git-squash-pr

#!/bin/bash
set -euf -o pipefail

# Check if the correct number of arguments are provided
if [ "$#" -ne 2 ]; then
    echo "Usage: $0 <PR-number> <origin-branch>"
    exit 1
fi

# Arguments
PR_NUMBER=$1
ORIGIN_BRANCH=$2

# Fetch the latest from the origin branch
git fetch origin $ORIGIN_BRANCH

# Check if the branch for the PR is already checked out in any worktree
if git worktree list | grep -q "pull/$PR_NUMBER"; then
    echo "PR branch 'pull/$PR_NUMBER' is already checked out in a worktree."
    exit 1
fi

# Fetch the PR head and create a local branch for it
git fetch --force origin "refs/pull/$PR_NUMBER/head:pull/$PR_NUMBER"

# Create a temporary worktree
WORKTREE_DIR=$(mktemp -d)
git worktree add "$WORKTREE_DIR" "pull/$PR_NUMBER"

# Move to the worktree
cd "$WORKTREE_DIR" || exit 1

# Function to clean up the worktree and branch on exit
cleanup() {
    # Move back to the original directory
    cd - > /dev/null
    git worktree remove "$WORKTREE_DIR" > /dev/null
    git branch -D "pull/$PR_NUMBER" > /dev/null
}
trap cleanup EXIT

# Squash all commits in the PR into a single commit with your username and email

# Get configured Git author name and email
GIT_AUTHOR_NAME=$(git config user.name)
GIT_AUTHOR_EMAIL=$(git config user.email)

COMMON_ANCESTOR=$(git merge-base "origin/$ORIGIN_BRANCH" HEAD)
echo "Common ancestor: $COMMON_ANCESTOR"
git reset --soft "$COMMON_ANCESTOR"
git commit --author="$GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL>" -m "Squashed PR #$PR_NUMBER"

# Print the new commit hash
NEW_COMMIT=$(git rev-parse HEAD)
echo "Squashed commit: $NEW_COMMIT"