jos/.hooks/commit-msg

#!/usr/bin/env bash

# This hook checks if the commit message ends with an issue number, and if not,
# tries to derive that number from the branch name

branch=`git rev-parse --abbrev-ref HEAD`
issue_num=`echo "$branch" | grep -Po '^[0-9]+(?=-)'`

# Check if issue number is already present
if ! grep -q '([0-9]\+)$' "$1"; then
    # Error out if we can't derive issue number
    [[ -z "$issue_num" ]] && { 
        >&2 echo "Couldn't derive issue number from branch. Please add one manually.";
        exit 1;
    }

    # Append issue number, and remove all comments
    echo "[#$issue_num]" "$(cat "$1")" > "$1"
fi