DiffMerge

Diff, merge and browse git history in Neovim, built on Vim's own diff mode. Pure Lua, no dependencies, Neovim 0.12+.

• Status view — Conflicts / Staged / Unstaged / Untracked, like git status. Files open as HEAD | WORKING TREE | INDEX (only the columns that differ); <Space> toggles the line under the cursor between unstaged and staged (lazygit style), - the hunk, visual mode the selection — the change stays in view and changes colour; X discards it. Opened from a file, it shows that file at the cursor's line. The log of the repository goes below it (gL; gF the file panel); g? lists the keys of the window you are in, by function.

• Stashing what you staged — s stashes the staged lines and hunks only (also next to unstaged changes, where git stash --staged fails), files, or everything; stashes are listed below the changes and open like changes, read-only; apply, pop, drop.

• Ignoring — i on a file or directory adds it to .gitignore or .git/info/exclude, by path or by extension (*.log); a tracked file stops being tracked, after a question that says what that means for the repository.

• Committing — cc / ca (amend) in the status view: git's own commit (template, hooks, merge message), the message in a window below, :wq commits, :q! aborts. While a merge, rebase, cherry-pick or revert goes on, cc continues it and c skips / aborts. On a commit of the log: cf fixup with what is staged, cs squash into its parent, cr reword, cd drop; C cherry-pick, X revert, r reset there, T tag.

  

• Fetch / pull / push — F / p / P in the background; pull follows your git config; push offers to set an upstream and, when rejected, --force-with-lease (never --force).

• Branches — b switches (git switch) from a picker of local and remote branches, or to a new one; b on a commit in the log checks it out (its branch, else a branch following a remote one there, detached, or a new branch there); uncommitted changes in the way go along (stash, switch, pop).

• Changed characters are highlighted in merges and in the three columns too (following 'diffopt' inline:), where Vim's own colours would compare every window with every other.

• Any git diff — :DiffMerge diff master...HEAD -- lua/; the view shows the git command.

• Merges, meld-style — git's merge result in the middle (rerere and fixes by hand kept), every conflict shows the base text; resolve with <leader>1 <leader>2 <leader>3 (toggle mine / base / theirs, KDiff3-style), undo just works; <leader>1 / <leader>3 in the file panel take a side for the whole file. Layouts: mine | merged | other (side by side or stacked) and mine | base | other / merged.

  

• Log & history — git log --graph with git's colours, in the status view: its Working tree row is the status, a commit shows what it changed; mark two rows (m m: git diff A B, t: A...B) or select a range (V … <CR>: combined changes); it follows commits, fetches and switches, keeping your place; file, directory and line (-L) history.

  

• git difftool / mergetool — files and --dir-diff directories; proper exit codes.

• Any two files or directories — nvim -c "DiffMerge compare" -- old new (e.g. as a shell alias), both sides editable.

Install

lazy.nvim:

{
  "XobSod/nvim-diffmerge",
  cmd = "DiffMerge",
  opts = {},
  keys = {
    { "<leader>do", "<CMD>DiffMerge<CR>", desc = "Status" },
    { "<leader>dl", "<CMD>DiffMerge log<CR>", desc = "Log (show / hide)" },
    { "<leader>df", "<CMD>DiffMerge files<CR>", desc = "Files (show / hide)" },
    { "<leader>dh", "<CMD>DiffMerge history<CR>", desc = "History (file)" },
    { "<leader>dh", ":DiffMerge history<CR>", mode = "x", desc = "History (lines)" },
    { "<leader>dc", "<CMD>DiffMerge conflicts<CR>", desc = "Conflicts" },
    { "<leader>dq", "<CMD>DiffMerge close<CR>", desc = "Close" },
  },
}

git integration

[diff]
  tool = diffmerge
[difftool]
  prompt = false
[difftool "diffmerge"]
  cmd = nvim -c \"DiffMerge difftool\" -- \"$LOCAL\" \"$REMOTE\" \"$MERGED\"
[merge]
  tool = diffmerge
[mergetool "diffmerge"]
  cmd = nvim -c \"DiffMerge mergetool\" -- \"$LOCAL\" \"$BASE\" \"$REMOTE\" \"$MERGED\"
  trustExitCode = true
[alias]
  mt = !nvim -c \"DiffMerge conflicts\"

git mergetool gets exit code 0 only when every conflict is resolved and saved; otherwise git restores the file and reports the merge as failed. git mt resolves all conflicts in one Neovim.

Documentation

:help diffmerge — commands, views, keymaps (g? in any view), configuration, highlights.

DESIGN.md — how DiffMerge is meant to behave, and why.

Compatibility

Breadcrumb plugins (winbar)

DiffMerge labels every side in the window bar (WORKING TREE, INDEX, LOCAL · ours · master, …). Breadcrumb plugins that write the winbar of any window with an LSP client can overwrite the label of working-tree files. lspsaga means to leave diff windows alone but only checks when it attaches to a buffer; this makes it check every time it draws:

-- after require("lspsaga").setup(opts)
local crumbs = require("lspsaga").config.symbol_in_winbar
local enabled = crumbs.enable
crumbs.enable = nil
setmetatable(crumbs, {
  __index = function(_, key)
    if key == "enable" then
      return enabled and not vim.wo.diff -- no breadcrumbs in diff windows
    end
  end,
})

Tests

./tests/run.sh                  # all specs, headless, against throwaway repositories
./tests/run.sh tests/merge_spec.lua

The GIFs above are recorded with VHS from demo/tapes/ and made smaller with gifsicle, in Docker (everything included; no config of yours):

./demo/render.sh                  # every GIF
./demo/render.sh merge log        # demo/tapes/merge.tape, demo/tapes/log.tape

License

MIT, see LICENSE.