pre-commit

#!/usr/bin/env bash
# This is a pre-commit hook that validates code formatting.
#
# Install this by running the script with an argument of "install",
# which adds a symlink at .git/hooks/precommit; or run the equivalent:
#
# $ ln -s ../../hooks/pre-commit .git/pre-commit

root="$(git rev-parse --show-toplevel 2>/dev/null)"
venv="$root/venv"
pip="$venv/bin/pip"
python="$venv/bin/python"

# Some sanity checking.
hash python3 || exit 1
[[ -n "$root" ]] || exit 1

# Installation.
if [[ "$1" == "install" ]]; then
    hook="$root"/.git/hooks/pre-commit
    if [[ -e "$hook" ]]; then
        echo "Hook already installed:"
        ls -l "$hook"
    else
        ln -s ../../pre-commit "$hook"
        echo "Installed git pre-commit hook at $hook"
    fi
    exit
fi

# venv setup
if [ ! -d "$venv" ]; then
    echo "Setting up python venv"
    python3 -m venv "$venv"
fi

source "$venv/bin/activate"

if [ requirements.txt -nt "$venv" ]; then
    "$pip" install --upgrade --upgrade-strategy eager -r requirements.txt
fi

exec 1>&2

# Perform validation.
trap 'git stash pop -q' EXIT
git stash push -k -u -q -m "pre-commit stash from $(date '+%FT%T%z')"
if ! "$python" activities.py validate; then
    echo "Validation failed; \`git commit --no-verify\` to suppress validation."
    exit 1
fi