Emacs is the best merge tool for Git

Insert below code into ~/.gitconfig ,

[mergetool.ediff]
# use git mergetool ediff to resolve conflicts
cmd = emacs -nw -Q --eval \"(setq startup-now t)\" -l \"~/.emacs.d/init.el\" --eval \"(progn (setq ediff-quit-hook 'kill-emacs) (if (file-readable-p \\\"$BASE\\\") (ediff-merge-files-with-ancestor \\\"$LOCAL\\\" \\\"$REMOTE\\\" \\\"$BASE\\\" nil \\\"$MERGED\\\") (ediff-merge-files \\\"$LOCAL\\\" \\\"$REMOTE\\\" nil \\\"$MERGED\\\")))\"

In above code, option -Q equals -q --no-site-file --no-splash . Actually, only -q is critical. -q means "Do not load an init file". A global emacs lisp flag startup-now is defined before loading ~/.emacs.d/init.el .

Then in ~/.emacs.d/init.el , I need only add one line,

(when (not (boundp 'startup-now))
  ;; heavy weight configuration happens here
  )

When startup-now is defined, all the heavyweight configuration should be off. Considering in this scenario, we are using Emacs only as merge tool, 99% configuration could be turned off. For example, set up for any programming language is not required. Flyspell and flycheck should be off. Yasnippet is also useless.

I only need focus on essential operations related to text/file/window.

Evil should be used. At the beginning of this article, I said "I love vimdiff because it's fast". It's impossible to be more efficient without Evil.

Any patch/diff utilities should be included too. counsel/swiper/ivy is also must have because I can use counsel-git to find file and counsel-git-grep to grep text.

Native Emacs API is enough to save/load windows layout.