1 files changed, 129 insertions, 0 deletions
diff --git a/spec/migrations/delete_inconsistent_internal_id_records_spec.rb b/spec/migrations/delete_inconsistent_internal_id_records_spec.rb
new file mode 100644
index 00000000000..8235dcacbef
--- /dev/null
+++ b/spec/migrations/delete_inconsistent_internal_id_records_spec.rb
@@ -0,0 +1,129 @@
+# rubocop:disable RSpec/FactoriesInMigrationSpecs
+require 'spec_helper'
+require Rails.root.join('db', 'post_migrate', '20180723130817_delete_inconsistent_internal_id_records.rb')
+
+describe DeleteInconsistentInternalIdRecords, :migration do
+  let!(:project1) { create(:project) }
+  let!(:project2) { create(:project) }
+  let!(:project3) { create(:project) }
+
+  let(:internal_id_query) { ->(project) { InternalId.where(usage: InternalId.usages[scope.to_s.tableize], project: project) } }
+  let(:scope_column) { :project }
+  let(:model_columns) { {} }
+
+  def at_least_times(how_often, &block)
+    [how_often, rand(how_often + 5)].max.times(&block)
+  end
+
+  let(:create_models) do
+    -> do
+      at_least_times(3) { create(scope, scope_column => project1) }
+      at_least_times(3) { create(scope, scope_column => project2) }
+      at_least_times(3) { create(scope, scope_column => project3) }
+    end
+  end
+
+  shared_examples_for 'deleting inconsistent internal_id records' do
+    before do
+      create_models.call()
+
+      internal_id_query.call(project1).first.tap do |iid|
+        iid.last_value = iid.last_value - 2
+        # This is an inconsistent record
+        iid.save!
+      end
+
+      internal_id_query.call(project3).first.tap do |iid|
+        iid.last_value = iid.last_value + 2
+        # This is a consistent record
+        iid.save!
+      end
+    end
+
+    it "deletes inconsistent issues" do
+      expect { migrate! }.to change { internal_id_query.call(project1).size }.from(1).to(0)
+    end
+
+    it "retains consistent issues" do
+      expect { migrate! }.not_to change { internal_id_query.call(project2).size }
+    end
+
+    it "retains consistent records, especially those with a greater last_value" do
+      expect { migrate! }.not_to change { internal_id_query.call(project3).size }
+    end
+  end
+
+  context 'for issues' do
+    let(:scope) { :issue }
+    it_behaves_like 'deleting inconsistent internal_id records'
+  end
+
+  context 'for merge_requests' do
+    let(:scope) { :merge_request }
+    let(:scope_column) { :target_project }
+
+    let(:create_models) do
+      -> do
+        at_least_times(3) { |i| create(scope, scope_column => project1, source_project: project1, source_branch: i.to_s) }
+        at_least_times(3) { |i| create(scope, scope_column => project2, source_project: project2, source_branch: i.to_s) }
+        at_least_times(3) { |i| create(scope, scope_column => project3, source_project: project3, source_branch: i.to_s) }
+      end
+    end
+
+    it_behaves_like 'deleting inconsistent internal_id records'
+  end
+
+  context 'for deployments' do
+    let(:scope) { :deployment }
+    it_behaves_like 'deleting inconsistent internal_id records'
+  end
+
+  context 'for milestones (by project)' do
+    let(:scope) { :milestone }
+    it_behaves_like 'deleting inconsistent internal_id records'
+  end
+
+  context 'for ci_pipelines' do
+    let(:scope) { :ci_pipeline }
+    it_behaves_like 'deleting inconsistent internal_id records'
+  end
+
+  context 'for milestones (by group)' do
+    # milestones (by group) is a little different than all of the other models
+    let!(:group1) { create(:group) }
+    let!(:group2) { create(:group) }
+    let!(:group3) { create(:group) }
+
+    let(:internal_id_query) { ->(group) { InternalId.where(usage: InternalId.usages['milestones'], namespace: group) } }
+
+    before do
+      at_least_times(3) { create(:milestone, group: group1) }
+      at_least_times(3) { create(:milestone, group: group2) }
+      at_least_times(3) { create(:milestone, group: group3) }
+
+      internal_id_query.call(group1).first.tap do |iid|
+        iid.last_value = iid.last_value - 2
+        # This is an inconsistent record
+        iid.save!
+      end
+
+      internal_id_query.call(group3).first.tap do |iid|
+        iid.last_value = iid.last_value + 2
+        # This is a consistent record
+        iid.save!
+      end
+    end
+
+    it "deletes inconsistent issues" do
+      expect { migrate! }.to change { internal_id_query.call(group1).size }.from(1).to(0)
+    end
+
+    it "retains consistent issues" do
+      expect { migrate! }.not_to change { internal_id_query.call(group2).size }
+    end
+
+    it "retains consistent records, especially those with a greater last_value" do
+      expect { migrate! }.not_to change { internal_id_query.call(group3).size }
+    end
+  end
+end