LazyVim/Q/What is the easiest workflow to look up a file and diff it against another branch?

• What is the easiest workflow to look up a file and diff it against another branch?

  • AI Answer

    • Short answer: Find the file with <leader>ff (or <leader><space>), then run :Gitsigns diffthis <branch> for a side-by-side vimdiff of the open buffer against that branch's version of the same path. That is the shortest stock LazyVim path that stays in the editor and targets one file.

    • Recommended workflow

      • 1. <leader>ff (or <leader><space>) — fuzzy file picker at the project root; open the file. Same picker as on LazyVim/Keyshort/Search.
      • 2. :Gitsigns diffthis main — replace main with any ref (origin/main, a feature branch, a SHA). Opens a vertical vimdiff: left is the revision, right is the working-tree buffer. Close the revision window with :q when done.
      • 3. Navigate hunks with ]h / [h while the diff is open (same keys as the nvim/Plugin/gitsigns.nvim hunk maps LazyVim binds under <leader>gh).

    • Why this wins for "one file vs another branch"

      • LazyVim already ships nvim/Plugin/gitsigns.nvim. Its stock maps cover <leader>ghd (diff vs index) and <leader>ghD (diff vs ~), but not an arbitrary branch — so the Ex form :Gitsigns diffthis <branch> is the intended escape hatch. Answer/Official from gitsigns :Gitsigns diffthis and LazyVim's gitsigns on_attach.
      • It scopes to the current buffer automatically. No path typing after the file is open, and no whole-tree picker to filter down.

    • Good alternatives in the same stack

      • PR-style, many files, filter to one: <leader>gD opens nvim/Plugin/snacks.nvim's git_diff against the merge-base with origin (group = true). Type part of the path in the picker to narrow to one file. For a named base instead of origin: :lua Snacks.picker.git_diff({ base = "main", group = true }). This answers "what changed on this branch since it diverged," which is merge-base semantics, not always tip-to-tip. Answer/Official from LazyVim snacks picker keymaps and snacks git_diff base.
      • Branch-to-branch in Lazygit: <leader>gg → Local Branches → cursor on the other branch → W (diffing options) → select / enter the other ref → land in the diff files view → / to filter by path. Best when the question is "everything this branch changed," then drill into one file. Answer/Official from lazygit keybindings — View diffing options.
      • Patch in a pager, no split: with the file open, :!git diff <branch> -- % or a floating terminal via <leader>ft and the same command. Fastest for a quick read; worse for navigating hunks side by side.
      • Historical contents only (not a diff): git show <branch>:<path> — see git/show.

    • What not to reach for first

      • diffview.nvim (:DiffviewOpen main -- %) is excellent for this job, but it is not stock LazyVim — enable it only if it is already installed.
      • Opening Lazygit with --filter on the current file (as in Lazygit/Q/Can an agent open lazygit on one file in one commit for me to review?) is great for commit history of one path; it does not by itself start a compare against another branch tip.