Conflict Resolution in a Bidirectional Sync App — How I Handle the Hard Cases (opens in new tab)

All tests run on an 8-year-old MacBook Air. All results from shipping 7 Mac apps as a solo developer. No sponsored opinion. HiyokoAutoSync does bidirectional sync between Android and Mac. Bidirectional sync has a hard problem: what happens when the same file is modified on both sides? Here's how I handle it. The conflict cases File modified on both sides since last sync — which version wins? File deleted on one side, modified on the other — delete or keep? File moved on one side — move on the...