Gitconfig - colored and highlighted diff

.gitconfig

[user]
	email = [email protected]
	name = Alessandro Menduni
[alias]
	diff = diff --color --color-words --abbrev
[core]
	pager = bash -lc 'diff-highlight | diff-so-fancy | less -r' -
[color "diff"]
	meta = yellow bold
	commit = green bold
	frag = magenta bold
	old = red bold
	new = green bold
	whitespace = red reverse

diff-so-fancy

#!/bin/bash

###############
# Details
#
# Screenshot: https://github.com/paulirish/dotfiles/commit/6743b907ff58#commitcomment-13349456
# Simplified diff header format
# No `+` or `-` at the beginning of each line, to make for easier copypaste action.
###############


###############
# Usage
#
#   git diff | diff-highlight | diff-so-fancy
#
# Add to .gitconfig so all `git diff` uses it.
#   git config --global core.pager "bash -lc 'diff-highlight | diff-so-fancy | less -r'
###############


###############
# Requirements / Install
#
# * GNU sed. On Mac, install it with Homebrew:
#   	brew install gnu-sed --default-names  # You'll have to change below to `gsed` otherwise
# * diff-highlight. It's shipped with Git, but probably not in your $PATH
#       ln -sf "$(brew --prefix)/share/git-core/contrib/diff-highlight/diff-highlight" ~/bin/diff-highlight
# * Add to your .gitconfig:
#       [color "diff-highlight"]
#       	oldNormal = "red bold"
#       	oldHighlight = "red bold 52"
#       	newNormal = "green bold"
#       	newHighlight = "green bold 22"
#
###############

# TODO:
#   Put on NPM.


[ $# -ge 1 -a -f "$1" ] && input="$1" || input="-"

color_code_regex=$'(\x1B\\[([0-9]{1,2}(;[0-9]{1,2})?)[m|K])?'
reset_color="\x1B\[m"
dim_magenta="\x1B\[38;05;146m"

format_diff_header () {
	# simplify the unified patch diff header
	sed -E "s/^($color_code_regex)diff --git .*$//g" | \
	sed -E "s/^($color_code_regex)index .*$/\
\1$(print_horizontal_rule)/g" | \
	sed -E "s/^($color_code_regex)\+\+\+(.*)$/\1\+\+\+\5\\
\1$(print_horizontal_rule)/g"
}

colorize_context_line () {
	# extra color for @@ context line
	sed -r "s/@@$reset_color $reset_color(.*$)/@@ $dim_magenta\1/g"
}

strip_leading_symbols () {
	# strip the + and -
	sed -r "s/^($color_code_regex)[\+\-]/\1 /g"
}

print_horizontal_rule () {
		printf "%$(tput cols)s\n"|tr " " "-"
}

# run it.
cat $input | format_diff_header |  colorize_context_line | strip_leading_symbols