githelpers

#!/bin/bash

# All credit to Gary Bernhardt for this.

# Log output:
#
# * 51c333e    (12 days)    <Gary Bernhardt>   add vim-eunuch
#
# The time massaging regexes start with ^[^<]* because that ensures that they
# only operate before the first "<". That "<" will be the beginning of the
# author name, ensuring that we don't destroy anything in the commit message
# that looks like time.
#
# The log format uses } characters between each field, and `column` is later
# used to split on them. A } in the commit subject or any other field will
# break this.

HASH="%C(yellow)%h%Creset"
RELATIVE_TIME="%Cgreen(%ar)%Creset"
AUTHOR="%C(bold blue)<%an>%Creset"
REFS="%C(red)%d%Creset"
SUBJECT="%s"

FORMAT="$HASH}$RELATIVE_TIME}$AUTHOR}$REFS $SUBJECT"


show_git_head() {
    pretty_git_log -1
    git show -p --pretty="tformat:"
}


pretty_git_log() {
    WIDTH=$(tput cols)
    git log --color=always --graph --pretty="tformat:${FORMAT}" $* |
        # Replace (2 years ago) with (2 years)
        sed -Ee 's/(^[^<]*) ago\)/\1)/' |
        # Replace (2 years, 5 months) with (2 years)
        sed -Ee 's/(^[^<]*), [[:digit:]]+ .*months?\)/\1)/' |
        # Line columns up based on } delimiter
        column -s '}' -t |
        # Page only if we need to
        less -FXRS
}


# And now I add my own git helper shell functions:
git_checkpoint() {
    git add --all
    git commit --message "wip: $(uuidgen)"
}


histogram() {
    # This takes <int> <value> rows and gives <value> <histo>
    perl -lane 'print $F[1], "\t", "=" x ($F[0] / 5)'
}


# From Ally PIechowski
# https://piechowski.io/post/git-commands-before-reading-code/
git_most_changes() {
    git log --format=format: --name-only --since="1 year ago" \
        | grep -v '^$' \
        | sort \
        | uniq -c \
        | sort -nr \
        | head -20
}

git_who_made_this() {
    git shortlog -sn --no-merges
}

git_bug_clusters() {
    git log -i -E --grep="fix|bug|broken" --name-only --format='' \
        | sort \
        | uniq -c \
        | sort -nr \
        | head -20
}

git_commit_frequencies() {
    git log --format='%ad' --date=format:'%Y-%m' \
        | sort \
        | uniq -c
}

git_firefighting_metric() {
    git log --oneline --since="1 year ago" \
        | grep -iE 'revert|hotfix|emergency|rollback'
}