Merge pull request #35888 from lxxxvi/documentation_change_foreign_keys_to_bigint_in_association_basics

change `t.integer` to `t.bigint` where applicable

Improve log messages for #insert_all` / `#upsert_all` etc. methods

Update configuration of `app` directory and use oxford comma [skip ci]

When skipping duplicates in bulk insert on MySQL, avoid assigning an AUTONUMBER column when not specified

In #35077, `#insert_all` / `#upsert_all` / `#insert` / `#upsert` etc. methods are added. But Active Record logs only “Bulk Insert” log messages when they are invoked.

This commit improves the log messages to use collect words for how invoked them.

If `id` is an `AUTONUMBER` column, then my former strategy here of assigning `no_op_column` to an arbitrary column would fail in this specific scenario:

1. `model.columns.first` is an AUTONUMBER column
2. `model.columns.first` is not assigned in the insert attributes

I added three tests: the first test covers the actual error; the second test documents that this _isn't_ a problem when a value is given for the AUTONUMBER column and the third test ensures that this no-op strategy isn't secretly doing an UPSERT.

[ci-skip] Add 6.0 Release Notes for Active Record

Follow up of c9e4c848.

This refactors `execute_grouped_calculation` and slightly changes
generated GROUP BY queries, since I'd not prefer to repeat same
expression in SELECT and GROUP BY clauses.

Before:

```
SELECT COUNT(*) AS count_all, "topics"."author_name" AS topics_author_name, COALESCE(type, title) AS coalesce_type_title FROM "topics" GROUP BY "topics"."author_name", COALESCE(type, title)
```

After:

```
SELECT COUNT(*) AS count_all, "topics"."author_name" AS topics_author_name, COALESCE(type, title) AS coalesce_type_title FROM "topics" GROUP BY topics_author_name, coalesce_type_title
```

Although we generally don't guarantee to support Arel node constructed
by user itself, this also fixes #24207.

`values[:extending]` includes `NullRelation` if `null_relation?`.

Follow up of #35868.

Closes #19349.

Association loading isn't to be affected by scoping consistently

See https://github.com/rails/rails/pull/35873#issuecomment-480333333
for reference

[Prathamesh Sonpatki, bogdanvlviv]

Fix the deprecation warning about `config.active_job.return_false_on_aborted_enqueue`

Fix typo for touch later test description. laster -> later 

- It will return false in Rails 6.1 not 6.0. Also fixed the default
  value which is true for new applications.

Add missing `touch_all` delegation to relation

Follow up of #31513.

[ci skip] Mark ActiveRecord::TouchLater as private doc

Do not exclude paths in the global level of Code Climate

Follow-up of 5c71000d, #29834, and #30271.

Currently, preloading and eager loading are not to be affected by
scoping, with the exception of `unscoped`.

But non eager loaded association access is still affected by scoping.

Although this is a breaking change, the association loading will work
consistently whether preloaded / eager loaded or not.

Before:

```ruby
Post.where("1=0").scoping do
  Comment.find(1).post                   # => nil
  Comment.preload(:post).find(1).post    # => #<Post id: 1, ...>
  Comment.eager_load(:post).find(1).post # => #<Post id: 1, ...>
end
```

After:

```ruby
Post.where("1=0").scoping do
  Comment.find(1).post                   # => #<Post id: 1, ...>
  Comment.preload(:post).find(1).post    # => #<Post id: 1, ...>
  Comment.eager_load(:post).find(1).post # => #<Post id: 1, ...>
end
```

Fixes #34638.
Fixes #35398.

We use only RuboCop in Code Climate and exclude paths are specified in
RuboCop's setting.

The global level excludes paths should not be specified to match the
behavior of local and CodeClimate.

https://github.com/sporkmonger/addressable/pull/270

This is completely same with `test_last`.

Stash `left_joins` into `joins` to deduplicate redundant LEFT JOIN

fix typo in the guides (use Rails instead of rails) [ci skip]

Originally the `JoinDependency` has the deduplication for eager loading
(LEFT JOIN). This re-uses that deduplication for `left_joins`.

And also, This makes left join order into part of joins, i.e.:

Before:

```
association joins -> stash joins (eager loading, etc) -> string joins -> left joins
```

After:

```
association joins -> stash joins (eager loading, left joins, etc) -> string joins
```

Now string joins are able to refer left joins.

Fixes #34325.
Fixes #34332.
Fixes #34536.

Add documentation for 'after_save_commit' [ci skip]

Adds 'detach_from' to 'ActiveSupport::Subscriber' to detach a subscriber from a namespace.