If you do option while moving the file it merges both directories but even I didn't know this until I googled it.
If you copy-paste a folder using the keyboard, a dialog pops up asking you whether to merge the contents. Totally inconsistent with drag-and—drop, but useful to know.
alt Hacker News
If you copy-paste a folder using the keyboard, a dialog pops up asking you whether to merge the contents. Totally inconsistent with drag-and—drop, but useful to know.