I'm having a hard time imagining the alternative. Do junior developers not take any pride in their work? I want to be sure my code works before I submit it for review. It's embarrassing to me if it fails basic requirements. And as a reviewer, what I want to see more than anything is how the developer assessed that their code works. I don't want to dig into the code unless I need to -- show me the validation and results, and convince me why I should approve it.
I've seen plenty of examples of developers who don't know how to effectively validate their work, or document the validation. But that's different than no validation effort at all.