Notes and References
We can use git merge --no-commit to prevent the merge from actually being committed, and if we don’t like how the merge works out, just reset to the original head. If you definitely don’t want to finalize the merge, even if it’s a fast-forward (and thus has no conflicts, by definition), you could add --no-ff as well.
git config --global alias.merge-test '!f() { git merge --no-commit --no-ff "$@"; echo "Run \"git merge --abort\" if you don'\''t want to commit the changes"; }; f'To be more safe, we can do the following:
git checkout main
git checkout -b test-merge
git merge topic-branch
After completing the merge, it is easy to see the consolidated change from main
git diff main
When done, simply delete the test-merge branch
git checkout main
git branch -D test-merge
This way, the main branch never changes.
Stack Overflow Question - How to test a merge without actually merging first