* Reduce allocations in transition_table

* Use predicate symbol? instead of is_a?

Clear Resolvers' cache after AVLogSubscriberTest tests

Addresses the build failure below:
https://buildkite.com/rails/rails/builds/70853#29647167-4db2-4810-810e-d2c3a4e6dcf8

* This pull request addresses this error.

```
$ bin/test test/template/log_subscriber_test.rb test/template/test_case_test.rb -n "/^(?:AVLogSubscriberTest#(?:test_render_collection_template)|ActionView::HelperInclusionTest#(?:test_helper_class_that_is_being_tested_is_always_included_in_view_instance))$/" --seed 54118
Run options: -n "/^(?:AVLogSubscriberTest#(?:test_render_collection_template)|ActionView::HelperInclusionTest#(?:test_helper_class_that_is_being_tested_is_always_included_in_view_instance))$/" --seed 54118

.E

Error:
ActionView::HelperInclusionTest#test_helper_class_that_is_being_tested_is_always_included_in_view_instance:
ActionView::Template::Error: undefined method `_test__customer_erb___3224798146126036163_10260' for #<#<Class:0x00005653f1b35768>:0x00005653f1b348e0>
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/base.rb:276:in `_run'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/template.rb:182:in `block in render'
    /home/yahonda/src/github.com/rails/rails/activesupport/lib/active_support/notifications.rb:205:in `instrument'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/template.rb:384:in `instrument_render_template'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/template.rb:180:in `render'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/renderer/collection_renderer.rb:186:in `block in collection_with_template'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/renderer/collection_renderer.rb:66:in `block in each_with_info'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/renderer/collection_renderer.rb:66:in `each'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/renderer/collection_renderer.rb:66:in `each_with_info'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/renderer/collection_renderer.rb:177:in `each'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/renderer/collection_renderer.rb:177:in `map'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/renderer/collection_renderer.rb:177:in `collection_with_template'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/renderer/collection_renderer.rb:159:in `block (2 levels) in render_collection'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/renderer/partial_renderer/collection_caching.rb:21:in `cache_collection_render'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/renderer/collection_renderer.rb:158:in `block in render_collection'
    /home/yahonda/src/github.com/rails/rails/activesupport/lib/active_support/notifications.rb:203:in `block in instrument'
    /home/yahonda/src/github.com/rails/rails/activesupport/lib/active_support/notifications/instrumenter.rb:24:in `instrument'
    /home/yahonda/src/github.com/rails/rails/activesupport/lib/active_support/notifications.rb:203:in `instrument'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/renderer/collection_renderer.rb:144:in `render_collection'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/renderer/collection_renderer.rb:116:in `render_collection_with_partial'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/renderer/renderer.rb:75:in `render_partial_to_object'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/renderer/renderer.rb:27:in `render_to_object'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/renderer/renderer.rb:22:in `render'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/helpers/rendering_helper.rb:38:in `block in render'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/base.rb:306:in `in_rendering_context'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/helpers/rendering_helper.rb:34:in `render'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/test_case.rb:205:in `render'
    /home/yahonda/src/github.com/rails/rails/actionview/test/template/test_case_test.rb:126:in `render_from_helper'
    /home/yahonda/src/github.com/rails/rails/actionview/test/fixtures/test/_from_helper.erb:1:in `__home_yahonda_src_github_com_rails_rails_actionview_test_fixtures_test__from_helper_erb___900298654238864924_10340'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/base.rb:276:in `_run'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/template.rb:182:in `block in render'
    /home/yahonda/src/github.com/rails/rails/activesupport/lib/active_support/notifications.rb:205:in `instrument'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/template.rb:384:in `instrument_render_template'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/template.rb:180:in `render'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/renderer/partial_renderer.rb:285:in `block in render_partial_template'
    /home/yahonda/src/github.com/rails/rails/activesupport/lib/active_support/notifications.rb:203:in `block in instrument'
    /home/yahonda/src/github.com/rails/rails/activesupport/lib/active_support/notifications/instrumenter.rb:24:in `instrument'
    /home/yahonda/src/github.com/rails/rails/activesupport/lib/active_support/notifications.rb:203:in `instrument'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/renderer/partial_renderer.rb:280:in `render_partial_template'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/renderer/partial_renderer.rb:271:in `render'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/renderer/renderer.rb:84:in `render_partial_to_object'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/renderer/renderer.rb:27:in `render_to_object'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/renderer/renderer.rb:22:in `render'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/helpers/rendering_helper.rb:38:in `block in render'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/base.rb:306:in `in_rendering_context'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/helpers/rendering_helper.rb:34:in `render'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/test_case.rb:205:in `render'
    /home/yahonda/src/github.com/rails/rails/actionview/lib/action_view/test_case.rb:122:in `render'
    /home/yahonda/src/github.com/rails/rails/actionview/test/template/test_case_test.rb:136:in `block in <class:HelperInclusionTest>'

bin/test test/template/test_case_test.rb:132

Finished in 0.076637s, 26.0970 runs/s, 39.1454 assertions/s.
2 runs, 3 assertions, 0 failures, 1 errors, 0 skips
$
```

