1 files changed, 143 insertions, 0 deletions
diff --git a/spec/services/terraform/remote_state_handler_spec.rb b/spec/services/terraform/remote_state_handler_spec.rb
new file mode 100644
index 00000000000..f4e1831b2e8
--- /dev/null
+++ b/spec/services/terraform/remote_state_handler_spec.rb
@@ -0,0 +1,143 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Terraform::RemoteStateHandler do
+  let_it_be(:project) { create(:project) }
+  let_it_be(:user) { create(:user) }
+
+  describe '#find_with_lock' do
+    context 'without a state name' do
+      subject { described_class.new(project, user) }
+
+      it 'raises an exception' do
+        expect { subject.find_with_lock }.to raise_error(ArgumentError)
+      end
+    end
+
+    context 'with a state name' do
+      subject { described_class.new(project, user, name: 'state') }
+
+      context 'with no matching state' do
+        it 'raises an exception' do
+          expect { subject.find_with_lock }.to raise_error(ActiveRecord::RecordNotFound)
+        end
+      end
+
+      context 'with a matching state' do
+        let!(:state) { create(:terraform_state, project: project, name: 'state') }
+
+        it 'returns the state' do
+          expect(subject.find_with_lock).to eq(state)
+        end
+      end
+    end
+  end
+
+  describe '#create_or_find!' do
+    it 'requires passing a state name' do
+      handler = described_class.new(project, user)
+
+      expect { handler.create_or_find! }.to raise_error(ArgumentError)
+    end
+
+    it 'allows to create states with same name in different projects' do
+      project_b =  create(:project)
+
+      state_a = described_class.new(project, user, name: 'my-state').create_or_find!
+      state_b = described_class.new(project_b, user, name: 'my-state').create_or_find!
+
+      expect(state_a).to be_persisted
+      expect(state_b).to be_persisted
+      expect(state_a.id).not_to eq state_b.id
+    end
+
+    it 'loads the same state upon subsequent call in the project scope' do
+      state_a = described_class.new(project, user, name: 'my-state').create_or_find!
+      state_b = described_class.new(project, user, name: 'my-state').create_or_find!
+
+      expect(state_a).to be_persisted
+      expect(state_a.id).to eq state_b.id
+    end
+  end
+
+  context 'when state locking is not being used' do
+    subject { described_class.new(project, user, name: 'my-state') }
+
+    describe '#handle_with_lock' do
+      it 'allows to modify a state using database locking' do
+        state = subject.handle_with_lock do |state|
+          state.name = 'updated-name'
+        end
+
+        expect(state.name).to eq 'updated-name'
+      end
+
+      it 'returns the state object itself' do
+        state = subject.create_or_find!
+
+        expect(state.name).to eq 'my-state'
+      end
+    end
+
+    describe '#lock!' do
+      it 'raises an error' do
+        expect { subject.lock! }.to raise_error(ArgumentError)
+      end
+    end
+  end
+
+  context 'when using locking' do
+    describe '#handle_with_lock' do
+      it 'handles a locked state using exclusive read lock' do
+        handler = described_class
+          .new(project, user, name: 'new-state', lock_id: 'abc-abc')
+
+        handler.lock!
+
+        state = handler.handle_with_lock do |state|
+          state.name = 'new-name'
+        end
+
+        expect(state.name).to eq 'new-name'
+      end
+    end
+
+    it 'raises exception if lock has not been acquired before' do
+      handler = described_class
+        .new(project, user, name: 'new-state', lock_id: 'abc-abc')
+
+      expect { handler.handle_with_lock }
+        .to raise_error(described_class::StateLockedError)
+    end
+
+    describe '#lock!' do
+      it 'allows to lock state if it does not exist yet' do
+        handler = described_class.new(project, user, name: 'new-state', lock_id: 'abc-abc')
+
+        state = handler.lock!
+
+        expect(state).to be_persisted
+        expect(state.name).to eq 'new-state'
+      end
+
+      it 'allows to lock state if it exists and is not locked' do
+        state = described_class.new(project, user, name: 'new-state').create_or_find!
+        handler = described_class.new(project, user, name: 'new-state', lock_id: 'abc-abc')
+
+        handler.lock!
+
+        expect(state.reload.lock_xid).to eq 'abc-abc'
+        expect(state).to be_locked
+      end
+
+      it 'raises an exception when trying to unlocked state locked by someone else' do
+        described_class.new(project, user, name: 'new-state', lock_id: 'abc-abc').lock!
+
+        handler = described_class.new(project, user, name: 'new-state', lock_id: '12a-23f')
+
+        expect { handler.lock! }.to raise_error(described_class::StateLockedError)
+      end
+    end
+  end
+end