- These initializers are new defaults for Rails 5 and newly generated
  apps do not need to change them.
- Fixes #25181

Follow up to e45f388e.

When changing the generated integration tests to assert redirects with
an absolute path this redirection check in `assert_redirected_to` against
the absolute response location would now pass:
https://github.com/rails/rails/blob/af245aaf3a1c447752a1b5895adddc66e5f73c00/actionpack/lib/action_dispatch/testing/assertions/response.rb#L55

Thus we'd break early instead of hitting `assert_operator` and have
2 fewer assertions per `assert_redirected_to` as `assert_operator`
is composed of 2 assertions internally:
https://github.com/seattlerb/minitest/blob/4e146b1515b19a5c474e39c174b037510f6dbc6e/lib/minitest/assertions.rb#L254-L258

Deduct 2 assertions for 2 redirects taking the expected count down by 4
in total for the two failing tests.

The first comment does not explain anything that the code doesnt and the second is now irrelevant with the dedicated API mode

- Fixes #25180

Introduced in d6f2000a and was only used by Action Cable. Now handled by Action Cable’s assets:compile task.

Adding '$' to emulate shell syntax

[ci skip]

When RAILS_MAX_THREADS is set, the postgresql adapter uses it as the
connection pool size, so that there are always enough connections
available to serve Action Cable requests.

The same logic applies when using any other adapter.

[ci skip]

Sorry, I missed a few places in my last PR. This should be the last of
'em 😬

Cable: Generate .js or .coffee files while generating channel as per the javascript engine of the application

- Now we will detect what javascript engine user is using and based on
  that we will generate either `.js` or `.coffee` version of the channel
  file.
- This also needs a change in coffee-rails to override the `js_template`
  method. Related PR https://github.com/rails/coffee-rails/pull/72.
- Currently coffee-rails gem sets
  `config.app_generators.javascript_engine` to `:coffee` and using this
  information we override the `js_template` to set the extension as
  `.coffee` in coffee-rails gem.
- Using this approach, we can keep the `channel.js` and `channel.coffee`
  files in the Rails repository itself.
- Additionally the `js_template` method can act as public interface for
  coffee-rails gem to hook into and change the extension to `.coffee`
  without maintaining the actual asset files.

[Prathamesh Sonpatki, Matthew Draper]

Conventionally envs are ordered development -> test -> production.

It is related with https://github.com/rack/rack/commit/7b66d2cdb80a4d6b44fa8c61d92e25fbbda1f152

[ci skip]

In order to prevent `OptionParser::ParseError` when specify the rake options to
`routes` task.

If run the test over the `rake` command, because of the test patterns is passed
via `rake_run` method, do not need to be obtained from the argv.

This probably fixes #24372.

`railtie` is already a string!

- Followup of https://github.com/rails/rails/pull/24709.

In Ruby 2.4 the `to_time` method for both `DateTime` and `Time` will
preserve the timezone of the receiver when converting to an instance
of `Time`. Since Rails 5.0 will support Ruby 2.2, 2.3 and later we
need to introduce a compatibility layer so that apps that upgrade do
not break. New apps will have a config initializer file that defaults
to match the new Ruby 2.4 behavior going forward.

For information about the changes to Ruby see:
https://bugs.ruby-lang.org/issues/12189
https://bugs.ruby-lang.org/issues/12271

Fixes #24617.

`bundler` provides wrapper file to add rask tasks.
https://github.com/bundler/bundler/blob/master/lib/bundler/gem_tasks.rb

Instead of directly call method, by which require this file,
it can be used without updating of Rakefile if task has been added.

Railties' `config` method instatiates a Rails::Railtie::Configuration
object. Rails::Configuration is not used in this file.

The patch does not replace the file being required with the one for
Rails::Railtie::Configuration because that one is autoloaded. See the
spot where this patch changes double quotes with single quotes.

Rails::Railtie::Configuration does depend on Rails::Configuration, and
it requires it accordingly.

`cable.js` is required for other Channels.

- Before this, while generating a channel, we were not creating
  `cable.js` if it does not already exist.
- We have similar code for application mailer here -
  https://github.com/rails/rails/commit/0b3ae023d27197417541932632055cd6be4810c4.
- Based on the comment -
  https://github.com/rails/rails/issues/24418#issuecomment-205421995.

The pass touches a few minor things.

One important aspect is that the wording treats "railtie" as a
regular noun. This is so because Railtie is a constant and
generally the text refers to "classes that act as railties",
which is different.

Railties are so fundamental in Rails that deserve a noun,
like engine, class, array, application, etc. They have a
meaning per se, beyond constants.

Also, make clear an extension's railtie does not need to
be called "Railtie" or have "Railtie" in their class name.