feat: add rails crendentails support

Author: noxasch

README.md

@@ -274,6 +274,7 @@ After installing `Config` in Rails, you will find automatically generated file t
 * `evaluate_erb_in_yaml` - evaluate ERB in YAML config files. Set to false if the config file contains ERB that should not be evaluated at load time. Default: `true`
 * `file_name` - name of the file to store general keys accessible in all environments. Default: `'settings'` - located at `config/settings.yml`
 * `dir_name` - name of the directory to store environment-specific files. Default: `'settings'` - located at `config/settings/`
+* `use_rails_credentials` - evaluate Rails credentials if loaded with `RAILS_MASTER_KEY` or `config/master.key`
 
 ### Merge customization
 

lib/config.rb

@@ -29,6 +29,7 @@ module Config
     validation_contract: nil,
     evaluate_erb_in_yaml: true,
     environment: nil
+    use_rails_credentials: false
   )
 
   def self.setup
@@ -48,6 +49,10 @@ def self.load_files(*sources)
 
     config.add_source!(Sources::EnvSource.new(ENV)) if Config.use_env
 
+    if defined?(::Rails::Railtie) && Config.use_rails_credentials
+      config.add_source!(Rails.application.credentials.to_h.deep_stringify_keys) 
+    end
+
     config.load!
     config
   end

spec/config_spec.rb

@@ -480,5 +480,36 @@
       end
 
     end
+
+    context 'rails crendentials' do
+      let(:config) do
+        Config.use_rails_credentials = true
+      end
+
+      if defined?(::Rails)
+        it 'shoud have secret_key_base loaded' do
+          expect(Settings.to_h.keys.include?('secret_key_base')).to eq(true)
+        end
+
+        
+        context 'use_rails_credentials is false' do
+          let(:config) do
+            Config.use_rails_credentials = false
+          end
+
+          it 'shoud have secret_key_base loaded' do
+            expect(Settings.to_h.keys.include?('secret_key_base')).to eq(false)
+          end
+        end
+      end
+      
+      unless defined?(::Rails)
+        context 'when not using rails' do
+          it 'shoud have secret_key_base loaded' do
+            expect(Settings.to_h.keys.include?('secret_key_base')).to eq(false)
+          end
+        end
+      end
+    end
   end
 end