git-migrate.sh

git-migrate.sh

#!/usr/bin/env bash
set -e

function usage {
    echo ''
    echo '  git migrate <repourl> <target> [branch: main]'
    echo ''
    echo '    This command is used to migrate code from the repository that'
    echo '    exists at the specified URL, at target path in repository, on'
    echo '    the specified branch. This command will preserve git history'
    echo '    for the migrated files'
    echo ''
    echo '    repourl   The url to the git repository'
    echo '              (e.g [email protected]:user/repo.git)'
    echo ''
    echo '     target   The directory in the repo to be migrated'
    echo '              (e.g path/to/migrate)'
    echo ''
    echo '     branch   The branch the desired code lives on'
    echo '              (default: c)'
    echo ''
    exit 1
}

for param in $@; do
    if [ ${param} == '-h' ]; then
        usage
    elif [ ${param} == '-help' ]; then
        usage
    elif [ ${param} == '--help' ]; then
        usage
    fi
done

if [ $# -lt 2 ]; then
    usage
fi

readonly repourl=$1
readonly target=$2
readonly current=$(pwd)

if [ $# -gt 2 ]; then
    readonly branch=$3
else
    readonly branch='main'
fi

readonly tmp=$(mktemp -d)

function on_finish {
    rm -rf ${tmp}
}
trap on_finish EXIT

git clone ${repourl} ${tmp}
cd ${tmp}
git checkout ${branch}
git remote rm origin

if [ -d ${target} ]; then
  target_dir=${target}
  target_file="*"
else
  target_dir=$(dirname ${target})
  target_file=$(basename ${target})
fi

git filter-branch --subdirectory-filter "${target_dir}" -- --all

mkdir -p ${target_dir}
set +e; mv ${target_file} ${target}; set -e

git add ${target}
git commit -m "git-migrate: Moving into proper directory"

cd ${current}
git remote add git-migrate file://${tmp}
git pull --no-edit git-migrate ${branch}
git remote rm git-migrate

git add .
git commit -m "git-migrate: Merged '${branch}' from '${repourl}' for '${target}'"