Custom rake task for DB: Table not found - mysql

Question

I have a custom rake task, that creates a development DB with data for various situation. The core looks like this:
namespace :db do
task setup_seed: :environment do
Rake::Task['db:drop'].invoke
Rake::Task['db:create'].invoke
Rake::Task['db:schema:load'].invoke
Rake::Task['db:migrate'].invoke
Rake::Task['db:test:prepare'].invoke
Rake::Task['db:seed'].invoke
end
end
Everything runs fine, until db:seed is invoked, because it throws an error that tables does not exist. This is my seed.rb:
puts Rails.env
# => development
puts Article.count
# rake aborted!
# Mysql2::Error: Table 'app_test.articles' doesn't exist: SHOW FULL FIELDS FROM `articles`
# /usr/src/app/db/seeds.rb:2:in `<top (required)>'
# /usr/src/app/Rakefile:16:in `block (2 levels) in <top (required)>'
# Tasks: TOP => db:seed
I noticed two strange things here:
First of all it doesn't find the table articles (or any table). When I halt at the beginning of my seed file and look into the DB (development), the tables are present, but the test db is empty
I've printed the Rails.env and it returns development. However the failure message states that it tries to load the DB app_test.articles and not app_development.articles.
So I think this two issues are related.

Answer 1

It looks like you are running your rake task in development environment, but db:test:prepare runs in test by default. Try invoking:
RAILS_ENV=test rake db:setup_seed

Answer 2

I found the solution myself. The problem was, that the task Rake::Task['db:test:prepare'].invoke changes the environment to test, so putting that line to the bottom of the script and everything works:
namespace :db do
task setup_seed: :environment do
Rake::Task['db:drop'].invoke
Rake::Task['db:create'].invoke
Rake::Task['db:schema:load'].invoke
Rake::Task['db:migrate'].invoke
Rake::Task['db:seed'].invoke
Rake::Task['db:test:prepare'].invoke # this one should be at the bottom
end
end