TIL: Syncing with GitHub Repository Templates

GitHub allows you to create repositories from a template repository. This is useful because the template repository can include various tools and configuration specific to your type of project. One good example is the typescript-action template for GitHub Actions written in TypeScript.

However, when creating a repository from a repository template, your new repository is not a fork. Instead, it is a squashed version of the template repository with one commit and is totally unrelated to the new repository.

This is fine for most situations where you want to create a new repository as a one off and continue development from there. However, you may want to incorporate changes made to the repository template since your repository was created.

You can do this by using git merge --squash --allow-unrelated-histories. This allows you to merge the repository template as a single commit on the HEAD of your repository. If merge conflicts occur you can resolve them as with any merge.

Here is an example using my repo-template template repository.

# One time step: Add the repository template as a remote.
git remote add repo-template git@github.com:ianlewis/repo-template.git

# Fetch the latest version of the repo-template.
git fetch repo-template main

# Create a new squash merge commit.
git merge --no-edit --signoff --squash \
    --allow-unrelated-histories repo-template/main