Hi
I see that extensions.php is used to inialize \yii:$app->extensions which will run bootstrap functionality of that extensions.
Is there another function for \yii:$app->extensions ?
And I do not understand how extensions.php file is created.
At what stage?
Could I make some changes to this file by myself?
The file is generated by composer when installing packages of type "yii2-extension". Its content is generated from the autoload specs of the packages composer.json and also from the extra part of composer.json.
See also:
http://stuff.cebe.cc/yii2docs/guide-extend-creating-extensions.html#bootstrap-with-extension