changelog

#!/bin/bash
SINCE_BRANCH=$1
TO_BRANCH=${2:-master}
if [[ -z $SINCE_BRANCH ]]; then
    echo "usage: changelog <since-branch> [<to-branch>]"
    exit 1
fi

CURRENT_DIR=$(PWD)
ISSUE_REGEX="#([0-9]+)"
MERGE_REGEX="Merge pull request $ISSUE_REGEX from ([^/]+)/"
ISSUES=()

shopt -s extglob

PACKAGE_PATH=$CURRENT_DIR

PACKAGE="$(basename "${PACKAGE_PATH}")"

# Checkout current tracking branch
git checkout $TO_BRANCH --quiet

# Get commits since HEAD
SINCE=$(git log --reverse $SINCE_BRANCH... | head -n 1 | awk '{print $2;}')

# Get repo name
REPO=$(basename -s .git `git config --get remote.origin.url`)

# Output heading, space separated and capitalised
NAME="${PACKAGE//-/ }"

while true; do
    # Grab the commit (this is the PR)
    IFS= read -r -d '' COMMIT;
    if [[ -z $COMMIT ]]; then
        break;
    fi

    # echo $COMMIT
    # Run the matcher
    if [[ ! $COMMIT =~ $MERGE_REGEX ]]; then
        continue
    fi

    # Grab the main PR
    PR="${BASH_REMATCH[1]}"

    # Strip the merge line
    DESCRIPTION=$(tail -n +2 <<<"$COMMIT" | grep -v "^$" | sed 's/^[ \t]*//')

    # Parse issues out
    COMMIT_ISSUES=("$PR")
    [[ $DESCRIPTION =~ $ISSUE_REGEX ]]
    COMMIT_ISSUES=($COMMIT_ISSUES ${BASH_REMATCH[@]:1})

    echo "- $DESCRIPTION humanmade/${REPO}#$PR"

done < <(git log $SINCE... --merges --reverse -z --raw --format="format:- %w(80,0,4)%B%n")