set engine's route in the functional test is generated in the engine

[y-yagi]

Currently, functional test is generated in the engine does not work properly.

$ ./bin/rails g controller Foo index
      create  app/controllers/blorgh/foo_controller.rb
       route  get 'foo/index'
      invoke  erb
      create    app/views/blorgh/foo
      create    app/views/blorgh/foo/index.html.erb
      invoke  test_unit
      create    test/controllers/blorgh/foo_controller_test.rb
      invoke  helper
      create    app/helpers/blorgh/foo_helper.rb
      invoke    test_unit
      invoke  assets
      invoke    js
      create      app/assets/javascripts/blorgh/foo.js
      invoke    css
      create      app/assets/stylesheets/blorgh/foo.css 

$ bundle exec rake
# Running:

E.

Finished in 0.055383s, 36.1122 runs/s, 18.0561 assertions/s.

  1) Error:
Blorgh::FooControllerTest#test_should_get_index:
ActionController::UrlGenerationError: No route matches {:action=>"index", :controller=>"blorgh/foo"}
    /home/yaginuma/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/actionpack-4.2.1/lib/action_dispatch/journey/formatter.rb:46:in `generate'
    /home/yaginuma/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/actionpack-4.2.1/lib/action_dispatch/routing/route_set.rb:727:in `generate'
    /home/yaginuma/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/actionpack-4.2.1/lib/action_dispatch/routing/route_set.rb:758:in `generate'
    /home/yaginuma/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/actionpack-4.2.1/lib/action_dispatch/routing/route_set.rb:753:in `generate_extras'
    /home/yaginuma/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/actionpack-4.2.1/lib/action_dispatch/routing/route_set.rb:748:in `extra_keys'
    /home/yaginuma/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/actionpack-4.2.1/lib/action_controller/test_case.rb:208:in `assign_parameters'
    /home/yaginuma/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/actionpack-4.2.1/lib/action_controller/test_case.rb:619:in `process'
    /home/yaginuma/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/actionpack-4.2.1/lib/action_controller/test_case.rb:65:in `process'
    /home/yaginuma/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/actionpack-4.2.1/lib/action_controller/test_case.rb:508:in `get'
    /home/yaginuma/program/rails/rails_4-2-1_sample/blorgh/test/controllers/blorgh/foo_controller_test.rb:6:in `block in <class:FooControllerTest>'

2 runs, 1 assertions, 0 failures, 1 errors, 0 skips
rake aborted!
Command failed with status (1): [ruby -I"lib:lib:test"  "/home/yaginuma/.rbenv/versions/2.2.2/lib/ruby/2.2.0/rake/rake_test_loader.rb" "test/**/*_test.rb" ]

In order to work properly, need to set the @routes instance variable to the engine's route.

Therefore, I think good to have engine's route in the generated functional test is set.

[senny]

@y-yagi this seems like a good idea. I'm wondering why we didn't notice that those tests are not working. I vaguely remember that we have some tests in railties that run generated test files. Could you explore to write such a test?

[y-yagi]

@senny Thank you for the review! I added test to run generated test files.
At that time, fixture name problem occurs, I was fixed together.

[senny]

do we still need this test? Looks like a duplication of the one following right after.

[y-yagi]

@senny Thank you for the review!
Move the test to the appropriate place, and has been deleted duplicate test.

[senny]

@y-yagi fantastic. Thank you 💛

I added an entry to the changelog in the merge-commit.

[y-yagi]

@senny Thanks!