Improved RSpec system_init_done helper for DB migrations

Since DB migrations usually always check for system_init_done this is the new default behavior for all examples in a `type: :db_migration` spec. The default state is that Zammad is already initialized. This can be changed by passing `false` as a value to the meta tag `system_init_done`. See `spec/support/db_migration.rb` for more information.

spec/db/migrate/check_for_object_attributes_spec.rb

@@ -2,9 +2,7 @@ require 'rails_helper'
 
 RSpec.describe CheckForObjectAttributes, type: :db_migration do
 
-  it 'performs no action for new systems' do
+  it 'performs no action for new systems', system_init_done: false do
-    system_init_done(false)
-
     migrate do |instance|
       expect(instance).not_to receive(:attributes)
     end
@@ -13,8 +11,6 @@ RSpec.describe CheckForObjectAttributes, type: :db_migration do
   context 'valid [:data_option]' do
 
     it 'does not change converted text attribute' do
-      system_init_done
-
       attribute = create(:object_manager_attribute_text)
 
       expect do
@@ -25,8 +21,6 @@ RSpec.describe CheckForObjectAttributes, type: :db_migration do
     end
 
     it 'does not change select attribute' do
-      system_init_done
-
       attribute = create(:object_manager_attribute_select)
 
       expect do
@@ -37,8 +31,6 @@ RSpec.describe CheckForObjectAttributes, type: :db_migration do
     end
 
     it 'does not change tree_select attribute' do
-      system_init_done
-
       attribute = create(:object_manager_attribute_tree_select)
 
       expect do
@@ -52,8 +44,6 @@ RSpec.describe CheckForObjectAttributes, type: :db_migration do
   context '[:data_option]' do
 
     it 'ensures an empty Hash' do
-      system_init_done
-
       attribute = create(:object_manager_attribute_text, data_option: nil)
       migrate
       attribute.reload
@@ -65,8 +55,6 @@ RSpec.describe CheckForObjectAttributes, type: :db_migration do
   context '[:data_option][:options]' do
 
     it 'ensures an empty Hash' do
-      system_init_done
-
       attribute = create(:object_manager_attribute_text, data_option: {})
       migrate
       attribute.reload
@@ -75,8 +63,6 @@ RSpec.describe CheckForObjectAttributes, type: :db_migration do
     end
 
     it 'converts String to Hash' do
-      system_init_done
-
       wrong = {
         default:  '',
         options:  '',
@@ -96,8 +82,6 @@ RSpec.describe CheckForObjectAttributes, type: :db_migration do
   context '[:data_option][:relation]' do
 
     it 'ensures an empty String' do
-      system_init_done
-
       wrong = {
         default: '',
         options: {},
@@ -112,8 +96,6 @@ RSpec.describe CheckForObjectAttributes, type: :db_migration do
     end
 
     it 'converts Hash to String' do
-      system_init_done
-
       wrong = {
         default:  '',
         options:  {},

spec/support/db_migration.rb

@@ -27,6 +27,27 @@ module DbMigrationHelper
       instance.migrate(direction)
     end
   end
+
+  def self.included(base)
+
+    # Execute in RSpec class context
+    base.class_exec do
+
+      # This method simulates a system that is is already initialized
+      #  aka `Setting.exists?(name: 'system_init_done')`
+      #  It's possible to simulate a not yet initialized system by adding the
+      #  meta tag `system_init_done` to `false` to the needing example:
+      #
+      # @example
+      #  it 'does stuff in an unitialized system', system_init_done: false do
+      #
+      before(:each) do |example|
+        initialized = example.metadata.fetch(:system_init_done, true)
+        system_init_done(initialized)
+      end
+    end
+  end
+
 end
 
 RSpec.configure do |config|

spec/support/system_init_done.rb

@@ -1,5 +1,11 @@
 module SystemInitDoneHelper
   def system_init_done(state = true)
+    # generally allow all calls to Setting.find_by to avoid
+    # RSpec errors where a different Setting is accessed
+    allow(Setting).to receive(:find_by).and_call_original
+
+    # just mock the Setting check for `system_init_done`
+    # and return the given parameter value
     expect(Setting).to receive(:find_by).with(name: 'system_init_done').and_return(state)
   end
 end