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.

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

This is necessary in order to make the processing dependent on
`Migrator.current_version` work even without database.

Context: https://github.com/rails/rails/pull/31135#issuecomment-348404326

With the current code, a failing test shows this error, which is missing
the number of times called and has two periods at the end.

```
/railties$ be ruby -Itest test/generators/app_generator_test.rb -n test_active_storage_install

Failure:
AppGeneratorTest#test_active_storage_install [test/generators/app_generator_test.rb:313]:
active_storage:install expected to be called once, but was called  times..
Expected: 1
  Actual: 2
```

After the fix, the error message looks correct:

```
/railties$ be ruby -Itest test/generators/app_generator_test.rb -n test_active_storage_install

Failure:
AppGeneratorTest#test_active_storage_install [test/generators/app_generator_test.rb:313]:
active_storage:install expected to be called once, but was called 2 times.
Expected: 1
  Actual: 2
```

Fixes #31286

Follow up of 924a368f

Since `ContentSecurityPolicy::Middleware` is not loaded in API-only
Applications, initializer is unnecessary.
Ref: https://github.com/rails/rails/blob/9c10fec4c06da38f8975dfb851f4d899aa85f8b7/railties/lib/rails/application/default_middleware_stack.rb#L66..L68

- Followup of #31162

https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy

In order to use early hints, need to use Puma 3.11.0 or higher.
So, I think that should specify that version in newly generated applications.

Ref: https://github.com/puma/puma/commit/f6f3892f4d82638fb7a2a57d993641b1486ee88a

This was added with 27f103fc for link labels and fields.
However, `form_with` changed to generates ids by default with d3893ec3.
So I think that adding an explicit ids is unnecessary.

When `form_with` was introduced we disabled the automatic
generation of ids that was enabled in `form_for`. This usually
is not an good idea since labels don't work when the input
doesn't have an id and it made harder to test with Capybara.

You can still disable the automatic generation of ids setting
`config.action_view.form_with_generates_ids` to `false.`

Since fbd1e98c, Rails plugin does not
run `bundle install` when generating.
Therefore, `after_bundle` callback is not actually executed after `bundle`.

Since there is a difference between the name and the actual behavior,
I think that should be remove.

We generate master key on `rails new`.
Therefore, if do not add master key to `.gitginore` on `rails new`as
well, there is a possibility that the master key will be committed
accidentally.

To edit/show encrypted file:

```
bin/rails encrypted:edit config/staging_tokens.yml.enc
bin/rails encrypted:edit config/staging_tokens.yml.enc --key config/staging.key
bin/rails encrypted:show config/staging_tokens.yml.enc
```

Also provides a backing Rails.application.encrypted API for Ruby access:

```ruby
Rails.application.encrypted("config/staging_tokens.yml.enc").read
Rails.application.encrypted("config/staging_tokens.yml.enc").config
Rails.application.encrypted("config/staging_tokens.yml.enc", key: "config/staging.key")
```

Ensure plugin_generator adds to new line in Gemfile, even if the Gemfile
does not end with an empty line.

[Lisa Ugray, Nikita Penzin]

Currently the environment is not loaded in some db tasks.
Therefore, if use encrypted secrets values in `database.yml`,
`read_encrypted_secrets` will not be true, so the value can not be
used correctly.

To fix this, added `environment` as dependency of `load_config`.
It also removes explicit `environment` dependencies that are no longer
needed.

Fixes #30717

Make clear that the files are not to be run for interpreters.

Fixes #23847.
Fixes #30690.
Closes #23878.

Allow edits of existing encrypted secrets generated on Rails 5.1,
but refer to credentials when attempting to setup.

This also removes the need for any of the setup code, so the
generator can be ripped out altogether.

Since credentials generator is executed via the credentials command and
does not need to be executed directly, so it is not necessary to show it in
help.

These were added in #30101, after #31084 it became redundant.

