The commit replaces the `Man` model used in tests with a `Human` model. It
also replaces the existing `Human` model with a `SuperHuman` model
inheriting from `Human`.

While this may seem like a cosmetic change, I see it as more of an
inclusivity change. I think it makes sense for a number of reasons:

* Prior to this commit the `Human` model inherited from `Man`. At best
  this makes no sense (it should be the other way around). At worst it
  is offensive and harmful to the community.
* It doesn't seem inclusive to me to have exclusively male-gendered
  examples in the codebase.
* There is no particular reason for these examples to be gendered.
* `man` is hard to grep for, since it also matches `many, manager,
  manual, etc`

For the most part this is a simple search and replace. The one exception
to that is that I had to add the table name to the model so we could use
"humans" instead of "humen".

In using HABTM, join middle table alias is combined with the associated
models name without sort, while middle table name is combined with those
models name with sort.

Fixes #36742.

https://buildkite.com/rails/rails/builds/61358#a78ee50e-30b5-48a2-858f-63eba287d919/1290-1298

This reverts commit a1ee4a9f.

Even if a1ee4a9f is applied, CI is still flakiness.

https://buildkite.com/rails/rails/builds/61252#2c090afa-aa84-4a2b-8b81-9f09219222c6/994-1005
https://buildkite.com/rails/rails/builds/61252#2e55bf83-1bde-44a2-a4f1-b5c3f6820fb4/929-938

Failing tests by whether schema cache is filled or not, it actually
means that whether SCHEMA SQLs are executed or not is not target for the
tests.

So I've reverted commit a1ee4a9f which filling schema cache before
`assert_no_queries`, and replace `assert_no_queries` to
`assert_queries(0)`.

Currently we sometimes find a redundant begin block in code review
(e.g. https://github.com/rails/rails/pull/33604#discussion_r209784205).

I'd like to enable `Style/RedundantBegin` cop to avoid that, since
rescue/else/ensure are allowed inside do/end blocks in Ruby 2.5
(https://bugs.ruby-lang.org/issues/12906), so we'd probably meets with
that situation than before.

Starting in Rails 5.0.0 and still present in Rails 5.2.1, `singular_ids`
got memoized and didn't reload after more items were added to the
relation.

Although 19c80718 happens to fix the issue, it only adds tests for
`has_many` relations while this bug only affected
`has_and_belongs_to_many` relations.

This commit adds a regression test to ensure it never happens again with
`habtm` relations.

Ensures #34179 never gets reproduced.

`developers.name desc` was added at d59f3a78, but any test case isn't
failed even if the `developers.name desc` is removed since all tested
developers are consistently ordered on both `name` and `id`.

I changed one developers creation ordering to ensure to test that
`project.developers` is ordered by `developers.name desc`.

Follow up 45be690f.

Somehow calling `define_attribute_methods` in `build`/`new` sometimes
causes the `table_exists?` query.

To address CI flakiness due to `assert_no_queries` failure, ensure
`define_attribute_methods` before `assert_no_queries`.

Follow up 811be477.

`test_update_does_not_run_sql_if_record_has_not_changed` would pass
without #18501 since `assert_queries` ignores BEGIN/COMMIT unless
`ignore_none: true` is given.

Since #32647, empty BEGIN/COMMIT is ommited. So we no longer need to use
`assert_queries(0)` to ignore BEGIN/COMMIT in the queries.

Since fe9547b6, numericality validator would parse raw value only when a
value came from user to work type casting to a value from database.

But that was caused a regression that the validator would work against
getter value instead of parsed raw value, a getter is sometimes
customized by people. #33550

There we never guarantees that the value before type cast was going to
the used in this validation (actually here is only place that getter
value might not be used), but we should not change the behavior unless
there is some particular reason.

The purpose of fe9547b6 is to work type casting to a value from
database. We could achieve the purpose by using `read_attribute`,
without using getter value.

Fixes #33550.

This autocorrects the violations after adding a custom cop in
3305c78dcd.

Closes #31998

This reverts commit 3420a145, reversing
changes made to afb66a5a.

".. with __dir__ we can restore order in the Universe." - by @fxn

Related to 5b8738c2

Fixes #24032

```
go get -u github.com/client9/misspell/cmd/misspell
misspell  -w -error -source=text .
```

The idea of `class_name` as an option of reflection is that passing a
string would allow us to lazy autoload the class.

Using `belongs_to :client, class_name: Customer` is eagerloading models more than necessary
and creating possible circular dependencies.

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.

Using Constant and symbol class_name option for associations are valid but raises exception on HABTM associations.
There was a test case which tries to cover symbol class_name usage but doesn't cover correctly. Fixed both symbol usage and constant usage as well.

These are all working as expected now;
```
  has_and_belongs_to_many :foos, class_name: 'Foo'
  has_and_belongs_to_many :foos, class_name: :Foo
  has_and_belongs_to_many :foos, class_name: Foo
```

Closes #23767

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

Style/SpaceBeforeBlockBraces
Style/SpaceInsideBlockBraces
Style/SpaceInsideHashLiteralBraces

Fix all violations in the repository.

Hash syntax auto-correcting breaks alignments. 411ccbda

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

`AssociationQueryHandler` requires `association` initialized
`TableMetadata` even if `table_name == arel_table.name`.

Fixes #25689.

Actually schema dumper/creation supports composite primary key (#21614).
Therefore it should not show the warning about composite primary key in
connection adapter.

This change moves the warning to `AttributeMethods::PrimaryKey` and
suppress the warning for habtm join table.

Fixes #25388.