These guidelines drawn from:

https://www.atlassian.com/blog/git/written-unwritten-guide-pull-requests

https://github.com/blog/1943-how-to-write-the-perfect-pull-request

https://github.com/thoughtbot/guides/tree/master/code-review

How To Review a Pull Request (PR)

So you’ve been assigned to review another developer’s code. What do you need to do?