* Added `class_names` helper to create a CSS class value with conditional classes.
*Joel Hawksley*, *Aaron Patterson*
* Add support for conditional values to TagBuilder.
*Joel Hawksley*
* `ActionView::Helpers::FormOptionsHelper#select` should mark option for `nil` as selected.
```ruby
@post = Post.new
@post.category = nil
# Before
select("post", "category", none: nil, programming: 1, economics: 2)
# =>
#
# After
select("post", "category", none: nil, programming: 1, economics: 2)
# =>
#
```
*bogdanvlviv*
* Log lines for partial renders and started template renders are now
emitted at the `DEBUG` level instead of `INFO`.
Completed template renders are still logged at the `INFO` level.
*DHH*
* ActionView::Helpers::SanitizeHelper: support rails-html-sanitizer 1.1.0.
*Juanito Fatas*
* Added `phone_to` helper method to create a link from mobile numbers.
*Pietro Moro*
* annotated_source_code returns an empty array so TemplateErrors without a
template in the backtrace are surfaced properly by DebugExceptions.
*Guilherme Mansur*, *Kasper Timm Hansen*
* Add autoload for SyntaxErrorInTemplate so syntax errors are correctly raised by DebugExceptions.
*Guilherme Mansur*, *Gannon McGibbon*
* `RenderingHelper` supports rendering objects that `respond_to?` `:render_in`.
*Joel Hawksley*, *Natasha Umer*, *Aaron Patterson*, *Shawn Allen*, *Emily Plummer*, *Diana Mounter*, *John Hawthorn*, *Nathan Herald*, *Zaid Zawaideh*, *Zach Ahn*
* Fix `select_tag` so that it doesn't change `options` when `include_blank` is present.
*Younes SERRAJ*
Please check [6-0-stable](https://github.com/rails/rails/blob/6-0-stable/actionview/CHANGELOG.md) for previous changes.