chore: Fix db:prepare error in deployments (#1668)

Fixes #1667

Procfile

@@ -1,3 +1,3 @@
-release: bundle exec rails db:prepare
+release: bundle exec rails db:chatwoot_prepare
 web: bin/rails server -p $PORT -e $RAILS_ENV
 worker: bundle exec sidekiq -C config/sidekiq.yml

app.json

@@ -12,9 +12,6 @@
     "vue"
   ],
   "success_url": "/",
-  "scripts": {
-    "postdeploy": "bundle exec rake db:seed"
-  },
   "env": {
     "SECRET_TOKEN": {
       "description": "A secret key for verifying the integrity of signed cookies.",

lib/tasks/db_enhancements.rake

@@ -5,3 +5,28 @@ Rake::Task['db:migrate'].enhance do
     ConfigLoader.new.process
   end
 end
+
+# we are creating a custom database prepare task
+# the default rake db:prepare task isn't ideal for environments like heroku
+# In heroku the database is already created before the first run of db:prepare
+# In this case rake db:prepare tries to run db:migrate from all the way back from the beginning
+# Since the assumption is migrations are only run after schema load from a point x, this could lead to things breaking.
+# ref: https://github.com/rails/rails/blob/main/activerecord/lib/active_record/railties/databases.rake#L356
+db_namespace = namespace :db do
+  desc 'Runs setup if database does not exist, or runs migrations if it does'
+  task chatwoot_prepare: :load_config do
+    ActiveRecord::Base.configurations.configs_for(env_name: Rails.env).each do |db_config|
+      ActiveRecord::Base.establish_connection(db_config.config)
+      # handling case where database was created by the provider, with out running db:setup
+      if ActiveRecord::Base.connection.tables.count.zero?
+        db_namespace['load_config'].invoke if ActiveRecord::Base.schema_format == :ruby
+        ActiveRecord::Tasks::DatabaseTasks.load_schema_current(:ruby, ENV['SCHEMA'])
+        db_namespace['seed'].invoke
+      end
+
+      db_namespace['migrate'].invoke
+    rescue ActiveRecord::NoDatabaseError
+      db_namespace['setup'].invoke
+    end
+  end
+end