feat: add GlobalConfigService to support env vars migration (#3288)

spec/lib/global_config_service_spec.rb

@@ -0,0 +1,44 @@
+require 'rails_helper'
+
+describe GlobalConfigService do
+  subject(:trigger) { described_class }
+
+  describe 'execute' do
+    context 'when called with default options' do
+      before do
+        # to clear redis cache
+        GlobalConfig.clear_cache
+      end
+
+      it 'set default value if not found on db nor env var' do
+        value = GlobalConfig.get('ENABLE_ACCOUNT_SIGNUP')
+        expect(value['ENABLE_ACCOUNT_SIGNUP']).to eq nil
+
+        described_class.load('ENABLE_ACCOUNT_SIGNUP', 'true')
+
+        value = GlobalConfig.get('ENABLE_ACCOUNT_SIGNUP')
+        expect(value['ENABLE_ACCOUNT_SIGNUP']).to eq 'true'
+        expect(InstallationConfig.find_by(name: 'ENABLE_ACCOUNT_SIGNUP')&.value).to eq 'true'
+      end
+
+      it 'get value from env variable if not found on DB' do
+        with_modified_env ENABLE_ACCOUNT_SIGNUP: 'false' do
+          expect(InstallationConfig.find_by(name: 'ENABLE_ACCOUNT_SIGNUP')&.value).to eq nil
+          described_class.load('ENABLE_ACCOUNT_SIGNUP', 'true')
+          value = GlobalConfig.get('ENABLE_ACCOUNT_SIGNUP')
+          expect(value['ENABLE_ACCOUNT_SIGNUP']).to eq 'false'
+        end
+      end
+
+      it 'get value from DB if found' do
+        # Set a value in db first and make sure this value
+        # is not respected even when load() method is called with
+        # another value.
+        InstallationConfig.where(name: 'ENABLE_ACCOUNT_SIGNUP').first_or_create(value: 'true')
+        described_class.load('ENABLE_ACCOUNT_SIGNUP', 'false')
+        value = GlobalConfig.get('ENABLE_ACCOUNT_SIGNUP')
+        expect(value['ENABLE_ACCOUNT_SIGNUP']).to eq 'true'
+      end
+    end
+  end
+end