Use branch name to automatically add Jira issue ID to the commit message.

Use the following shell script as commit-msg hook (.git/hooks/commit-msg executable file).

#!/usr/bin/env bash
# Automatically add JIRA issue ID to the git commit message

# Supported project keys
PROJECT_KEYS=(JIRA SMART BLOG)

# Commit message separator between issue number and commit message
COMMIT_MESSAGE_SEPARATOR=": "

# Get current branch
BRANCH=$(git rev-parse --abbrev-ref HEAD 2>/dev/null)
if [ "$?" -gt "0" ]; then
  exit 0
fi

# Get file with current commit message
COMMIT_MESSAGE_FILE=$1
if [ "$#" -ne "1" ] || [ ! -f "$COMMIT_MESSAGE_FILE" ]; then
  exit 1
fi

# Iterate over project key until it is found, break the loop afterwards
for PROJECT in "${PROJECT_KEYS[@]}"; do
  # Check if commit message contains project key
  # for example:
  #  "feature/SMART-1344" -> does SMART-1344 contains project key?
  echo $BRANCH | awk -F/ '{print $NF}' | grep --silent --ignore-case $PROJECT
  if [ "$?" -eq "0" ]; then
    # Extract issue id from branch name
    ISSUE="$(echo $BRANCH | awk -F/ '{print toupper($NF)}')"
    head -1 $COMMIT_MESSAGE_FILE | grep --silent --ignore-case ^${ISSUE}
    # Does it start with a task number corresponding to the branch name? (case insensitive)
    if [ "$?" -eq "0" ]; then
      # Yes, but is it uppercase?
      head -1 $COMMIT_MESSAGE_FILE | grep --silent ^${ISSUE}
      if [ "$?" -ne "0" ]; then
        sed -i "1s/^[a-Z]*/\U&\E/" $COMMIT_MESSAGE_FILE
      fi
    else
      # No, so insert issue id
      sed -i "1s/^/${ISSUE}${COMMIT_MESSAGE_SEPARATOR}/" $COMMIT_MESSAGE_FILE
    fi
    break
  fi
done

Create the initial commit – do not add an issue id.

$ git commit -m "first commit" --allow-empty
[master (root-commit) 6d28860] first commit

Create the second commit on a supported branch – add an issue id.

$ git checkout -b "SMART-5000"
Switched to a new branch 'SMART-5000'

$ git commit -m "second commit" --allow-empty
[SMART-5000 4ace356] SMART-5000: second commit

Create the third commit on a supported branch – do not add an issue id as it is already present.

$ git commit -m "SMART-5000: third commit" --allow-empty
[SMART-5000 739784f] SMART-5000: third commit

Create the fourth commit on a supported branch – do not add an issue id as it is already present, but convert the project key to uppercase.

$ git commit -m "Smart-5000: fourth commit" --allow-empty
[SMART-5000 482026b] SMART-5000: fourth commit

The main reason I wrote this blog post is that I am continually writing SMAR<strong>t</strong>-5000 and it annoys me.