Cloning folder with related history

clone.sh

# Let's consider some demo repository contains foo folder in its
# root along with some other stuff. We want to make clone of foo
# and preserve the history of commits for the files inside it.
# The new name for the foo's clone will be bar.

# The steps

# 1. Installing required dependency https://github.com/newren/git-filter-repo
#    brew install git-filter-repo

# 2. Cloning 2 instances of the repository. The first one will be
#    using as a merge target with original history. In the second
#    one we will filter commits related to a cloning folder and
#    rename it.
git clone git@github.com:account/demo.git demo
git clone git@github.com:account/demo.git demo_with_copy_paste

# 3. Filtering history related to cloning folder and renaming it 
cd demo_with_copy_paste
git filter-repo --path foo --path-rename foo:bar

# 4. Merging repository with foo's clone named bar into original repository 
cd ../demo
git remote add demo_with_copy_paste ../demo_with_copy_paste
git fetch demo_with_copy_paste
git merge demo_with_copy_paste/master --allow-unrelated-histories