Not all requirements can be expressed in terms of polymorphic url
options so add a `route_for` method that allows calling another
direct route (or regular named route) which a set of arguments, e.g:

    resources :buckets

    direct :recordable do |recording|
      route_for(:bucket, recording.bucket)
    end

    direct :threadable do |threadable|
      route_for(:recordable, threadable.parent)
    end

This maintains the context of the original caller, e.g.

    threadable_path(threadable) # => /buckets/1
    threadable_url(threadable)  # => http://example.com/buckets/1

Pass options to `driven_by`

Remove ability update locking_column value

Use it to specify that an association should be initialized with a
particular record before validation. For example:

    # Before
    belongs_to :account
    before_validation -> { self.account ||= Current.account }

    # After
    belongs_to :account, default: -> { Current.account }

Capybara was updated in teamcapybara/capybara#1841 to use Minitest style
assertions so that system test output shows x number of assertions, x
numbe of failures, etc.

Before:

```
6 runs, 0 assertions, 0 failures, 0 errors, 0 skips
```

After:

```
6 runs, 7 assertions, 1 failures, 0 errors, 0 skips
```

This change bumps Capybara from 2.7.0 to 2.13.0 and includes the
required minitest assertion file in the test case. 🎉

Fix guide incorrectly refers to public/assets/images [ci ckip]

Updates incorrect documentation [ci skip]

Add documentation to use with_options anywhere in the same class [ci

Looking on code for this method it's clear that it's just returns `response.status` instead of full `response` object.
It's better to correct docs as probably lots of specs are relying on this behavior.

We are overriding it in `Time` and `ActiveSupport::TimeWithZone` so
there's no point in having it in the `DateAndTime::Compatibility`
module. Also add some docs for the `to_time` implementations.

Allow Time#to_time on frozen objects. Return frozen time rather than "RuntimeError: can't modify frozen Time"

Add secrets edit test

PR was merged before I could finished reviewing 😬

[ci skip]

In 9b654d47 some params munging was added to ensure that they were
set whenever `recognize_path` would call either a proc or callable
constraint. Since we no longer mutate the environment hash within
the method it's now unnecessary and actually causes params to leak
between route matches before checking constraints.

Fixes #28398.

Fix fragile test (`AssociationProxyTest#test_save_on_parent_saves_children`)

Remove implicit coercion deprecation of durations

Add documentation about signature_key for MessageEncryptor.new [ci skip]

If we run only following tests:

- test/cases/scoping/default_scoping_test.rb
- test/cases/associations_test.rb

```
$ cat Rakefile.test
require "rake/testtask"

ENV["ARCONN"] = "postgresql"

Rake::TestTask.new do |t|
  t.libs << "test"
  t.test_files = %w(
    test/cases/scoping/default_scoping_test.rb
    test/cases/associations_test.rb
  )
end
```

a test will fail:

```
$ bundle exec rake test -f Rakefile.test
/app/activesupport/lib/active_support/core_ext/enumerable.rb:20: warning: method redefined; discarding old sum
Using postgresql
Run options: --seed 11830

# Running:

.........................................................................................F................

Finished in 6.939055s, 15.2759 runs/s, 27.9577 assertions/s.

  1) Failure:
AssociationProxyTest#test_save_on_parent_saves_children [/app/activerecord/test/cases/associations_test.rb:185]:
Expected: 1
  Actual: 2

106 runs, 194 assertions, 1 failures, 0 errors, 0 skips
rake aborted!
Command failed with status (1)
/usr/local/bin/bundle:22:in `load'
/usr/local/bin/bundle:22:in `<main>'
Tasks: TOP => test
(See full trace by running task with --trace)
```

In #28083, change `self.use_transactional_tests` to `false`
but we forget to clean-up fixture.
However we don't have to disable transaction except a few tests.

In #28204 we deprecated implicit conversion of durations to a
numeric which represented the number of seconds in the duration
because of unwanted side effects with calculations on durations
and dates. This unfortunately had the side effect of forcing a
explicit cast when configuring third-party libraries like
expiration in Redis, e.g:

    redis.expire("foo", 5.minutes)

To work around this we've removed the deprecation and added a
private class that wraps the numeric and can perform calculation
involving durations and ensure that they remain a duration
irrespective of the order of operations.

Remove unused `@txn` variable

Make destroy command work within engines

Rename test of `app:update` to more appropriate name

This was added in c24c8852, removed in
b89ffe7f, and then (unintentionally?)
reintroduced in 2d7ae1b0.

`rails:update` was changed to `app:update` in 6fb31638.
Therefore, I think that it is better that the test name is also `app_update`.

Adding durations to `Time` instances is perfectly okay.

Add CHANGELOG entry for --skip-coffee [ci skip]

Was added in #25248 by @bluesh55

Remove obsolete warning about regular expression

This warning became obsolete when the regular expression was changed to
use `\z` instead of `\Z` in fce9c4e5.

    "-1234\n" =~ /\A[+-]?\d+\Z/ => 0
    "-1234\n" =~ /\A[+-]?\d+\z/ => nil

[ci skip]

This reverts commit 192db644, reversing
changes made to 98939553.

We can't sacrifice correctness for performance.

Instead of calling methods of Rails.application directly, we need to
use a method that is considered for the rails engine.