How to test a merge without actually merging first

Question

Is there any way of simulating a git merge between two branches, the current working branch and the master, but without making any changes?

I often have

Answer 1

I don't know exactly if it is your case, but your question remember me that sometimes I start a feature, I commit over the days and I merge the develop on it many times.

On this point I lose the control over the exact files I changed and I will only know it when my feature were closed and my code go to develop.

In this case, a good way to know what modifications you did (not other from the merges) is using Sourcetree.

You must click with the right button on the base branch and select Diff Against Current:

Then sourcetree will show you all the modifications that will be merged if you merge your branch into base branch.

Of course, it will not show you the conflicts, but it is a useful tool in merges.