title: Why do I need to migrate the test database in Rails?
body: <p>After creating a new migration file, running the migration, then running my tests I receive:</p>
  
  <pre><code>Failure/Error: ActiveRecord::Migration.maintain_test_schema!
  
  ActiveRecord::PendingMigrationError:
  
    Migrations are pending. To resolve this issue, run:
  
            bin/rails db:migrate RAILS_ENV=test
  </code></pre>
  
  <p>Isn't the following snippet in the <code>rails_helper.rb</code> supposed to apply the migrations to the test database for me?</p>
  
  <pre><code># Checks for pending migration and applies them before tests are run.
  # If you are not using ActiveRecord, you can remove this line.
  ActiveRecord::Migration.maintain_test_schema!
  </code></pre>
  
  <p><strong>Update</strong></p>
  
  <p>Here is my <code>config/environments/test.rb</code> as requested:</p>
  
  <pre><code>Rails.application.configure do
    # Settings specified here will take precedence over those in config/application.rb.
  
    # The test environment is used exclusively to run your application's
    # test suite. You never need to work with it otherwise. Remember that
    # your test database is "scratch space" for the test suite and is wiped
    # and recreated between test runs. Don't rely on the data there!
    config.cache_classes = true
  
    # Do not eager load code on boot. This avoids loading your whole application
    # just for the purpose of running a single test. If you are using a tool that
    # preloads Rails for running tests, you may have to set it to true.
    config.eager_load = false
  
    # Configure public file server for tests with Cache-Control for performance.
    config.public_file_server.enabled = true
    config.public_file_server.headers = {
      'Cache-Control' =&gt; 'public, max-age=3600'
    }
  
    # Show full error reports and disable caching.
    config.consider_all_requests_local       = true
    config.action_controller.perform_caching = false
  
    # Raise exceptions instead of rendering exception templates.
    config.action_dispatch.show_exceptions = false
  
    # Disable request forgery protection in test environment.
    config.action_controller.allow_forgery_protection = false
    config.action_mailer.perform_caching = false
  
    # Tell Action Mailer not to deliver emails to the real world.
    # The :test delivery method accumulates sent emails in the
    # ActionMailer::Base.deliveries array.
    config.action_mailer.delivery_method = :test
  
    # Print deprecation notices to the stderr.
    config.active_support.deprecation = :stderr
  
    # Raises error for missing translations
    # config.action_view.raise_on_missing_translations = true
  end
  </code></pre>