Add an after_bundle callback in Rails templates

[skanev]

Closes #16292.

The following Rails template (taken from the Rails guides) does not work well with binstubs:

# template.rb
generate(:scaffold, "person name:string")
route "root to: 'people#index'"
rake("db:migrate")

git :init
git add: "."
git commit: %Q{ -m 'Initial commit' }

Since it is executed before Bundler and Spring binstub generation, the generated stubs are not added to version control. Executing the templates later wouldn't work either – that way it won't be able to add gems.

Adding an after_bundle callback seems to solve the issue. That way, the version control commands can be postponed after the binstubs have been generated:

# template.rb
generate(:scaffold, "person name:string")
route "root to: 'people#index'"
rake("db:migrate")

after_bundle do
  git :init
  git add: "."
  git commit: %Q{ -m 'Initial commit' }
end

This pull request implements that callback. The test is a mouthful – I'm open to suggestions for improvements 😄

/cc @senny

[robin850]

Could you avoid using Mocha please ? We are trying to remove it from the test suite. Thanks for the patch so far, it looks great! 👍

[skanev]

I can try, but I'm not sure how. I arrived at this code by following the style of the surrounding tests. I want to check that:

1. `bundle gets run
2. ...then binstubs get generated
3. ...then the after_bundle callbacks get executed

Surely the test cannot invoke bundle, since it will make them (1) nondeterministic and (2) dependant on internet connection. Also, (3) very slow. Calls to the first two need to get stubbed in some way.

If I'm not allowed to use Mocha, I'm not sure how to handle it. I can define singleton methods on generator, but that will surely get messier and harder to understand.

There is also the business of supplying a template. Since a string containing code cannot be passed to generator, there's this path and template.instance_eval business that I borrowed from a test in the same suite. If I'm to remove Mocha, we should also figure out how to do that.

Finally, if the other tests in the suite can benefit from the same approach. Maybe there are a few nice abstractions that can be extracted and all the tests can benefit from them. This feels like another, larger task. I'd love to do it also (in a separate PR possibly), but I'll definitely need some hints on how to do it :)

[senny]

@robin850 given that the surrounding tests use the same pattern I don't think we need to tackle this in the same PR. Basically if one does remove Mocha for one of the tests it should be trivial to remove it for the others. They are all doing mostly the same stuff.

[rafaelfranca]

Yes. No bother with mocha. I'll deal with it.

[robin850]

given that the surrounding tests use the same pattern I don't think we need to tackle this in the same PR

Ah fair point 👍

[itsNikolay]

@skanev does git init happen when generator will be run with --skip-bundle option ?

[skanev]

@itsNikolay Yup, the after_bundle callbacks get executed even if --skip-bundle is passed.

[senny]

@skanev I think the docs should mention that after_bundle runs even if --skip-bundle was passed.

[skanev]

@senny I've added it to the guide.

[skanev]

I've rebased onto master, squashed the two commits into one and added a reference to the fixed issue in the changelog.

[senny]

As this is a breaking change (well not directly but the user needs to modify his templates) we should include it in the release notes and the upgrading guide.

[skanev]

I've added it to the release notes and upgrade guide in c294e91.