Fix logger for case Yii::$app lost on process exiting

[tanakahisateru]

Logger::flush() might be called by register_shutdown_function() when application instance has gone.

In fact, Codeception extension clears Yii::$app on every test cases.

yii2/extensions/codeception/TestCase.php

Line 129 in c9d51ee

Yii::$app = null;

[cebe]

Why do you have the logger configured in your Tests? Should be skipped IMO because it will result in n shutdown functions to be registered for n tests...

[tanakahisateru]

Which does "Tests" point (a) my own app's tests using Codeception or (b) test added while this PR?

(a) I'm using single logger instance stored in 'Yii::$_logger' commonly.
(b) There are 3 new Logger in other tests. Already 3 shutdown function are registered before my modification. (I think that it's better if they are shared)

My problem is that actually PHP crashed at the end of codecept run.

FAILURES!
Tests: 4, Assertions: 11, Failures: 2.
PHP Fatal error:  Call to a member function getRequest() on null in /.../vendor/yiisoft/yii2/log/Target.php on line 269
PHP Stack trace:
PHP   1. {main}() /.../vendor/codeception/codeception/codecept:0
PHP   2. Symfony\Component\Console\Application->run() /.../vendor/codeception/codeception/codecept:27
PHP   3. yii\log\Logger->flush() /.../vendor/yiisoft/yii2/log/Logger.php:0
PHP   4. yii\log\Dispatcher->dispatch() /.../vendor/yiisoft/yii2/log/Logger.php:170
PHP   5. yii\log\Target->collect() /.../vendor/yiisoft/yii2/log/Dispatcher.php:183
PHP   6. yii\log\FileTarget->export() /.../vendor/yiisoft/yii2/log/Target.php:111
PHP   7. array_map() /.../vendor/yiisoft/yii2/log/FileTarget.php:99
PHP   8. yii\log\Target->formatMessage() /.../vendor/yiisoft/yii2/log/FileTarget.php:99
PHP   9. yii\log\Target->getMessagePrefix() /.../vendor/yiisoft/yii2/log/Target.php:250

My app has no special config.

[
    'components' => [
        'log' => [
            'traceLevel' => YII_DEBUG ? 3 : 0,
            'targets' => [
                [
                    'class' => 'yii\log\FileTarget',
                    'levels' => ['error', 'warning'],
                ],
            ],
        ],

Perhaps some of my functions called Yii::error() or Yii::warning() then the test runner terminated while those messages are remaining in the buffer.

[tanakahisateru]

Similar result would be displayed by below code.

Yii::error("test");
Yii::$app = null;
exit;

[Ragazzo]

@cebe to be true i already faced with 2 - 5 such examples here in issues about testing you can search it if needed )

[cebe]

I am asking why you need to enable the log dispatcher in the test application? If you create a new instance for each test case you will spam the logfiles which you do not need and it will also make your tests slower. To avoid this problem, just do not configure a log component in application.

In normal envirnoment there is no reason to unset Yii::$app and it is not only the logger that relies on an application instance being available in Yii::$app.

[cebe]

related to #6102

[Ragazzo]

I am asking why you need to enable the log dispatcher in the test application?

It is the problem that developers dont throw exceptions (fail fast , let it fail) and only use Yii::log and so on , in their applications everywhere . That is the reason as you can see )

[cebe]

but are you using these logs when running tests to determine the state of the tests or evaluate them?
I do not see any value in this when each test has its own log router with default config...

[Ragazzo]

i dont use this logs , i just throw an exception if something goes not according contracts )

[cebe]

yeah, this questions was more directed to the issue starter :)
so, @tanakahisateru can you please explain why you need this (#6549 (comment))?

[tanakahisateru]

@cebe Because current both application template basic and advanced are reusing app config and do not redefine log dispatcher for tests.
Though any logs are not useful while running tests. But it's a different issue from such as null pointer exception, I think.
Not for only tests, null check is better practice against unexpected situation.

[klimov-paul]

It is already resolved by b338240