Rails 6.0 will require Ruby >= 2.5.0 - see rails/rails#34754.

See here: rails/rails@a2be6ce

See: #2071 (comment)

In Rails 6 the `ActionView::Template#formats` method has been deprecated
[1] and replaced with `ActionView::Template#format` method.

I have attempted to retain support for Rails <= 5.2.

[1] https://www.github.com/rails/rails/commit/ca5e23ed4d8

We had some warnings:
> DEPRECATION WARNING: ActionView::Template#initialize requires a locals parameter (called from new at /Users/benoit.tigeot/code/rspec-dev/repos/rspec-rails/lib/rspec/rails/view_rendering.rb:54)

This was introduced by rails/rails#35411

Related 6061628

now blocked on rails/rails#36030

Fix:
Error: The `Layout/FirstParameterIndentation` cop has been renamed to `Layout/IndentFirstArgument`.
(obsolete configuration found in .rubocop_rspec_base.yml, please update it)
The `Layout/IndentArray` cop has been renamed to `Layout/IndentFirstArrayElement`.
(obsolete configuration found in .rubocop_rspec_base.yml, please update it)

this provide parity with have_enqueued_job with partial arguments
which would be useful especially in negated case where
we want to make sure that absolutely no emails are enqueued

* Add ActionMailbox spec helpers and test type

Adds the following helpers to example groups with `:type => :mailbox`

* process(mail_or_attributes) - send mail directly to the mailbox under test for
  `process`ing.
* receive_inbound_email(mail_or_attributes) - matcher for asserting whether incoming
  email would route to the mailbox under test.
* have_been_delivered - matcher for asserting whether an incoming email object was delivered.
* have_bounced - matcher for asserting whether an incoming email object has bounced.
* have_failed - matcher for asserting whether an incoming email object has failed.

Also adds an ActionMailbox test generator

* Add style changes from code review

- fix warnings for wrong namespaces
- fix safe navigation offense
- turn off frozen string literal cop

this provide parity with have_enqueued_job with partial arguments
which would be useful especially in negated case where
we want to make sure that absolutely no emails are enqueued

The previous documentation was old and was not clear enough to help
developers to understand properly how to test cookies inside a
controller test. Since then it is much easier to test cookies if you
stick to `cookies` and don't use `response.cookies`.

You can use response.cookies when you don't change cookies inside your
test.

```
def show
  cookies["user_name"] = nil
  head 200
end

RSpec.describe SignOutsController, type: :request do
  describe 'GET /signout' do
    it "clear cookie value" do
      get "/sign_out"

      expect(response.cookies["user_name"]).to eq(nil)
    end
  end
end
```

Use `cookies` to set and expect when you set cookies inside your test

```
def show
  cookies.delete("user_name")
  head 200
end

RSpec.describe SignOutsController, type: :request do
  describe 'GET /signout' do
    it "clear cookie value" do
      cookies["user_name"] = "Sam"

      get "/sign_out"

      expect(cookies["user_name"]).to eq("")
    end
  end
end
```

This is the prefered way and this is way it is documented like that.

Related:
- #1993

- parameterized mailer when RAILS_VERSION >= 5.1
- unified mailer job when RAILS_VERSION >= 6.0

action-cable-testing migration, pt.1

add support for recognizing mailer many jobs:

Addressing Jon code-review on 4-0-dev

use jbuilder from rubygems

See: rails/rails#36034

This feature test is filtered on @rails_post_5

…nerator

Create controller generator for routing specs

Prevent uninstalling bundler on newer rails

Blowaway before hooks as well as after hooks to preserve order

[skip ci]

Prevent webdrivers from using `&.` method on unsupported ruby.

RVM doesn't provide old Ruby binaries for newer Ubuntu distributions.
Until it's fixed, we need to use old Ubuntu distributions in CI.