Auto update Changelog on version bump

update_changelog.sh

#!/bin/bash

# Usage: ./update_changelog.sh <previous_tag> <new_version>

set -e

PREV_TAG="$1"
NEW_VERSION="$2"

if [ -z "$PREV_TAG" ] || [ -z "$NEW_VERSION" ]; then
    echo "Usage: $0 <previous_tag> <new_version>"
    exit 1
fi

DATE=$(date +%Y-%m-%d)

echo "Generating changelog from $PREV_TAG to HEAD..."

CHANGELOG="## [$NEW_VERSION] - $DATE
"

CHANGELOG+=$(git log "$PREV_TAG"..HEAD --merges --pretty=format:"- %s" | sed 's/^/  /')

# Print to screen
echo ""
echo "------ COPY BELOW ------"
echo ""
echo "$CHANGELOG"
echo ""
echo "------ COMMIT COMMAND ------"
echo ""
echo "git commit -am \"Bump version to $NEW_VERSION

Changes:
$(git log "$PREV_TAG"..HEAD --merges --pretty=format:"- %s")
\""
echo ""
echo "------ TAG COMMAND ------"
echo ""
echo "git tag v$NEW_VERSION"
echo ""
echo "------ END ------"