How do I show the diff in a single window in fugitive.vim?

Question

Best I can tell, all the diff commands in Fugitive open up a split window. Is there a way to just show the added/deleted/modified lines in a single window -- i.e., show the current file's changes (since the last commit, or, ideally, since an arbitrary commit) without opening a window with the index version?

Answer 1

If the unified/inline diff is what you mean by a single window, you can use Fugitive :Git diff @ -- % command to just show the added/deleted/modified lines of the current file since the last commit in a new single window.

If you are looking for intra-line diff, as the opposite of side-by-side diff, just like VSCode's inline diff view Example (set diffEditor.renderSideBySide option to false) or GitHub's Unified diff display Example ... Unfortunately, Vim doesn't support that.

If you only want to show the changes since the last commit, just run :G command, here is the unified diff format. Otherwise, you can use git's diff command by Fugitive, just run :G diff BASE_COMMIT to show the unified/inline diff against an arbitrary commit. For example, :G diff HEAD, :G diff @~2 -- %, :G diff f88a3b8 and so on. For details to see git docs (git diff --help) and fugitive docs (:help fugitive, :h fugitive-object).

Is there a way to just show the added/deleted/modified lines in a single window ?

Solution other than fugitive: If you only want to show the unified/inline diff highlighting just in the current window, maybe you need other plugins see IDE-like inline diff highlighting in Vim. About the vim-gitgutter plugin, as for your question, jump to the doc of vimdiff. You can also specify an arbitrary commit to compare against by the g:gitgutter_diff_base variable (e.g. :let g:gitgutter_diff_base = 'HEAD~2'). Then you can run :GitGutterFold command to see the current file's changes without opening any other windows. Now you can use :GitGutterPrevHunk and :GitGutterNextHunk to jump between your change hunks, and :GitGutterPreviewHunk to show the hunk details. Of course, there is also a :GitGutterDiffOrig command here, just like the Fugitive :Gdiffsplit command. For convenience, see :help gitgutter-mappings. For more features and details see it's documentations, it will be helpful to use it with vim-fugitive.