Prepend the current Git branch name and the JIRA parent issue to every commit message

prepare-commit-msg

#!/bin/bash
#
# Prepend the current branch name to every commit message.
# Prepend the parent issue from JIRA, if found.
#
# Save this to .git/hooks/prepare-commit-msg and make it exacutable:
# chmod +x .git/hooks/prepare-commit-msg
#

# Extract the current working branch
BRANCH="$(git rev-parse --abbrev-ref HEAD)"

# Prefix only JIRA style branches
if [[ ! "$BRANCH" =~ ^[A-Z]{2,} ]]; then
	echo "Notice: Skipping commit message prefixing because the current branch doesn't start with capital letters (JIRA style)."
	exit
fi

# Verify that Node.js is available
if ! command -v node >/dev/null 2>&1; then
	echo "Error: Node.js is required for parsing the JIRA REST API response."
	exit 1
fi

# Setup BASE64 auth value for JIRA authentication
JIRAAUTH=$(echo -n "USERNAME:PASSWORD" | base64)

if [ -z "$JIRAAUTH" ]; then
	echo "Error: Failed to generate the base64 authorization key."
	exit 1
fi

# Extract the commit message
MESSAGE=$(cat "$1")

# Get the issue details from JIRA REST API
ISSUEMETA=$(curl -s -X GET \
    -H "Authorization: Basic $JIRAAUTH" \
    -H "Content-Type: application/json" \
    "https://YOURSLUG.atlassian.net/rest/api/2/issue/$BRANCH")

# Use Node.js to extract the parent issue key from the API response
ISSUEPARENT=$(node -pe 'JSON.parse(process.argv[1]).fields.parent.key' "$ISSUEMETA" 2>/dev/null)

if [ -n "$ISSUEPARENT" ]; then
	# Prepend both the parent ticket and the current branch
	echo "$ISSUEPARENT>$BRANCH: $MESSAGE" > "$1"
else
	# Prepend only the current branch
	echo "$BRANCH: $MESSAGE" > "$1"
fi