1 files changed, 59 insertions, 0 deletions
diff --git a/spec/migrations/add_unique_constraint_to_project_features_project_id_spec.rb b/spec/migrations/add_unique_constraint_to_project_features_project_id_spec.rb
new file mode 100644
index 00000000000..bf299b70a29
--- /dev/null
+++ b/spec/migrations/add_unique_constraint_to_project_features_project_id_spec.rb
@@ -0,0 +1,59 @@
+require 'spec_helper'
+require Rails.root.join('db', 'post_migrate', '20180511174224_add_unique_constraint_to_project_features_project_id.rb')
+
+describe AddUniqueConstraintToProjectFeaturesProjectId, :migration do
+  let(:namespaces) { table(:namespaces) }
+  let(:projects) { table(:projects) }
+  let(:features) { table(:project_features) }
+  let(:migration) { described_class.new }
+
+  describe '#up' do
+    before do
+      (1..3).each do |i|
+        namespaces.create(id: i, name: "ns-test-#{i}", path: "ns-test-i#{i}")
+        projects.create!(id: i, name: "test-#{i}", path: "test-#{i}", namespace_id: i)
+      end
+
+      features.create!(id: 1, project_id: 1)
+      features.create!(id: 2, project_id: 1)
+      features.create!(id: 3, project_id: 2)
+      features.create!(id: 4, project_id: 2)
+      features.create!(id: 5, project_id: 2)
+      features.create!(id: 6, project_id: 3)
+    end
+
+    it 'creates a unique index and removes duplicates' do
+      expect(migration.index_exists?(:project_features, :project_id, unique: false, name: 'index_project_features_on_project_id')).to be true
+
+      expect { migration.up }.to change { features.count }.from(6).to(3)
+
+      expect(migration.index_exists?(:project_features, :project_id, unique: true, name: 'index_project_features_on_project_id')).to be true
+      expect(migration.index_exists?(:project_features, :project_id, name: 'index_project_features_on_project_id_unique')).to be false
+
+      project_1_features = features.where(project_id: 1)
+      expect(project_1_features.count).to eq(1)
+      expect(project_1_features.first.id).to eq(2)
+
+      project_2_features = features.where(project_id: 2)
+      expect(project_2_features.count).to eq(1)
+      expect(project_2_features.first.id).to eq(5)
+
+      project_3_features = features.where(project_id: 3)
+      expect(project_3_features.count).to eq(1)
+      expect(project_3_features.first.id).to eq(6)
+    end
+  end
+
+  describe '#down' do
+    it 'restores the original index' do
+      migration.up
+
+      expect(migration.index_exists?(:project_features, :project_id, unique: true, name: 'index_project_features_on_project_id')).to be true
+
+      migration.down
+
+      expect(migration.index_exists?(:project_features, :project_id, unique: false, name: 'index_project_features_on_project_id')).to be true
+      expect(migration.index_exists?(:project_features, :project_id, name: 'index_project_features_on_project_id_old')).to be false
+    end
+  end
+end