Incompatible settings are included in the settings set by `load_defaults`.
So, I think that target version should be updated by a user when becomes
available, and should not be updated with `app:update`.

This is similar to #30700 which ensures the `--quiet` option of `rails new`
is respected by the `MasterKeyGenerator` (missing from #30067).

Before this commit, running `rails new app --force` would still prompt the
user what to do with the conflict in `config/master.key`:

```
              …
   identical  config/locales/en.yml
    conflict  config/master.key
Overwrite /Users/claudiob/Desktop/pizza/config/master.key? (enter "h" for help) [Ynaqdh]
```

After this commit, `config/master.key` is overwritten:

```
           …
identical  config/locales/en.yml
    force  config/master.key
   append  .gitignore
```

The newly added test generates an app and then generates it again with
`--force`. Without this commit, the test would just wait forever for user
input.

Fixes #31917

- Add set_locale to detect suitable locale
- Make feature compatible with Rails 5.x

down is only called with a block from the rake tasks where it passes a
`SCOPE`. Technically this was tested but since we don't run all the
migrations we're not actually testing the down works with a `SCOPE`. To
ensure we're testing both we can run `db:migrate` again to migrate users
and then run `down` with a scope to test that only the bukkits migration
is reverted.

Updates test to prevent having to fix regressions like we did in
4d4db4c8.

Rails has some support for multiple databases but it can be hard to
handle migrations with those. The easiest way to implement multiple
databases is to contain migrations into their own folder ("db/migrate"
for the primary db and "db/seconddb_migrate" for the second db). Without
this you would need to write code that allowed you to switch connections
in migrations. I can tell you from experience that is not a fun way to
implement multiple databases.

This refactoring is a pre-requisite for implementing other features
related to parallel testing and improved handling for multiple
databases.

The refactoring here moves the class methods from the `Migrator` class
into it's own new class `MigrationContext`. The goal was to move the
`migrations_paths` method off of the `Migrator` class and onto the
connection. This allows users to do the following in their
`database.yml`:

```
development:
  adapter: mysql2
  username: root
  password:

development_seconddb:
  adapter: mysql2
  username: root
  password:
  migrations_paths: "db/second_db_migrate"
```

Migrations for the `seconddb` can now be store in the
`db/second_db_migrate` directory. Migrations for the primary database
are stored in `db/migrate`".

The refactoring here drastically reduces the internal API for migrations
since we don't need to pass `migrations_paths` around to every single
method. Additionally this change does not require any Rails applications
to make changes unless they want to use the new public API. All of the
class methods from the `Migrator` class were `nodoc`'d except for the
`migrations_paths` and `migrations_path` getter/setters respectively.

pg-1.0.0 is just released and most Gemfiles don't restrict
it's version. But the version is checked when connecting to
the database, which leads to the following error:

Gem::LoadError: can't activate pg (~> 0.18), already activated pg-1.0.0

See also this pg issue:
https://bitbucket.org/ged/ruby-pg/issues/270/pg-100-x64-mingw32-rails-server-not-start

Preparation for pg-1.0 was done in commit f28a3310,
but the pg version constraint was not yet relaxed.

  Remove `AppGeneratorTest#test_active_storage_install`.
  The test is added by 67db41aa,
  since #31534 this test doesn't test anything.

  Remove redundant assertions in `SharedGeneratorTests`.
  These assertions is added by 4a835aa3.
  Follows 67db41aa, #31534.

Instead of providing a configuration option to set the hash function,
switch to SHA-1 for new apps and allow upgrading apps to opt in later
via `new_framework_defaults_5_2.rb`.

Enabling this option in new_framework_defaults_5_2.rb didn't work
before, as railtie initializers run before application initializers.

Using `respond_to?` to decide whether to set the option wasn't working
either, as `ActiveSupport::OrderedOptions` responds to any message.

Ref: http://docs.seattlerb.org/minitest/Minitest/Result.html#attribute-i-klass

`filtered_results` returns an instance of `Minitest::Result` since https://github.com/seattlerb/minitest/commit/00433fc0a4fdd0e6b302aace633384ba13122376
`Minitest::Result` is not test class. So cannot get location directly.

