fix: check database and table's existence before getting the metadata. (

#8)

* chore: no need to rescue

* chore: add a bit comments

* chore: fix rubocop issue

lib/adapters/wallaby/active_record/model_decorator.rb

@@ -40,14 +40,14 @@ class ModelDecorator < ::Wallaby::ModelDecorator
       # @return [ActiveSupport::HashWithIndifferentAccess] metadata
       def fields
         @fields ||= ::ActiveSupport::HashWithIndifferentAccess.new.tap do |hash|
-          # NOTE: There is a chance that people create ActiveRecord class
-          # before they do the migration, so initialising the fields will raise
-          # all kinds of error. Therefore, we need to check the table existence
-          if @model_class.table_exists?
-            hash.merge! general_fields
-            hash.merge! association_fields
-            hash.except!(*foreign_keys_from_associations)
-          end
+          # NOTE: Need to check database and table's existence
+          # before pulling out the metadata from model.
+          # So that the database and migration related task can be executed.
+          next unless ::ActiveRecord::Base.connected? && @model_class.table_exists?
+
+          hash.merge! general_fields
+          hash.merge! association_fields
+          hash.except!(*foreign_keys_from_associations)
         end.freeze
       end
 

spec/features/database_active_check_spec.rb

@@ -0,0 +1,23 @@
+require 'rails_helper'
+
+describe 'Database active check' do
+  let(:model_class) { Blog }
+  let(:model_decorator) { Wallaby::ActiveRecord::ModelDecorator.new model_class }
+
+  context 'when database does not exist' do
+    it 'returns empty hash' do
+      expect(::ActiveRecord::Base).to receive(:connected?).and_return(false)
+      expect(model_decorator.fields).to eq({})
+    end
+  end
+
+  context 'when table does not exist' do
+    let(:model_class) { stub_const 'NotFoundTable', Class.new(ActiveRecord::Base) }
+
+    it 'returns empty hash' do
+      expect(::ActiveRecord::Base).to be_connected
+      expect(model_class).not_to be_table_exists
+      expect(model_decorator.fields).to eq({})
+    end
+  end
+end