Refer #36189 for the similar fix

Autosave collection associations exactly once

Generate abstract class when generating scaffold in another database

This PR ensures that when you're generating a scaffold or model and that
model should belong to another database it will create an abstract class
if it doesn't already exist.

The new abstract class will ensure that the new model inherits from that
class, but will not be deleted if the scaffold is deleted. This is
because Rails can't know if you have other models inheriting from that
class so we don't want to revoke that if the scaffold is destroyed.

If the abstract class already exists it won't be created twice. If the
options for `parent` are set, the generator will use that as the
abstract class instead of creating one. The generated abstract class
will add the writing connection automatically, users need to add the
reading connection themselves as Rails doesn't know which is the reading
connection.
Co-authored-by: NJohn Crepezzi <john.crepezzi@gmail.com>

The model global `read_attribute_for_validation` is not fit for some
validators (specifically for numericality validator).

To allow per-validator customization for attribute value, it extracts
`read_attribute_for_validation` in `EachValidator`.

Correct engine generator docs

Use standard config/application.rb in plugin dummy

The `config/application.rb` file of a plugin test dummy app should be
the same as in a standard Rails app, with the exception of an additional
`require` statement to load the plugin itself.  However, prior to this
commit, the plugin generator used a specialized template for a portion
of this file, which tended to drift out-of-sync with the standard app
generator's template.  Specifically, this drift could result in missing
`require` statements of newer Rails frameworks when the plugin generator
was run with any `--skip-xxxx` option.

This commit changes the plugin generator to insert its additional
`require` statement into the standard `config/application.rb` file
generated by the app generator.

`type_for_attribute` was added (extracted from `column_for_attribute`)
in `ModelSchema` at c93dbfef, I sometimes had expected that both
`column_for_attribute` and `type_for_attribute` exists in `ModelSchema`,
but `column_for_attribute` had existed in `AttributeMethods` even though
it's not very relevant to attribute methods (getting column object is no
longer useful for most end users since type object is separated from
column object, by the way).

So I've moved `column_for_attribute` to the same place with
`type_for_attribute` to less confusion a bit.

Followup to 17a4ec1c.

Move Path::Pattern factories into test helper

Fix flakey test due to non-deterministic order

`Pattern#from_sting` was introduced in bb207ea7 to support creating
patterns from strings in tests (removing a conditional in the initialize
method that had been there only for the sake of those tests).

`Pattern#build` was introduced in 947ebe9a, and was similarly used only
in tests.

My understanding is that [`Mapping#path`][path] is the only place where
we initialize a `Path::Pattern` in library code.

Since these two methods appear to be used only in tests, this
commit moves them out of the class and into a test helper.

My reasoning for doing this is that I am doing some performance work
that may involve a modification to how `Path::Pattern`s get initialized,
and I will have more confidence in that work if I know for sure that
these methods are test helpers that can be modified freely.

[path]: https://github.com/rails/rails/blob/master/actionpack/lib/action_dispatch/routing/mapper.rb#L192-L194

Add back support for other syntax highlighting [skip-ci]
Co-authored-by: NJonathan Hefner <jonathan@hefner.pro>

Example failure: https://buildkite.com/rails/rails/builds/70840#d213df74-a2e6-45e5-8302-d75a6c31f700/1021-1033

The test's assertion expects the authors to be ordered by ID, but that
order is not guaranteed without an explicit sort.

Engines are not applications, indeed 'Application < Engine', so it's the other way round.
The difference can be confusing anyway, so we should make sure the documentation is clear.

Similar with #39463.

