1 files changed, 65 insertions, 0 deletions
diff --git a/spec/migrations/20220124130028_dedup_runner_projects_spec.rb b/spec/migrations/20220124130028_dedup_runner_projects_spec.rb
new file mode 100644
index 00000000000..2698af6f6f5
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+++ b/spec/migrations/20220124130028_dedup_runner_projects_spec.rb
@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+require Rails.root.join('db', 'post_migrate', '20220124130028_dedup_runner_projects.rb')
+
+RSpec.describe DedupRunnerProjects, :migration, schema: 20220120085655 do
+  let(:namespaces) { table(:namespaces) }
+  let(:projects) { table(:projects) }
+  let(:runners) { table(:ci_runners) }
+  let(:runner_projects) { table(:ci_runner_projects) }
+
+  let!(:namespace) { namespaces.create!(name: 'foo', path: 'foo') }
+  let!(:project) { projects.create!(namespace_id: namespace.id) }
+  let!(:project_2) { projects.create!(namespace_id: namespace.id) }
+  let!(:runner) { runners.create!(runner_type: 'project_type') }
+  let!(:runner_2) { runners.create!(runner_type: 'project_type') }
+  let!(:runner_3) { runners.create!(runner_type: 'project_type') }
+
+  let!(:duplicated_runner_project_1) { runner_projects.create!(runner_id: runner.id, project_id: project.id) }
+  let!(:duplicated_runner_project_2) { runner_projects.create!(runner_id: runner.id, project_id: project.id) }
+  let!(:duplicated_runner_project_3) { runner_projects.create!(runner_id: runner_2.id, project_id: project_2.id) }
+  let!(:duplicated_runner_project_4) { runner_projects.create!(runner_id: runner_2.id, project_id: project_2.id) }
+
+  let!(:non_duplicated_runner_project) { runner_projects.create!(runner_id: runner_3.id, project_id: project.id) }
+
+  it 'deduplicates ci_runner_projects table' do
+    expect { migrate! }.to change { runner_projects.count }.from(5).to(3)
+  end
+
+  it 'merges `duplicated_runner_project_1` with `duplicated_runner_project_2`', :aggregate_failures do
+    migrate!
+
+    expect(runner_projects.where(id: duplicated_runner_project_1.id)).not_to(exist)
+
+    merged_runner_projects = runner_projects.find_by(id: duplicated_runner_project_2.id)
+
+    expect(merged_runner_projects).to be_present
+    expect(merged_runner_projects.created_at).to be_like_time(duplicated_runner_project_1.created_at)
+    expect(merged_runner_projects.created_at).to be_like_time(duplicated_runner_project_2.created_at)
+  end
+
+  it 'merges `duplicated_runner_project_3` with `duplicated_runner_project_4`', :aggregate_failures do
+    migrate!
+
+    expect(runner_projects.where(id: duplicated_runner_project_3.id)).not_to(exist)
+
+    merged_runner_projects = runner_projects.find_by(id: duplicated_runner_project_4.id)
+
+    expect(merged_runner_projects).to be_present
+    expect(merged_runner_projects.created_at).to be_like_time(duplicated_runner_project_3.created_at)
+    expect(merged_runner_projects.created_at).to be_like_time(duplicated_runner_project_4.created_at)
+  end
+
+  it 'does not change non duplicated records' do
+    expect { migrate! }.not_to change { non_duplicated_runner_project.reload.attributes }
+  end
+
+  it 'does nothing when there are no runner projects' do
+    runner_projects.delete_all
+
+    migrate!
+
+    expect(runner_projects.count).to eq(0)
+  end
+end