What is the Purpose of Creation and Testing in Islam?

Why did Allah create us and put us through tests? Did Allah create everything out of boredom or for amusement? Our main purpose is to worship Allah, but why did He design this testing process? Instead of testing us, couldn't Allah have placed us directly in Jannah without any trials? Why is there a specific criteria for entering Jannah? These questions arise when pondering the purpose of creation and the testing we undergo. *Just to clarify, I know that our purpose of life is to worship Allah, but what is the purpose of God Creating us, He could have still been God without us.