Diff files using neoVim

1. The vimdiff Command (for files)

If you're starting Neovim fresh and want to compare two files, this is your go-to:

nvim -d file1.txt file2.txt

This will launch Neovim with both files open in a split window, and it'll highlight all the juicy differences.

2. The :diffthis Command (for open buffers)

Now, this is where it gets really fun and flexible, especially if you already have files or even unsaved text in buffers:

Scenario A: You have two buffers open in separate splits.

1. Make sure you have two buffers open in separate windows (e.g., using :split or :vsplit).
2. Go to the first window and type:

   :diffthis
   

3. Switch to the second window (e.g., Ctrl-w w or Ctrl-w h/l/j/k) and type:

   :diffthis
   

Voila! Neovim will automatically show you the differences between those two buffers. It's like magic, but better, it's code!

Scenario B: You have two buffers, and you want to quickly set up the split.

Let's say you have buffer_A and buffer_B that you want to compare.

1. Open one of them (or just be in it):

   :e buffer_A
   

2. Then open the second one in a vertical split for a side-by-side view (my personal fave!):

   :vsplit buffer_B
   

3. Now, in both windows, you can apply :diffthis as in Scenario A, or even better, if they're the only two windows, use:

   :windo diffthis
   

   This command applies diffthis to all windows in your current tab. So efficient!

Getting Around in Diff Mode & Other Goodies:

Once you're in diff mode, you'll love these shortcuts:

• [c: Jump to the previous change.
• ]c: Jump to the next change.
• do (diffget, in one buffer): Pulls changes from the other buffer into the current one. Use this when you want to accept a change from the other side.
• dp (diffput, in one buffer): Pushes changes from the current buffer into the other one. Use this when you want to apply your changes to the other side.
• :diffupdate: If you've made more changes, use this to refresh the diff highlighting.
• :diffoff: To turn off diff mode for the current window.
• :windo diffoff: To turn off diff mode for all windows in the current tab.

Neovim's diffing capabilities are seriously powerful and so handy for comparing code, notes, or anything else you're working on.