In Rails 3.2 dupping a `CollectionProxy` would dup it's `load_target` as
well. That functionality has been broken since the release of Rails 4.0.
I hit this in an application upgrade and wondered why duplicating a
CollectionProxy and assigning it to a variable stopped working.

When calling `dup` on a `CollectionProxy` only the owner (ex.
topic) was getting duplicated and the `load_target` would remain in tact
with it's original object ID. Dupping the `load_target` is useful for performing
a logging operation after records have been destroyed in a method.

For example:

```
def transfer_operation
  saved_replies = topic.replies

  topic.replies.clear

  saved_replies.each do |reply|
    user.update_replies_count!
  end
end
```

This change adds a `initialize_dup` method that performs a `deep_dup` on
the `@associatiation` so that the `load_target` is dupped as well.

Fixes #17117

Revert "Merge pull request #21233 from mtsmfm/disable-referential-integrity-without-superuser-privileges"

This reverts commit eeac6151, reversing
changes made to 5c40239d.

Reason: Broke the isolated tests.
https://travis-ci.org/rails/rails/builds/188721346

Because merging the association scope was removed.

`append_record` was added at 15ddd517 for not double adding the record.
But adding `append_record` (checking `@target.include?(record)`) caused
performance regression #27434. Instead of checking not double adding the
record, add a record to target before any callbacks loads the record.

Fixes #27434.

ref: 72c15572

- We must use `authors` fixture with `author_addresses` because of its foreign key constraint.
- Tests require PostgreSQL >= 9.4.2 because it had a bug about `ALTER CONSTRAINTS` and fixed in 9.4.2.

Currently if `CollectionProxy` has more than one new record,
`CollectionProxy#uniq` result is incorrect.

And `CollectionProxy#uniq` was aliased to `distinct` in a1bb6c8b.
But the `uniq` method and the `SELECT DISTINCT` method are different
methods. The doc in `CollectionProxy` is for the `SELECT DISTINCT`
method, not for the `uniq` method.

Therefore, reverting the alias in `CollectionProxy` to fix the
inconsistency and to have the both methods.

* Fixes TypeError when cache counter value equals nil

* Test case for counter cache on unloaded has_many association

- CollectionAssociation#select was removed in
  https://github.com/rails/rails/pull/25989 in favor of
  QueryMethods#select but it caused a regression when passing arguments
  to select and a block.
- This used to work earlier in Rails 4.2 and Rails 5. See gist
  https://gist.github.com/prathamesh-sonpatki/a7df922273473a77dfbc742a4be4b618.
- This commit restores the behavior of Rails 4.2 and Rails 5.0.0 to
  allow passing arguments and block at the same time but also deprecates
  it.
- Because, these arguments do not have any effect on the output of
  select when select is used with a block.
- Updated documentation to remove the example passing arguments and
  block at the same time to `CollectionProxy#select`.

This was caused by 6d0d83a3. While the
bug it's trying to fix is handled if the association is loaded in an
after_(create|save) callback, it doesn't handle any cases that load the
association before the persistence takes place (validation, or before_*
filters). Instead of caring about the timing of persistence, we can just
ensure that we're not double adding the record instead.

The test from that commit actually broke, but it was not because the bug
has been re-introduced. It was because `Bulb` in our test suite is doing
funky things that look like STI but isn't STI, so equality comparison
didn't happen as the loaded model was of a different class.

Fixes #26661.

assert [1, 3].includes?(2) fails with unhelpful "Asserting failed" message

assert_includes [1, 3], 2 fails with "Expected [1, 3] to include 2" which makes it easier to debug and more obvious what went wrong

Otherwise CollectionProxy's bang methdos cannot respect dirty target.

`#second`, `#third`, etc finder methods was added in 03855e79.
But the signature of these methods is inconsistent with the original
finder methods. And also the signature of `#first` and `#last` methods
is different from the original. This commit fixes the inconsistency.

Style/SpaceBeforeBlockBraces
Style/SpaceInsideBlockBraces
Style/SpaceInsideHashLiteralBraces

Fix all violations in the repository.

`#first`, `#second`, ..., `#last` methods respects dirty target. But
`#take` doesn't respect it. This commit fixes the inconsistent behavior.

When calling association.find RecordNotFound is now raised with the same argument as when we do it in Record.find (primary_key, id and model).

The current code base is not uniform. After some discussion,
we have chosen to go with double quotes by default.

These test cases tests exactly mutating loaded target.

This is not a test case.

Fixes #25732.

Ruby 2.4 unifies Fixnum and Bignum into Integer: https://bugs.ruby-lang.org/issues/12005

* Forward compat with new unified Integer class in Ruby 2.4+.
* Backward compat with separate Fixnum/Bignum in Ruby 2.2 & 2.3.
* Drops needless Fixnum distinction in docs, preferring Integer.

When same association is loaded in the model creation callback
The new object is inserted into association twice

If argument of `build_record` has key and value which is same as
default value of database, we should also except the key from
`create_scope` in `initialize_attributes`.
Because at first `build_record` initialize record object with argument
of `build_record`, then assign attributes derived from Association's scope.
In this case `record.changed` does not include the key, which value is
same as default value of database, so we should add the key to except list.

Fix #21893.

With `unscope!` called last, it undoes `where` constraints of the same
value when the `where` is chained after the `unscope`. This is what a
`rewhere` does. This is undesirable behavior.

The included tests demonstrate both the `unscope(...).where(...)`
behavior as well as the direct use of `rewhere(...)`.

This is in reference to #21955.

When I originally reviewed the #20317, I believe these changes were
present, but it appears that it was later updated so that they were
removed. Since Travis hadn't re-run the build, this slipped through.

`restrict_with_error` message will now respect owner’s human name in any locale [kuboon & Ronak Jangir]

Current implementation has a lot of utility methods that accept
reflection call a lot of methods on it and exit.

E.g. has_counter_cache?(reflection)

It causes confusion and inability to cache result of the method even
through it always returns the same result for the same reflection
object.
It can be done easier without access to the association context
by moving code into reflection itself.

e.g. reflection.has_counter_cache?

Reflection is less complex object than association so moving code there
automatically makes it simplier to understand.

Fixes #21082

remove extra space

Deep down in the association internals, we're calling `destroy!` rather
than `destroy` when handling things like `dependent` or autosave
association callbacks. Unfortunately, due to the structure of the code
(e.g. it uses callbacks for everything), it's nearly impossible to pass
whether to call `destroy` or `destroy!` down to where we actually need
it.

As such, we have to do some legwork to handle this. Since the callbacks
are what actually raise the exception, we need to rescue it in
`ActiveRecord::Callbacks`, rather than `ActiveRecord::Persistence` where
it matters. (As an aside, if this code wasn't so callback heavy, it
would handling this would likely be as simple as changing `destroy` to
call `destroy!` instead of the other way around).

Since we don't want to lose the exception when `destroy!` is called (in
particular, we don't want the value of the `record` field to change to
the parent class), we have to do some additional legwork to hold onto it
where we can use it.

Again, all of this is ugly and there is definitely a better way to do
this. However, barring a much more significant re-architecting for what
I consider to be a reletively minor improvement, I'm willing to take
this small hit to the flow of this code (begrudgingly).