Since isolation application is generated with the `--skip-gemfile`
option, so `active_storage:install` is not executed.

In order to execute the `rails` command, need to run bundle install in
advance.
Therefore, if skipped bundle install, `rails` command may fail and
should not do it.

Ensure that `bin/rails db:migrate` with specified `VERSION` reverts
all migrations only if `VERSION` is `0`.
Raise error if target migration doesn't exist.

Omit `rails activestorage:install` for jdbcmysql, jdbc and shebang tests

AppGeneratorTest#test_config_jdbcmysql_database

  rails aborted!
  LoadError: Could not load 'active_record/connection_adapters/mysql_adapter'.
  Make sure that the adapter in config/database.yml is valid.
  If you use an adapter other than 'mysql2', 'postgresql' or 'sqlite3' add
  the necessary adapter gem to the Gemfile.
  (compressed)
  bin/rails:4:in `<main>'
  Tasks: TOP => activestorage:install => environment
  (See full trace by running task with --trace)

AppGeneratorTest#test_config_jdbc_database

  rails aborted!
  LoadError: Could not load 'active_record/connection_adapters/jdbc_adapter'.
  Make sure that the adapter in config/database.yml is valid.
  If you use an adapter other than 'mysql2', 'postgresql' or 'sqlite3' add
  the necessary adapter gem to the Gemfile.
  (compressed)
  bin/rails:4:in `<main>'
  Tasks: TOP => activestorage:install => environment
  (See full trace by running task with --trace)

AppGeneratorTest#test_shebang_is_added_to_rails_file

  /home/ubuntu/.rbenv/versions/2.4.1/bin/ruby: no Ruby script found in input (LoadError)

Prevent PendingMigrationError in tests

 * Run `bin/rails db:migrate RAILS_ENV=test` in test_cases before start tests to prevent PendingMigrationError
 * FileUtils.rm_r("db/migrate")
 * --skip-active-storage

Fix failed tests in `railties/test/railties/engine_test.rb`

Related to #30111

Imporve `SharedGeneratorTests#test_default_frameworks_are_required_when_others_are_removed`

 - Explicitly skip active_storage
 - Ensure that skipped frameworks are commented
 - Ensure that default frameworks are not commented

Fix error `Errno::ENOSPC: No space left on device - sendfile`

Since `rails new` runs `rails active_storage:install`
that boots an app.

Since adding Bootsnap 0312a5c6
during booting an app, it creates the cache:

   264K    tmp/cache/bootsnap-load-path-cache
   27M     tmp/cache/bootsnap-compile-cache

* teardown_app must remove app

Closes #30102

Revert part 787fe90d

--skip-active-storage pass throughs `rails plugin new`

Add changelog entry about default initialization of Active Storage

Currently, namespaced scaffold generator will generate an incorrect path
and the generated file will not work properly.

```
$ ./bin/rails g scaffold admin/user
$ ./bin/rails db:migrate
$  ./bin/rails t test/controllers
# Running:

E

Error:
Admin::UsersControllerTest#test_should_create_admin_user:
NameError: undefined local variable or method `admin_admin_users_url' for #<Admin::UsersControllerTest:0x000055a59f25ff68>
Did you mean?  admin_users
    test/controllers/admin/users_controller_test.rb:20:in `block (2 levels) in <class:UsersControllerTest>'
    test/controllers/admin/users_controller_test.rb:19:in `block in <class:UsersControllerTest>'

bin/rails test test/controllers/admin/users_controller_test.rb:18
```

This is because combine `controller_class_path` and `singular_table_name`
to generate route.
https://github.com/rails/rails/blob/360698aa245b45349d1d1b12e1afb34759515e69/railties/lib/rails/generators/named_base.rb#L172

Normally, if using namspaced generator, table name already contains
namespace. Therefore, adding `controller_class_path` adds extra namespace.
Since it is special only when explicitly specifying `model-name`, it is
modified to change the value only when `model-name`is specified.

Follow up of #30729