Database Cleaner not working in minitest rails

My Minitest controller tests are working fine if I run them alone using rake minitest:controllers but when I run rake minitest:all then I get validation failed error. It is because email is already used in model tests. I used DatabaseCleaner to clean the database but unable to clean database.

My code for database cleaner:

require "database_cleaner"
DatabaseCleaner.strategy = :transaction

class MiniTest::Rails::ActionController::TestCase
    include Devise::TestHelpers

    def setup
      DatabaseCleaner.start
    end

    def teardown
      DatabaseCleaner.clean
    end

Short answer:

gem install "minitest-around"

Long answer:

before/after or setup/teardown in minitest are NOT hooks as in rspec, therefore you can't have multiple before/after or setup/teardown in minitest, since what they do is just redefining the method.

To solve this issue, you can use minitest-around, which adds support for multiple before/after or setup/teardown and around, simply add the gem to your test group:

# put in your Gemfile
gem 'minitest-around', group: :test

For setting up the database_cleaner, you can have it as you want, following is an example of the setup:

# tests/support/database_cleaner.rb
DatabaseCleaner.strategy = :transaction
DatabaseCleaner.clean_with(:truncation)

class Minitest::Rails::ActionController::TestCase
  def setup
    DatabaseCleaner.start
  end

  def teardown
    DatabaseCleaner.clean
  end
end

And in your test files:

# tests/your/test/file_test.rb
require 'support/database_cleaner'

# assertions here ...

That's it, see the Github for detailed info.