Shallow checkout / branch switching for Unreal

checkout.sh

#!/bin/bash

# Script to fetch and checkout a shallow clone of a specific branch

# Check if a branch name was provided
if [ $# -eq 0 ]; then
    echo "Usage: $0 <branch-name>"
    exit 1
fi

# Store the provided branch name in a variable
BRANCH_NAME=$1

# Verify if the branch exists on the remote
if git ls-remote --heads origin $BRANCH_NAME | grep -q $BRANCH_NAME; then
    echo "Branch $BRANCH_NAME found on remote. Proceeding with fetch and checkout."
else
    echo "Branch $BRANCH_NAME does not exist on remote."
    exit 1
fi


# Attempt to fetch the specified branch as a shallow clone
if git fetch --depth=1 origin $BRANCH_NAME; then
    # Check if the branch already exists locally
    if git show-ref --verify --quiet refs/heads/$BRANCH_NAME; then
        # Reset the local branch to match the fetched commit
        git checkout $BRANCH_NAME
        git reset --hard FETCH_HEAD
    else
        # Create a new branch from FETCH_HEAD
        git checkout -b $BRANCH_NAME FETCH_HEAD
    fi
else
    echo "Failed to fetch the branch: $BRANCH_NAME as a shallow clone."
    exit 1
fi