Comment by a_t48
4 hours ago
The PRs may be orthogonal but still be dependent. Feature X depends on improvement Y which also needs bugfix Z. You might go and implement X in a branch, tweaking the codebase as you go, but split the branch apart for review. You put X/Y/Z up, but X contains Y and Z, which means you can't request reviews for X without Y and Z merging, or else have a bunch of extra code that gets in the way.
Let's say that Z has an error (some assumption that does not hold), and needed to be reverted. How does that impact X's viability? I wouldn't trust any reviews of X after that.
I strongly believe that PR should be compared to the main branch, and not rely on unmerged code. Unless you merge everything together in one go. And in the latter case, everything should be reviewed together.
I think the answer is - it depends! This is why we make good money. I don’t think there’s a hard and fast rule here to apply.
If the tooling allows rollbacking X, Y and Z as a set, it could make sense ?
I'm also on the "compare to the main branch" camp in general, but will sometimes end up with a set of X,Y,Z branches that have different purposes but all depend on X.
More often than not, the base dependency is a set of constants or additional class/methods that could be released with no impact (no reference in live code) but still need a somewhat lenghty review process. Reverts would be happening on the higher level PRs, which hopefully are independent.