* Add test for the new exception of delegate_missing_to

* Add a changelog entry

* Only check for nil if NoMethodError was raised

* Make method private

* Have to pass both target name and value

* Inline the re-raise

[Rafael Mendonça França + Anton Khamets]

Light grammar edits.

[ci skip]

[ci skip]

String#camelize was returning nil without any feedback when an
invalid option was passed as parameter. This update makes the method
to raises an ArgumentError when the option passed is invalid, similar
to what Ruby does for String#downcase (and others) in 2.4.1.

https://ruby-doc.org/core-2.4.1/String.html#method-i-downcase

Rails 5.1 introduce an `ActiveSupport::Duration::Scalar` class as
a wrapper around a numeric value as a way of ensuring a duration
was the outcome of an expression. However the implementation was
missing support for modulo operations. This commit adds support
for those operations and should result in a duration being
returned from expressions involving them.

Fixes #29603 and #29743.

PR #29163 introduced a change in behavior when a duration was
the denominator in a calculation - this was incorrect as dividing
by a duration should always return a `Numeric`. The behavior of
previous versions of Rails has been restored.

Fixes #29592.

The paragraphs retread ground covered by the title and the usage examples,
so let's just remove them.

[ Assain Jaleel & Kasper Timm Hansen ]

[ci skip]

[ Assain Jaleel & Kasper Timm Hansen ]

Rails.cache.write_multi foo: 'bar', baz: 'qux'

Plus faster `fetch_multi` with stores that implement `write_multi_entries`.
Keys that aren't found may be written to the cache store in one shot
instead of separate writes.

The default implementation simply calls `write_entry` for each entry.
Stores may override if they're capable of one-shot bulk writes, like
Redis `MSET`.

[ci skip]

[ci skip]

* Allow a default value to be declared for class_attribute

* Convert to using class_attribute default rather than explicit setter

* Removed instance_accessor option by mistake

* False is a valid default value

* Documentation

* Add ActiveSupport::CurrentAttributes to provide a thread-isolated attributes singleton

* Need to require first

* Move stubs into test namespace.

Thus they won't conflict with other Current and Person stubs.

* End of the line for you, whitespace!

* Support super in attribute methods.

Define instance level accessors in an included module such that
`super` in an overriden accessor works, akin to Active Model.

* Spare users the manual require.

Follow the example of concerns, autoload in the top level Active Support file.

* Add bidelegation support

* Rename #expose to #set. Simpler, clearer

* Automatically reset every instance.

Skips the need for users to actively embed something that resets
their CurrentAttributes instances.

* Fix test name; add tangible name value when blank.

* Try to ensure we run after a request as well.

* Delegate all missing methods to the instance

This allows regular `delegate` to serve, so we don't need bidelegate.

* Properly test resetting after execution cycle.

Also remove the stale puts debugging.

* Update documentation to match new autoreset

Previously calculations where the scalar is first would be converted
to a duration of seconds but this causes issues with dates being
converted to times, e.g:

    Time.zone = "Beijing"           # => Asia/Shanghai
    date = Date.civil(2017, 5, 20)  # => Mon, 20 May 2017
    2 * 1.day                       # => 172800 seconds
    date + 2 * 1.day                # => Mon, 22 May 2017 00:00:00 CST +08:00

Now the `ActiveSupport::Duration::Scalar` calculation methods will try
to maintain the part structure of the duration where possible, e.g:

    Time.zone = "Beijing"           # => Asia/Shanghai
    date = Date.civil(2017, 5, 20)  # => Mon, 20 May 2017
    2 * 1.day                       # => 2 days
    date + 2 * 1.day                # => Mon, 22 May 2017

Fixes #29160, #28970.

Previously apply_inflections would only use the :en uncountables
rather then the ones for the locale that was passed to pluralize or
singularize.

This changes apply_inflections to take a locale which it will use to
find the uncountables.

* Fix indentation.
* Add backticks.

* Remove trailing spaces.
* Add backticks around method and command.
* Fix indentation.

Send deprecation horizon and gem name as arguments to deprecation heavier handler, and make sure they are used for the ActiveSupport::Notifications message.

Support `:offset` in `Time#change` and `:zone` or `:offset`
in `ActiveSupport::TimeWithZone#change`.

Fixes #28723.

Was looking through #28402, and realized the CHANGELOG.md entry is in the wrong
place. Sorry we didn't catch this during code review 😢

[ci skip]

`fetch_values` was added to Hash in Ruby 2.3.0:
  https://bugs.ruby-lang.org/issues/10017

This patch adds an implemention for instances of HWAI, in line
with the existing definitions of `fetch` and `values_at`.

[ci skip]

An alternative to DeprecatedConstantProxy which works more transparently
with exceptions because it returns the object that the new constant
refers to rather than a proxy. This is then compatible with
`rescue OldException`.

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.

[ci skip]

Handle #to_time and memoization taking into account memoization, frozen state, and preserve_timezone flag.

In 4b685aad the regex in `titlelize` was updated to not match
apostrophes to better reflect the nature of the transformation.
Unfortunately this had the side effect of breaking capitalization
on the first word of a sub-string, e.g:

  >> "This was 'fake news'".titleize
  => "This Was 'fake News'"

This is fixed by extending the look-behind to also check for a
word character on the other side of the apostrophe.

Fixes #28312.