Run Rails Tests without Dropping Test Database

Just wondering if there's a way to run Rails tests without dropping the database. I'm currently only executing unit tests and am using the following rake command to do so开发者_开发技巧: rake test:units.

Thanks for the help in advance!

Just in case this is relevant:

• Rails 3
• Ruby 1.8.7 (MRI)
• Oracle 11g Database
  • activerecord-oracle_enhanced-adapter

In Rails 5 (and possibly earlier versions), just comment-out the following line in spec/rails_helper.rb:

 ActiveRecord::Migration.maintain_test_schema!

This will prevent rake test or rspec from attempting to drop your test DB. You'll need to run migrations manually as well.

For Rails 5.2 this behaviour can be modified setting maintain_test_schema to false in test/test_helper.rb before importing rails/test_help:

ActiveRecord::Base.maintain_test_schema = false
require "rails/test_help"

rails/test_help will check the value of maintain_test_schema to decide if it has to drop/create/migrate the test database or not.

After doing some research, I have found that there isn't a way to do this. The test rake tasks will always drop the database, even when providing the TEST= option as Bohdan suggests.

By using the --trace option, this can be proven. Here is the output:

$ rake test:units TEST=test/unit/post_test.rb --trace
(in /Users/johnnyicon/Development/ror/test-app)
** Invoke test:units (first_time)
** Invoke test:prepare (first_time)
** Invoke db:test:prepare (first_time)
** Invoke db:abort_if_pending_migrations (first_time)
** Invoke environment (first_time)
** Execute environment
** Execute db:abort_if_pending_migrations
** Execute db:test:prepare
** Invoke db:test:load (first_time)
** Invoke db:test:purge (first_time)
** Invoke environment 
** Execute db:test:purge
** Execute db:test:load
** Invoke db:schema:load (first_time)
** Invoke environment 
** Execute db:schema:load
** Execute test:prepare
** Execute test:units

Reading through the Ruby on Rails Guides for Testing, it describes what some of these rake tasks mean. The one to pay particular attention to is the db:test:load task, which you see on the 7th line from the bottom of the output as ** Execute db:test:load. The guides say the following about this task:

Recreate the test database from the current schema.rb

So even if I were to execute the unit tests one by one as Bohdan suggests, the rake task would still recreate the database. Not the answer I was hoping for, but it isn't a problem anymore.

The reason I was asking to begin with was because I did not have access to another database to use for testing, so I was using my development database for testing as well. But since then, I've been able to get another database dedicated for testing.

Thanks anyway Bohdan! I appreciate the help!

This is a rather old post that does the monkey patching of overriding purge/load tasks: http://www.pervasivecode.com/blog/2007/09/22/making-rails-raketest-not-drop-your-pgsql-database/

For those looking for a way to skip Rails' default behavior, try adding this to your Rakefile:

Rake::Task["db:test:prepare"].clear
Rake::Task["db:test:load"].clear
Rake::Task["db:test:purge"].clear

Could you not write a custom Rake task that monkey patched the Rake db:test:load task to do nothing?