* `assert_header` and `assert_body` were unused since 6f6a589d.
* `assert_success` and `assert_missing` were unused since added.

`invoke_all` cause `bundle install`. This will install gems actually
defined in `Gemfile`. To avoid this, stubbed `bundle_command`.

Fixes #31557

Puma gets bundler's info from `Bundler::ORIGINAL_ENV` for restart.
https://github.com/puma/puma/blob/f6f3892f4d82638fb7a2a57d993641b1486ee88a/lib/puma/launcher.rb#L168

So, specified `BUNDLE_GEMFILE` env for use same Gemfile in the restart.

Fixes #31351

`skip_bundle` option was removed from plugin generator in 9b72fcc3.

This pull request handles `FrozenError` introduced by Ruby 2.5.
Refer https://bugs.ruby-lang.org/projects/ruby-trunk/repository/revisions/61131

Since `FrozenError` is a subclass of `RuntimeError` minitest used by master
branch can handle it, though it would be better to handle `FrozenError`
explicitly if possible.

`FrozenError` does not exist in Ruby 2.4 or lower, `frozen_error_class`
handles which exception is expected to be raised.

This pull request is intended to be merged to master,
then backported to `5-1-stable` to address #31508

Follow up of #31289.

Specifying the `--dev` option is when want to change the codebase,
as it is not necessary to cache it.

Context: https://github.com/rails/rails/pull/31485#issuecomment-352452653

To prevent errors from being raise in environments where credentials
is unnecessary.

Context: https://github.com/rails/rails/issues/31283#issuecomment-348801489

Fixes #31283

Follow up of #31391

`bootsnap` is a useful gem normally. However, `bootsnap` is unnecessary
when generating a Rails application to be used only for testing.
So I want to control whether use this or not by option.

See #31315 for full discussion

Follow up of #31432.

This new ActiveRecord configuration option allows you to easily
pinpoint what line of application code is triggering SQL queries in the
development log by appending below each SQL statement log the line of
Ruby code that triggered it.

It’s useful with N+1 issues, and to locate stray queries.

By default this new option ignores Rails and Ruby code in order to
surface only callers from your application Ruby code or your gems.

It is enabled on newly generated Rails 5.2 applications and can be
enabled on existing Rails applications:

```ruby
Rails.application.configure do
  # ...
  config.active_record.verbose_query_logs = true
end
```

The `rails app:upgrade` task will also add it to
`config/development.rb`.

This feature purposely avoids coupling with
ActiveSupport::BacktraceCleaner since ActiveRecord can be used without
ActiveRecord. This decision can be reverted in the future to allow more
configurable backtraces (the exclusion of gem callers for example).

Follow up of #31390.

Option parsing happens too late to have any impact on the Rails
environment.  Rails accesses the environment name and memoizes it too
early in the boot process for a commandline option to have any impact on
the database connection, so we'll change this test to set the
environment from an environment variable (and ensure it still works when
running tests with `ruby`)

When tests are run with just `ruby`, the RAILS_ENV is set to
`development` too early, and we connect to the development database
rather than the test database.

I frequently run tests with `ruby`, not with a runner like `rake` or
`rails`.  When running the test with just `ruby` the `RAILS_ENV`
environment variable did not get set to "test", and this would cause the
tests to fail (and even mutate the development database!)

This commit adds integration tests for running tests with just `ruby`
and ensures the environment gets defaulted to "test".  I also added a
test to ensure that passing an environment to `-e` actually works (and
fixed that case too).

An interesting / annoying thing is that Minitest picks up it's plugins
by asking RubyGems for a list of files:

  https://github.com/seattlerb/minitest/blob/ca6a71ca901016db09a5ad466b4adea4b52a504a/lib/minitest.rb#L92-L100

This means that RubyGems needs to somehow know about the file before it
can return it to Minitest.  Since we are not packaging Rails as a Gem
before running the integration tests on it (duh, why would you do
that?), RubyGems doesn't know about the file, so it can't tell Minitest,
so Minitest doesn't automatically require it.  This means I had to
manually require and insert the plugin in our integration test.  I've
left comments about that in the test as well.

Ugh.

We probably don't have any tests for the `--webpack` option.
related: #27288