Chore: Add migration for feature flags (#1024)

Co-authored-by: Pranav Raj Sreepuram <pranavrajs@gmail.com>

config/app.yml

@@ -1,5 +1,5 @@
 shared: &shared
-  version: '1.5.3'
+  version: '1.6.1'
 
 development:
   <<: *shared

db/migrate/20200709145000_remove_multiple_feature_flags.rb

@@ -0,0 +1,21 @@
+class RemoveMultipleFeatureFlags < ActiveRecord::Migration[6.0]
+  def change
+    current_config = InstallationConfig.where(name: 'ACCOUNT_LEVEL_FEATURE_DEFAULTS').last
+    InstallationConfig.where(name: 'ACCOUNT_LEVEL_FEATURE_DEFAULTS').where.not(id: current_config.id).destroy_all
+    ConfigLoader.new.process
+    update_existing_accounts
+  end
+
+  def update_existing_accounts
+    feature_config = InstallationConfig.find_by(name: 'ACCOUNT_LEVEL_FEATURE_DEFAULTS')
+    facebook_config = feature_config.value.find { |value| value['name'] == 'channel_facebook' }
+    twitter_config = feature_config.value.find { |value| value['name'] == 'channel_twitter' }
+    Account.find_in_batches do |account_batch|
+      account_batch.each do |account|
+        account.enable_features(['channel_facebook']) if facebook_config['enabled']
+        account.enable_features(['channel_twitter']) if twitter_config['enabled']
+        account.save!
+      end
+    end
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2020_07_04_173104) do
+ActiveRecord::Schema.define(version: 2020_07_09_145000) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "pg_stat_statements"

lib/config_loader.rb

@@ -74,11 +74,11 @@ class ConfigLoader
   def compare_and_save_feature(config)
     features = if @reconcile_only_new
                  # leave the existing feature flag values as it is and add new feature flags with default values
-                 (account_features + config.value).uniq { |h| h['name'] }
+                 (config.value + account_features).uniq { |h| h['name'] }
                else
                  # update the existing feature flag values with default values and add new feature flags with default values
-                 (config.value + account_features).uniq { |h| h['name'] }
+                 (account_features + config.value).uniq { |h| h['name'] }
                end
-    save_as_new_config({ name: 'ACCOUNT_LEVEL_FEATURE_DEFAULTS', value: features })
+    config.update({ name: 'ACCOUNT_LEVEL_FEATURE_DEFAULTS', value: features })
   end
 end