Originally #39882 is intended to remove `decorate_matching_attribute_type`
but leave `decorate_attribute_type` at that point, but in the
disscussion in #39882, to demonstrate removing `AttributeDecorators`
module, I've removed all decoration methods.

I wrote user-defined type decoration as inline, I wasn't sure that is
valid (meaningful) usage (that is a reason why I wasn't in a hurry to
remove that method), as I said at https://github.com/rails/rails/pull/39882#discussion_r457750898.

In #39897 and #39902, `enum` also need to support user-defined type
decoration, so I've decided to add back `decorate_attribute_type` as
before #39882.

touch parent model when an attachment is purged

Currently `delete` is used on the `purge` and `purge_later` methods,
that prevent any callbacks to be triggered which causes the parent
model to not be updated when an attachment is purged. This behaviour
cause issues on some caching strategies as reported here: https://github.com/rails/rails/issues/39858

Changes:

* Add `record&.touch` on `attachment#purge`
* Add `record&.touch` on `attachment#purge_later`
* Remove extra blank line on attachment.rb
* Add tests which are failing before this change and pass after the change

When using Rouge's Console lexer it expects all ignored line breaks to
be proceeded by a backslash. In this code block as we are switching to
Mysql's command line which doesn't need a backslash. This leads to the
lexer breaking and all the lines ending up in a confusing mess.

However the sql syntax actually works much better for this block
anyway.

This line here shows why what we were trying to do wouldn't work with
Rouge:
https://github.com/rouge-ruby/rouge/blob/844c0eeddf7626605fa04b901df6c15c953811d6/lib/rouge/lexers/console.rb#L106

We recently switched to use Rouge for syntax highlighting in the guides,
but in doing so we dropped support for highlighting the following
syntaxes, which are used in the guides:

apache
diff
json
markdown
nginx
scss
xml

There was also css and the "javascript" alias, but @eugeneius already
addressed these two.

They syntaxes were all being converted to "plaintext". This change allows
all the lexers mentioned above as well as any other lexers available
through Rouge.

We have deliberately decided to not support passing rougue custom lexer
options from the code fences. Instead any lexer options that are needed
can be set by adding an entry to the lexer_language case statement. This
should lead to more consistency in formatting and gives us more control
over what Rogue options are allowed.

Fix path_parameters key type inconsistency in ActionController::TestCase

Fix option not being passed with fetch_multi

In redis cache store, options to `fetch_multi` are passed correctly to
`write_multi` but not to `read_multi`. This causes cache always to be missed
when passing `namespace` option to it.

prevents redundant memcached compression

- Disables Dalli compression in MemCacheStore.
- Fixes issue where redundant compression in Dalli can cause values to
either be compressed twice, or compressed when they fall below the
specified compression threshold.

If request format is JSON, keys are converted to Strings, so we have to convert them to Symbols.

Build symbols descending from stars with regexp

`attr.name` is already normalized as a string and alias resolved.

Ref #39881.

Before this commit we initialized all Symbols with the default regexp,
then later on reassigned any symbols descending from stars with either
their regexp from `@requirements` or the default greedy regexp.

With this commit we initialize all Symbols descending from Stars with
the greedy regexp at parse time. This allows us to get rid of the star
branch in path/pattern, since any regexps from `@requirements` will
already have been set in the symbol branch of this code.

This is essentially an alternate version of #38901. Getting rid of the
extra branch makes some performance work I am doing a bit easier, plus
it saves us a few method calls. Also the constant saves us from creating
the same regexp multiple times, and it is nice to give that regexp a
name.

Fix argument naming in `AbstractStore#set_cookie`

The signature in Rack https://github.com/rack/rack/blob/master/lib/rack/session/abstract/id.rb#L415 expects a response as the second argument

Add label attribute to <option> from include_blank

The `:include_blank` option of various `<select>`-related helpers causes
an `<option>` element with no content to be rendered.  However, the
[HTML spec] says that unless an `<option>` element has a `label`
attribute (which must be non-empty), its content must be "Text that is
not inter-element whitespace."

In #24923, this issue was addressed for `select_tag` by adding a `label`
attribute to the `<option>`.  This commit addresses the issue in the
same manner for `FormBuilder#select` and various date / time select
helpers.

[HTML spec]: https://html.spec.whatwg.org/multipage/form-elements.html#the-option-element