Simple bash script to generate a changelog based on tags & commit messages

git-changelog

#!/usr/bin/env bash

function printCommitLine(){
  local FROM=$1
  local TO=$2
  if [ TO ]; then
    git log $GIT_LOG_OPTS --format="$LOG_FORMAT_OPTS" $FROM..$TO
  else
    git log $GIT_LOG_OPTS --format="$LOG_FORMAT_OPTS" $FROM
  fi
}

function printTitleLine(){
  local TAG=$1
  printf "\n"
  echo "## [$TAG]($TAG_URL$TAG)"
}

if [ -e 'bower.json' ]; then
  MANIFEST='bower.json'
elif [ -e 'package.json' ]; then
  MANIFEST='package.json'
else
  echo "Can't find package.json or bower.json"
  exit 1
fi

NAME=$(node -p "require('$MANIFEST').name")
TAG_URL="https://cgit.twitter.biz/$NAME/tag/?id="
COMMIT_URL="https://cgit.twitter.biz/$NAME/commit/?id=%h"
GIT_LOG_OPTS="--no-merges"
LOG_FORMAT_OPTS=" * [%h]($COMMIT_URL) %s"
TAGS=$(git tags | grep '^\d\.\d\.\d' | sort -u -r)
PREV='HEAD'
FIRST=$(git rev-list --max-parents=0 HEAD)
for CTAG in ${TAGS[@]}; do
  printTitleLine $PREV
  printCommitLine $CTAG $PREV
  PREV=$CTAG
done

printTitleLine $CTAG
printCommitLine $FIRST $CTAG