Crates named by what’s inside

Name: Git
Author: Kondasamy Jayaraman

Git keeps every version of your work as a sealed snapshot, named by its contents. A branch is just a label on one of them. Here you watch Larkspur’s price page change, split and come back together.

Start chapter 1 →See the chapters

Read as

The whole idea in one example

One new price, one new name

The saved page

blob

7b2ed05

Drill press at 189.00.

One price changed

new blob

d072bc1

Every character of the name moves.

Each name is the first seven characters of the SHA-1 hash real Git computes for those exact bytes.

How it works

Four ideas carry the module

1 Named by its contents
One new price, a whole new name
Pro Git: Git names an object by the SHA-1 checksum of a header (its type, a space, its size in bytes and a null byte) followed by its content.
Source, checked 25 October 2026
2 A chain of snapshots
Each crate names its parent
Pro Git: a commit names the top-level tree of its snapshot, its parent commits if any, the author and committer with a timestamp, then a blank line and the message.
Source, checked 25 October 2026
3 A branch is a label
A flag on a crate, nothing copied
Pro Git: a branch in Git is simply a lightweight movable pointer to one of the commits.
Source, checked 25 October 2026
4 Merges meet
One line, two answers: a person picks
Pro Git: if you changed the same part of the same file differently in the two branches, Git can’t merge them cleanly.
Source, checked 25 October 2026

The story

Larkspur’s price page, in Git

Mira and Tom edit Larkspur Supply Co.’s price page in Git; the team finds that a commit is a snapshot named by its contents and a branch is just a label. You’re on the team that brings the work together.

3: commits on main when the story starts, each named by the hash real Git gives it
2: people editing one price page
3: branches waiting to come in on Friday, one of them shared
10: plans tie for best in chapter 7

Your path

The chapters

Chapter 1
Named by its contents
How does Git name a version of a file?
Chapter 2
A chain of snapshots
What is a commit, and why can’t its past change quietly?
Chapter 3
A branch is a label
What does Git make when you make a branch?
Chapter 4
Three-way merge
How does Git combine two branches that both changed the page?
Chapter 5
Both changed it
What happens when both sides change the same line?
Chapter 6
Rewriting history
What does a rebase do to commits, and when is it unsafe?
Chapter 7
Bring three branches in
Which way and order brings all three in with no conflicts and the shortest history?