project_id: project_3.id, topic_id: topic_4.id)
+
+    subject.perform(topic_1.id, topic_4.id)
+
+    expect(topic_1.reload.total_projects_count).to eq(1)
+    expect(topic_2.reload.total_projects_count).to eq(0)
+    expect(topic_3.reload.total_projects_count).to eq(2)
+    expect(topic_4.reload.total_projects_count).to eq(3)
+  end
+end