Including Wrong in a Rails App

[tjschuck]

I'm having issues including Wrong in a trivial greenfield test application. Though this is more "support" than "issue", I'm guessing whatever the right answer is means the docs need updating.

First, get set up:

$ rails -v
Rails 3.2.3
$ rails new test_app
$ cd test_app/
$ rake db:create
$ rails g scaffold Post title:string body:text
$ rake db:migrate

This will give you a trivial new app with some tests to run:

$ rake test:functionals
Run options: 

# Running tests:

.......

Finished tests in 0.154397s, 45.3377 tests/s, 64.7681 assertions/s.

7 tests, 10 assertions, 0 failures, 0 errors, 0 skips

Okay, great. Now add gem "wrong" to the Gemfile, and bundle install.

Then, add wrong to your test/test_helper.rb file like so: https://gist.github.com/61af0b2b0431e61c1258

Crack open your test/functional/posts_controller_test.rb and add two trivial wrong-style assertions: https://gist.github.com/e75c14cf155e5decdf22

Now run your tests and enjoy your errors:

$ rake test:functionals

# Running tests:

...EE..

Finished tests in 0.160737s, 43.5494 tests/s, 62.2134 assertions/s.

  1) Error:
test_should_get_index(PostsControllerTest):
ArgumentError: wrong number of arguments (0 for 1)
[...]

  2) Error:
test_should_get_new(PostsControllerTest):
ArgumentError: wrong number of arguments (0 for 1)
[...]

7 tests, 10 assertions, 0 failures, 2 errors, 0 skips

The suite is seemingly still trying to use MiniTest's assert, which takes 1 argument.

Thoughts?

[tjschuck]

Additionally, things seem to be working okay in the Rails console:

$ rails c test
Loading test environment (Rails 3.2.3)
> assert { true }
NoMethodError: undefined method `assert' for main:Object
> require 'wrong/adapters/minitest'
=> true
> include Wrong
=> Object
irb(main):004:0> assert { true }
=> nil

[alexch]

Thanks for the detailed report. I'm looking into it now.

[alexch]

Looks like somewhere along the line Rails is including Test::Unit::Assertions into its ActionController::TestCase, even though ultimately it's a MiniTest::Unit::TestCase (with MiniTest::Unit::Assertions to boot). So testunit is overriding wrong's override of minitest's assert. I'll have to dig into the Rails code base to see what's up with that.

[alexch]

Looks like I'm going to have to rework the whole adapter system so that it can differentiate between raw minitest and minitest inside Rails.

In the meantime a workaround is to not do "require 'wrong/adapters/minitest'" and instead just put this in your test_helper.rb:

class ActiveSupport::TestCase
  # ...
  include Wrong
end

The problem with that workaround is that failures will be tallied as errors (since it won't be using the right exception class).