Include module in all MiniTest tests like in RSpec - ruby-on-rails

Question

In RSpec I could create helper modules in /spec/support/...
module MyHelpers
def help1
puts "hi"
end
end
and include it in every spec like this:
RSpec.configure do |config|
config.include(MyHelpers)
end
and use it in my tests like this:
describe User do
it "does something" do
help1
end
end
How can I include a module into all MiniTest tests without repeating myself in every test?

Answer 1

From the Minitest README:
=== How to share code across test classes?
Use a module. That's exactly what they're for:
module UsefulStuff
def useful_method
# ...
end
end
describe Blah do
include UsefulStuff
def test_whatever
# useful_method available here
end
end
Just define the module in a file and use require to pull it in. For example, if 'UsefulStuff' is defined in test/support/useful_stuff.rb, you might have require 'support/useful_stuff' in either your individual test file.
UPDATE:
To clarify, in your existing test/test_helper.rb file or in a new test/test_helper.rb file you create, include the following:
Dir[Rails.root.join("test/support/**/*.rb")].each { |f| require f }
which will require all files in the test/support subdirectory.
Then, in each of your individual test files just add
require 'test_helper'
This is exactly analogous to RSpec, where you have a require 'spec_helper' line at the top of each spec file.

Answer 2

minitest does not provide a way to include or extend a module into every test class in the same way RSpec does.
Your best bet is going to be to re-open the test case class (differs, depending on the minitest version you're using) and include whatever modules you want there. You probably want to do this in either your test_helper or in a dedicated file that lets everyone else know you're monkey-patching minitest. Here are some examples:
For minitest ~> 4 (what you get with the Ruby Standard Library)
module MiniTest
class Unit
class TestCase
include MyHelpers
end
end
end
For minitest 5+
module Minitest
class Test
include MyHelperz
end
end
You can then use the included methods in your test:
class MyTest < Minitest::Test # or MiniTest::Unit::TestCase
def test_something
help1
# ...snip...
end
end
Hope this answers your question!

Answer 3

One thing I will do is create my own Test class inheriting from Minitest::Test. This allows me to do any sort of configuration on my base test class and keeping it isolated to my own project1.
# test_helper.rb
include 'helpers/my_useful_module'
module MyGem
class Test < Minitest::Test
include MyUsefulModule
end
end
# my_test.rb
include 'test_helper'
module MyGem
MyTest < Test
end
end
1 This is most likely unneeded, but I like keeping all my gem code isolated.