My concern is that the tutorial ignores or discards ideas essential to how git works, and what makes git different to other version control systems.
As other comments have said, this is showing 'just another SCM system' without illuminating the design decisions that make git different.
For example, in git it is extremely important that commit objects have a unique identifier for any given working directory, history, and commit meta-data. Without this guarantee the distributed architecture of git is (almost) impossible to implement.
In the commit section the tutorial states:
a simple Commit class would have ... a change containing the snapshot of change made. Understanding how a change is actually stored is beyond the scope of this implementation.
This terminology is misleading at best, and skips over a very important concept in how git actually works. The phrase 'snapshot of change made' is misleading, as a commit doesn't contain any explicit information about changes made. Instead, the staged files in the working directory are saved into a 'blob' store, a tree structure is created to represent the directory structure, and a reference to the tree is saved in the commit object. I understand that all this is outside the scope of the tutorial, however an outline of how commits work is important information for anyone trying to understand how git works. For example, the storage format is the primary reason operations in git are so fast.
Again, I like the tutorial, but if it wants to teach about git, as opposed to other version control systems, it needs to ensure the key git concepts are maintained.