This is a test repo to learn about git submodules, following steps from https://git-scm.com/book/en/v2/Git-Tools-Submodules
git submodule add https://github.com/mochajs/mocha.git
Running the git submodule add command with the URL of the repository your want to add, works similarly to git clone as by default it will create the directory with that repo's content at the same path from where you run the command. However you can add a custom path after the URL. git submodule add https://github.com/mochajs/mocha.git [PATH_TO_NEW_LOCATION_FOR_MODULE]
git status
shows that the submodule and new .gitmodules file are already staged and ready to commit to the project git.
git diff --cached mocha
shows that the project is at a particular git commit (the same commit hash from the project when it was added as a submodule)
git clone [URL_OF_MAIN_PROJECT_REPO]
is the typical command to add the project to your local computer, but it will display empty directories for the submodules. (in VS Code, it'll show an S indicator next to the directory name in the file tree).
Perhaps you've cloned the project not realizing there are submodules in it.
git submodule update --init --recursive
is what you use to download the submodule contents into their respective directories, at the same checkout point referenced in the main project. According to the docs, without the --recursive flag, it will not include the submodules within submodules
git clone [URL_OF_MAIN_PROJECT_REPO] --recurse-submodules
Will initialize and update each submodule and any nested submodules (if the submodules also have submodules)
Your local submodule is out of date with the one on the MAIN_PROJECT_REPO. git pull will not update submodule files, it will only fetch the updates. using git status will show the latest changes to the submodules