Inspired by aicommmits, this script automates the creation of a GitHub pull request, identifying the branch to merge from, generating a title and body based on conventional commit guidelines, and optionally linking a JIRA ticket.

aipullrequests

#!/bin/bash

# Exit on error and uninitialized variables
set -euo pipefail

# Function to check if a command exists and instruct on installation if it doesn't
command_exists() {
  if ! command -v "$1" >/dev/null 2>&1; then
    echo "Error: $1 is not installed. Please install it to proceed."
    exit 1
  fi
}

# Check for required commands
for cmd in git gum gh mods; do
  command_exists "$cmd"
done

# Get the default branch from the specified remote repository
get_default_branch() {
  local default_branch
  default_branch=$(git remote show origin | grep 'HEAD branch' | cut -d' ' -f5)
  echo "$default_branch"
}

# Get the current Git branch
get_current_branch() {
  local current_branch
  current_branch=$(git rev-parse --abbrev-ref HEAD)
  echo "$current_branch"
}

# Get a list of local branches without slashes, with the default branch first
get_branches_without_slash() {
  local default_branch branches_without_slash current_branch="$1"
  default_branch=$(get_default_branch)

  # Get all branches, trim leading spaces, and exclude any branches with slashes or the current branch
  branches_without_slash=$(git branch --list | sed 's/^\*//; s/^[[:space:]]*//; /^[^/]*$/!d' | grep -v "^$current_branch$" | grep -v "^$default_branch$")

  # Check if branches_without_slash is empty
  if [[ -z "$branches_without_slash" ]]; then
    # If branches_without_slash is empty, only echo the default branch
    branches_without_slash="$default_branch"
  else
    # If branches_without_slash is not empty, prepend the default branch
    branches_without_slash=$(echo -e "$default_branch\n$branches_without_slash")
  fi

  echo "$branches_without_slash"
}

# Function to extract JIRA ticket number from a branch name
extract_jira_ticket_from_branch() {
  local branch_name="$1"
  # This regex looks for a pattern of 2 to 6 letters followed by a hyphen and numbers,
  # and it must be either at the start of the string or follow a non-letter character.
  local jira_ticket_pattern='(^|[^a-zA-Z])([a-zA-Z]{2,6})-([0-9]+)$'

  # Check if the branch name contains a JIRA ticket pattern
  if [[ $branch_name =~ $jira_ticket_pattern ]]; then
    # Extract the JIRA ticket prefix and number from the branch name
    local ticket_prefix="${BASH_REMATCH[2]}"
    local ticket_number="${BASH_REMATCH[3]}"

    # Convert the ticket prefix to uppercase
    ticket_prefix=$(echo "$ticket_prefix" | tr '[:lower:]' '[:upper:]')

    # Ensure that the prefix does not contain numbers and is between 2 and 6 letters
    if [[ ${#ticket_prefix} -ge 2 && ${#ticket_prefix} -le 6 ]]; then
      # Return the ticket number in uppercase
      echo "${ticket_prefix}-$ticket_number"
    else
      echo ""
    fi
  else
    echo ""
  fi
}

# Generate PR title and body
generate_pr_info() {
  local current_branch branches merge_to_branch
  current_branch=$(get_current_branch)
  branches=$(get_branches_without_slash "$current_branch")

  # Prompt the user for the branch they want to merge to, with the default as a fallback
  merge_to_branch=$(gum choose --header="Select the branch you wish to merge to:" $branches)

  local diff_output
  if ! diff_output=$(git diff "$merge_to_branch"..); then
    echo "Error obtaining git diff from branch $merge_to_branch. Exiting."
    exit 1
  fi

  local type scope pr_title_prefix pr_summary pr_body

  # Using the Conventional Commit format
  type=$(gum choose --header="Select the type of Pull Request:" "feat" "fix" "chore" "docs" "style" "refactor" "test" "revert")
  scope=$(gum input --placeholder "Scope (optional)")
  # Since the scope is optional, wrap it in parentheses if it has a value.
  [[ -n "$scope" ]] && scope="($scope)"

  local jira_ticket default_jira_ticket
  default_jira_ticket=$(extract_jira_ticket_from_branch "$current_branch")

  if [[ -n "$default_jira_ticket" ]]; then
    jira_ticket=$(gum input --header "Enter JIRA ticket number (found from branch: $default_jira_ticket)" --value "$default_jira_ticket")
  else
    jira_ticket=$(gum input --header "Enter JIRA ticket number (optional)" --placeholder "CCLRTN-1234")
  fi

  pr_title_prefix="$type$scope"

  echo "Generating Pull Request title..."
  pr_summary=$(echo "$diff_output" | mods --no-cache "create a Pull Request title. Only return the title and the first word should start with a lowercase letter.")
  pr_title="$pr_title_prefix: $pr_summary"

  echo -e "\nGenerating Pull Request body..."
  pr_body=$(echo "$diff_output" | mods --no-cache --format "create a Pull Request body. Only return the following sections in the body: summary, explanation, list of most notable changes per component. For the syntax: The format of these sections start at heading level 2." --max-tokens 650)

  # Append JIRA ticket link to the PR body if provided
  if [[ -n "$jira_ticket" ]]; then
    pr_body+=$'\n\n'                                                                                    # Append two newlines
    pr_body+="## Reference"$'\n'                                                                        # Append "## Reference" with a newline
    pr_body+="[Jira userstory link: $jira_ticket](https://alliander.atlassian.net/browse/$jira_ticket)" # Append the JIRA ticket link
  fi

  # echo "Generating a Pull Request from branch: $current_branch to: $merge_to_branch"
  gh pr create \
    --title "$pr_title" \
    --body "$pr_body" \
    --base "$merge_to_branch"
}

# Main script execution starts here
generate_pr_info "$@"