Fix deployment merge request link creation

This commit fixes the deployment and merge request link
creation that it ignores production grade environments if it's
foldered.

Changelog: fixed

app/models/environment.rb

@@ -425,6 +425,14 @@ class Environment < ApplicationRecord
     clear_reactive_cache!
   end
 
+  def should_link_to_merge_requests?
+    unfoldered? || production? || staging?
+  end
+
+  def unfoldered?
+    environment_type.nil?
+  end
+
   private
 
   def rollout_status_available?

app/services/deployments/link_merge_requests_service.rb

@@ -16,7 +16,7 @@ module Deployments
       # Review apps have the environment type set (e.g. to `review`, though the
       # exact value may differ). We don't want to link merge requests to review
       # app deployments, as this is not useful.
-      return if deployment.environment.environment_type
+      return unless deployment.environment.should_link_to_merge_requests?
 
       # This service is triggered by a Sidekiq worker, which only runs when a
       # deployment is successful. We add an extra check here in case we ever

spec/models/environment_spec.rb

@@ -1710,4 +1710,36 @@ RSpec.describe Environment, :use_clean_rails_memory_store_caching do
       subject
     end
   end
+
+  describe '#should_link_to_merge_requests?' do
+    subject { environment.should_link_to_merge_requests? }
+
+    context 'when environment is foldered' do
+      context 'when environment is production tier' do
+        let(:environment) { create(:environment, project: project, name: 'production/aws') }
+
+        it { is_expected.to eq(true) }
+      end
+
+      context 'when environment is development tier' do
+        let(:environment) { create(:environment, project: project, name: 'review/feature') }
+
+        it { is_expected.to eq(false) }
+      end
+    end
+
+    context 'when environment is unfoldered' do
+      context 'when environment is production tier' do
+        let(:environment) { create(:environment, project: project, name: 'production') }
+
+        it { is_expected.to eq(true) }
+      end
+
+      context 'when environment is development tier' do
+        let(:environment) { create(:environment, project: project, name: 'development') }
+
+        it { is_expected.to eq(true) }
+      end
+    end
+  end
 end

spec/services/deployments/link_merge_requests_service_spec.rb

@@ -32,6 +32,19 @@ RSpec.describe Deployments::LinkMergeRequestsService do
       end
     end
 
+    context 'when the deployment is for one of the production environments' do
+      it 'links merge requests' do
+        environment =
+          create(:environment, environment_type: 'production', name: 'production/gcp')
+
+        deploy = create(:deployment, :success, environment: environment)
+
+        expect(deploy).to receive(:link_merge_requests).once
+
+        described_class.new(deploy).execute
+      end
+    end
+
     context 'when the deployment failed' do
       it 'does nothing' do
         environment = create(:environment, name: 'foo')