Prevent locking a Terraform state if it is already locked

https://gitlab.com/gitlab-org/gitlab/-/merge_requests/43955

app/graphql/mutations/terraform/state/lock.rb

@@ -8,7 +8,12 @@ module Mutations
 
         def resolve(id:)
           state = authorized_find!(id: id)
-          state.update(lock_xid: lock_xid, locked_by_user: current_user, locked_at: Time.current)
+
+          if state.locked?
+            state.errors.add(:base, 'state is already locked')
+          else
+            state.update(lock_xid: lock_xid, locked_by_user: current_user, locked_at: Time.current)
+          end
 
           { errors: errors_on_object(state) }
         end

spec/graphql/mutations/terraform/state/delete_spec.rb

@@ -4,8 +4,8 @@ require 'spec_helper'
 
 RSpec.describe Mutations::Terraform::State::Delete do
   let_it_be(:user) { create(:user) }
+  let_it_be(:state) { create(:terraform_state) }
 
-  let(:state) { create(:terraform_state) }
   let(:mutation) do
     described_class.new(
       object: double,

spec/graphql/mutations/terraform/state/lock_spec.rb

@@ -4,8 +4,8 @@ require 'spec_helper'
 
 RSpec.describe Mutations::Terraform::State::Lock do
   let_it_be(:user) { create(:user) }
+  let_it_be(:state) { create(:terraform_state) }
 
-  let(:state) { create(:terraform_state) }
   let(:mutation) do
     described_class.new(
       object: double,
@@ -42,6 +42,18 @@ RSpec.describe Mutations::Terraform::State::Lock do
         expect(state.lock_xid).to be_present
         expect(state.locked_at).to be_present
       end
+
+      context 'state is already locked' do
+        let(:locked_by_user) { create(:user) }
+        let(:state) { create(:terraform_state, :locked, locked_by_user: locked_by_user) }
+
+        it 'does not modify the existing lock', :aggregate_failures do
+          expect(subject).to eq(errors: ['state is already locked'])
+
+          expect(state.reload).to be_locked
+          expect(state.locked_by_user).to eq(locked_by_user)
+        end
+      end
     end
 
     context 'with invalid params' do

spec/graphql/mutations/terraform/state/unlock_spec.rb

@@ -4,8 +4,8 @@ require 'spec_helper'
 
 RSpec.describe Mutations::Terraform::State::Unlock do
   let_it_be(:user) { create(:user) }
+  let_it_be(:state) { create(:terraform_state, :locked) }
 
-  let(:state) { create(:terraform_state, :locked) }
   let(:mutation) do
     described_class.new(
       object: double,
@@ -38,6 +38,15 @@ RSpec.describe Mutations::Terraform::State::Unlock do
         expect(subject).to eq(errors: [])
         expect(state.reload).not_to be_locked
       end
+
+      context 'state is already unlocked' do
+        let(:state) { create(:terraform_state) }
+
+        it 'does not modify the state' do
+          expect(subject).to eq(errors: [])
+          expect(state.reload).not_to be_locked
+        end
+      end
     end
 
     context 'with invalid params' do

spec/requests/api/graphql/terraform/state/lock_spec.rb

@@ -18,7 +18,7 @@ RSpec.describe 'lock a terraform state' do
 
   include_examples 'a working graphql query'
 
-  it 'unlocks the state' do
+  it 'locks the state' do
     expect(state.reload).to be_locked
     expect(state.locked_by_user).to eq(user)
   end