Jujutsu does not treat merge commits any more or less special than non-merge "1-parent" commits. (We used to do this, actually, and occasionally special case merges, but most users found it very confusing.) This regularity means most commands work fine on merges. 'jj new X' is a new commit on top of X. 'jj new X Y' is a merge commit with X and Y as parents. 'jj new X Y Z...' is a 3-way merge, and so on and so forth for any number of commits. Similarly, 'jj rebase' can handle moving commits and preserving the graph structure no matter how many edges are involved in particular, and can add or remove parents from a given commit. This means that conceptually the jj commit graph is merely a simple, ordinary DAG, and operations are transformations on the DAG like you expect.
Actually, this exact workflow is beloved by many community members, and I guess I can take responsibility for popularizing it originally, the "Mega Merge" technique. Instant, easy rebase is an essential part of making this technique viable.
- https://ofcr.se/jujutsu-merge-workflow - https://v5.chriskrycho.com/journal/jujutsu-megamerges-and-jj...