notgit

notgit is a minimal reimplementation of Git written in Go i.e git but worse. It exists to understand how version control actually works under the hood. Simple, inspectable, and intentionally minimal.

---

Table of Contents

• Overview
• Features
• Libraries Used
• Project Structure
• Build and Prerequisites
• Usage
• What I Learned
• License

---

Overview

Git is everywhere. But few developers understand what happens when you type git add or git commit. notgit rebuilds those internals piece by piece using Go. The goal is not to replace Git, but to demystify it.

It focuses on the core concepts: repository, index, blob, tree, commit, and branch.

---

Features

• init - Initialize a new notgit repository
• add - Add file contents to the index
• commit - Record changes to the repository
• branch - List, create, or delete branches
• switch - Move between branches
• merge - Merge branch histories
• cat-file - Inspect raw object data
• config - Manage repository settings
• log - View commit history
• status - Show current working tree state

Use notgit [command] --help for more information about a command.

---

Libraries Used

spf13/cobra

spf13/cobra is a modern library for building command-line interfaces in Go. It provides a clean and structured way to define commands, subcommands, and flags. notgit uses Cobra to manage commands like init, add, commit, and branch. It automatically handles help text, argument parsing, and usage hints. This keeps the CLI experience consistent with tools like Git itself.

stretchr/testify

stretchr/testify is a Go testing toolkit that makes writing assertions and test cases easier. It provides packages like assert and require for clear and concise test validation. notgit uses the require package to ensure expected behavior in tests for objects, trees, commits, and repository operations. It helps maintain reliability while keeping the test code readable.

---

Project Structure

.
├── cmd/
│   └── notgit/
│       └── main.go          # CLI entry point
├── internal/
│   ├── commands/            # CLI commands (add, commit, branch, etc.)
│   ├── objects/             # Git object types (blob, tree, commit)
│   ├── repository/          # Repository logic (index, storage)
│   └── utils/               # Shared helpers (config, repo utils)
└── README.md

Each component is focused and self-contained. There is no hidden magic, just Go structs, files, and hash calculations.

---

Build and Prerequisites

Requirements

• Go 1.24.5 or higher
• A terminal
• Basic understanding of how Git works (optional but helpful)

Build

git clone https://github.com/Gr1shma/notgit.git
cd notgit
go build -o notgit ./cmd/notgit

Now run it:

./notgit

---

Usage

Initialize a repository

notgit init

Add a file

notgit add README.md

Commit changes

notgit commit -m "Initial commit"

Check status

notgit status

View logs

notgit log

For any command details:

notgit [command] --help

---

What I Learned

Building Git from scratch changes how you see software tools. You realize version control is not magic; it's structured data and smart design.

• Version control is just a set of objects linked by hashes.
• The index is a binary map connecting file paths to object hashes.
• Commits store snapshots of trees, not diffs.
• Branches are simple text files that point to commit hashes.
• Merging is graph traversal and conflict resolution.
• The simplicity of Git’s core makes its complexity justifiable.
• Go’s strong typing and file I/O model make system-level work approachable.
• Libraries like Cobra and Testify streamline CLI and testing without hiding complexity.

Rebuilding Git taught me how data models drive developer tools. It made me respect the engineering behind everyday commands we take for granted.

---

License

MIT License – see the LICENSE file.

Use it, learn from it, modify it. The goal is education, not replacement.

---

"Understanding a tool is the first step to mastering it."