azure-cli-extensions: add commit helper script

#!/usr/bin/env bash

# Just a tiny imperfect helper script to commit generated updates.

#

# First, ensure that that `git add -p extensions-generated.nix` only

# returns a series of clean update hunks, where each hunk updates a

# single package version. All additions/removals must be committed

# by hand.

# The script will then commit the remaining hunks with fitting commit messages.

while true; do

  echo -e "y\nq" | git add -p extensions-generated.nix || break

  pname=$(git diff --no-ext-diff --cached | grep "pname =" | cut -d'"' -f2 | head -n1) || break

  versions=$(git diff --no-ext-diff --cached | grep "version =" | cut -d'"' -f2) || break

  oldver=$(echo "$versions" | head -n1) || break

  newver=$(echo "$versions" | tail -n1) || break

  commitmsg="azure-cli-extensions.${pname}: ${oldver} -> ${newver}"

  git commit -m "$commitmsg"

done