References #19565.

make `ENV` a required argument

Set the content-type to `text/html` if the options[:html] is true

In this commit, we set the content-type to `text/html` in AbstractController if the `options[:html]` is true so that we don't include ActionView::Rendering into ActionController::Metal to set it properly.

I removed the if `options[:plain]` statement because `AbstractController#rendered_format` returns `Mime::TEXT` by default.

* A string in the example lacked quotes.

* The tests asserted stuff about :last_name, whereas
  test params do not have that key.

* But, the first one passed, why? After hitting my head against
  the wall and doing some obscure rituals realized the new
  #require had an important typo, wanted to iterate over the
  array argument (key), but it ran over its own hash keys
  (method #keys).

* Modified the test to prevent the same typo to happen again.

* The second test assigned to an unused variable safe_params
  that has been therefore removed.

* Grammar of the second test description.

* Since I was on it, reworded both test descriptions.

Closes #21418.

Previously schema names were not quoted. This leads to issues when a
schema names contains a ".". Methods in `schema_statements.rb` should
quote user input.

These changes rephrases the description with better explanation of step by step process.

[Feature] params.require accepts array of parameters that should be present or raise error

This PR adds ability to accept arrays which allows you to require multiple values in one method. so instead of this:

```ruby
params.require(:person).require(:first_name)
params.require(:person).require(:last_name)
```

Here it will be one line for each params, so say if I require 10params, it will be 10lines of repeated code which is not dry. So I have added new method which does this in one line:

```ruby
params.require(:person).require([:first_name, :last_name])
```

Comments welcome

[ci skip]

Currently the `#tables` method does not make use of the `name`
argument and always returns all the tables in the schema search
path. However the docs suggest different behavior.

While we should porbably adjust the implementation to provide this
behavior, let's make the docs right for now (also for `4-2-stable`) and
then implement the behavior on `master`.

fix reference to undefined variable in email testing guide [ci skip]

Support for custom regular expression for number_to_delimeted

- Extracted `DELIMITED_REGEX` to `delimited_regex` method and made use of  user passed `options[:delimited_regex]` if available. Changed `DELIMITED_REGEX` to `DEFAULT)DELIMITED_REGEX` to signify what it means.
- Added tests for number to delimited and number to currency in both actionview and activesupport.

Changes

Changes

Code cleanup

10X speed improvements for AS::Dependencies.loadable_constants_for_path

Fix Configuring Active Record  [ci skip]

When the autoload_paths start to grows, this methods is quite a hotspot

>> ActiveSupport::Dependencies.autoload_paths.size
=> 49

>> Benchmark.ips { |x| x.report('baseline') { ActiveSupport::Dependencies.loadable_constants_for_path(File.expand_path('app/models/shop')) }}
Calculating -------------------------------------
            baseline    90.000  i/100ms
-------------------------------------------------
            baseline      1.073k (±20.2%) i/s -      4.950k

After the patch

Calculating -------------------------------------
             patched   883.000  i/100ms
-------------------------------------------------
             patched     11.050k (±19.7%) i/s -     50.331k

remove link to outdated article in plugins guide [ci skip]

linked article is a description of the plugins in Rails 2.1.

This reverts commit cae2b5bb.

I am an idiot.

eventually we'll remove this instance variable, but this is the first
step

we're storing the value in the headers hash, so lets just store the
value in one place.

Modules should be using the API that the abstract modules use so that we
can move these modules between implementations

cookies are always stored as a string in the header hash, so it will not
need to be joined.

eventually we will refactor this to not know about header hashes

Follow up to #21384.

Merge pull request #21384 from jeremyf/updating-ActionController-TestSession-to-behave-as-a-hash-with-indifferent

Updating TestSession to access with indifference

remove require of files under support that do not use

no more require minitest mock here

Cleanup for `ActionDispatch::Http::Parameters` - no need for required libraries
and remove not used private method.

Apparently this method was used in `ActionDispatch::Http::Request` - fixed
by calling `Request::Utils` explicitly (as was done in other parts of the codebase)