[Rafael Mendonça França + Robin Dupret]

Remove text default treated as an empty string in non-strict mode

Revert "`sql_for_insert` returns values for passing to `exec_insert`"

Remove unnecessary `select` method for `CollectionProxy`

run `before_configuration` callbacks as soon as application constant inherits from Rails::Application

This reverts #23067. #23067 is for propagating `pk` value from
`sql_for_insert` to `exec_insert` (avoiding extra query for pg adapter).
Now `exec_insert` includes `sql_for_insert` since #26002 therefore this
propagating is no longer needed.

Sqlite3 Migration Error Fixed (issue #26087)

run `before_configuration` callbacks as soon as application constant inherits from Rails::Application

Until Rails 4.1, `before_configuration` run as soon as the application constant
inherits from `Rails::Application`.
However, in d25fe31c, it has been modified to
run at instantiation process.

This modify to `before_configuration` is run at same timing as to Rails 4.1.

Fixes #19880

Strict mode controls how MySQL handles invalid or missing values in
data-change statements such as INSERT or UPDATE. If strict mode is not
in effect, MySQL inserts adjusted values for invalid or missing values
and produces warnings.

```ruby
  def test_mysql_not_null_defaults_non_strict
    using_strict(false) do
      with_mysql_not_null_table do |klass|
        record = klass.new
        assert_nil record.non_null_integer
        assert_nil record.non_null_string
        assert_nil record.non_null_text
        assert_nil record.non_null_blob

        record.save!
        record.reload

        assert_equal 0,  record.non_null_integer
        assert_equal "", record.non_null_string
        assert_equal "", record.non_null_text
        assert_equal "", record.non_null_blob
      end
    end
  end
```

It is inconsistent with other types that only text/blob defaults treated
as an empty string. This commit fixes the inconsistency.

Preserve readonly flag only for readonly association

Remove unnecessary ordinal methods for collection association

Remove `sanitize_conditions` and use `sanitize_sql` instead of `sanitize_conditions`

Merge pull request #26197 from kamipo/remove_unnecessary_test_sql_for_insert_with_returning_disabled

Remove unnecessary `test_sql_for_insert_with_returning_disabled`

Updates Active Job guide on default runner.

The immediate runner is no longer default, the async adapter is.

i18n documentation for required belongs_to message

invalid column type
    /activerecord/lib/active_record/connection_adapters
    /abstract/schema_definitions.rb:306
    type = type.to_sym

Changed to the following to handle nil case:
    type = type.to_sym if type

Added regression test for this case:
  /activerecord/test/cases/migration_test.rb:554
  if current_adapter?(:SQLite3Adapter)
    def test_allows_sqlite3_rollback_on_invalid_column_type
      Person.connection.create_table :something, force: true do |t|
        t.column :number, :integer
        t.column :name, :string
        t.column :foo, :bar
      end
      assert Person.connection.column_exists?(:something, :foo)
      assert_nothing_raised { Person.connection.remove_column :something, :foo, :bar }
      assert !Person.connection.column_exists?(:something, :foo)
      assert Person.connection.column_exists?(:something, :name)
      assert Person.connection.column_exists?(:something, :number)
    ensure
      Person.connection.drop_table :something, if_exists: true
    end
  end

Currently `CollectionProxy` inherits `Relation` therefore we can use
its own methods rather than delegating to collection association.

When you don't explicitly provide `optional: true` to a `belongs_to`
definition, rails adds a validation to ensure presence of the
`belongs_to` validation.

However, when the validation is added, it is added with a message key of
`:required`, which was not documented in the "Translations for Active
Record Models" section of the i18n guides.

Here are the lines that add the `:required` message:
https://github.com/rails/rails/blob/c3e3577f9d5058382504773bf0d32afa15cb131e/activerecord/lib/active_record/associations/builder/belongs_to.rb#L136-L138

This commit adds the "non-optional association" validation to the table,
so rails users know how to override the message for this validation. The
default message is "must exist".

Currently `CollectionProxy` inherits `Relation` and `Relation` includes
`QueryMethods`. This method is completely duplicated.

https://github.com/rails/rails/blob/v5.0.0/activerecord/lib/active_record/relation/query_methods.rb#L271-L275

Because `sql_for_insert` is only called in `use_insert_returning?` is
true since #26002.

Those methods are only using inside this module and by a private method
so they all should be private.

Since e852daa6 only the verb methods
where extracting the defaults options. It was merged a fix for the
`root` method in 31fbbb7f but `match`
was still broken since `:defaults` where not extracted.

This was causing routes defined using `match` and having the `:defaults`
keys to not be recognized.

To fix this it was extracted a new private method with the actual
content of `match` and the `:defaults` extracting was moved to `match`.

Because `sanitize_conditions` protected method is only used in one place.

Fix #26187

As "discussed" in #26187 I added the route that magically disappeared again.

Fix diffrent naming in getting_started.md

I've noticed that once `<h1>Editing article</h1>` L1157 was the title and then later on it's `<h1>Edit article</h1>` L1358 which kind of makes more sense...

[ci skip]

Fix error message for out of range byte size integer value for consistency

Remove parameter "options = nil" for #clear

Fix link in Rails 5.0 Release Note 

`pluck` should use `records` (`load_target`) when `loaded?` is true

Fix does_not_support_reverse? to find sql functions with commas in nested brackets

refactor `CommandsTasks`

`sql_for_insert` should be called inside `exec_insert`

Fix inconsistent the signature of finder methods for collection association

Start documenting ActionController::TestCase again

- Rails 5 changed interface for passing arguments to request methods to
  keyword args for AC::TestCase but also hid the documentation.
- But existing AC::TestCase tests need the new documentation about
  keyword args. So resurrected documentation and added a note about not
  using this for new tests.
- The guides and other documentation is already updated to use
  `ActionDispatch::IntegrationTest`.

[Matthew Draper, Prathamesh Sonpatki]