How to run a single test from a rails test suite?

Question

How can I run a single test from a rails test suite?

rake test ANYTHING seems to not help.

Answer 1

The best way is to look directly into the guides: http://guides.rubyonrails.org/contributing_to_ruby_on_rails.html#running-tests

cd actionmailer
bundle exec ruby -w -Itest test/mail_layout_test.rb -n test_explicit_class_layout

Answer 2

NOTE: This doesn't run the test via rake. So any code you have in Rakefile will NOT get executed.

To run a single test, use the following command from your rails project's main directory:

ruby -I test test/unit/my_model_test.rb -n test_name

This runs a single test named "name", defined in the MyModelTest class in the specified file. The test_name is formed by taking the test name, prepending it with the word "test", then separating the words with underscores. For example:

class MyModelTest < ActiveSupport::TestCase

  test "valid with good attributes" do
    # do whatever you do
  end

  test "invalid with bad attributes" do
    # do whatever you do
  end
end

You can run both tests via:

ruby -I test test/unit/my_model_test.rb

and just the second test via

ruby -I test test/unit/my_model_test.rb -n test_invalid_with_bad_attributes

Answer 3

For rails 5:

rails test test/models/my_model.rb

Answer 4

If you want to run a single test, you can just run them as a regular Ruby script

ruby actionmailer/test/mail_layout_test.rb

You can also run a whole suite (eg. ActiveRecord or ActionMailer) by cd-ing into the directory and running rake test inside there.

Answer 5

To run a single test in the actual Rails suite:

bundle exec ruby -I"railties/test" actionpack/test/template/form_options_helper_test.rb

Answer 6

That was a silly midnight question of mine. Rails kindly prints the command it is executing upon rake test. The rest is a cut and paste exercise.

~/projects/rails/actionpack (my2.3.4)$ ruby -I"lib:test" "/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake/rake_test_loader.rb" "test/controller/base_test.rb"