Phase 1: Git for Real Work · ~35 minutes · git

Commit Hygiene and Code Review

git blame points at a commit that just says "fixes." Fixes what? Why? Six months from now, that message is the only context you'll have — and it tells you nothing.

Hiring signal: Writes commit messages for the reader six months from now, not for themselves right now

What you will learn

Write commit messages that explain what changed and why, not just restate the diff
Apply the Conventional Commits pattern
Explain what a real code review looks for beyond 'does it work'
Identify what's missing from a commit message for a future reader with zero context

Introduction

Type: Learn Languages: Git Prerequisites: Lesson 02 (Branching and Merging for Real Work) Time: ~35 minutes

Objective

Learning objectives

Write commit messages that explain what changed and why, not just restate the diff
Apply the Conventional Commits pattern
Explain what a real code review looks for beyond "does it work"
Identify what's missing from a commit message for a future reader with zero context

What you're building

Take 4 real diffs you've made in earlier labs (this course or Course 01), each currently committed with a vague message ("fix", "update", "changes", "wip" — recommit with these deliberately bad messages first if needed)
Rewrite each commit message using the Conventional Commits pattern, genuinely explaining what changed and why — not restating the diff in slightly different words
Pick one small diff (5-20 lines) and do a structured review pass on it in review_notes.txt, explicitly addressing: is the design reasonable, is anything more complex than needed, is it adequately tested, would a stranger understand it
Include, in a comment, one real example of a commit message you improved, showing both the before and after

A commit message reads: updated the file. What's missing, specifically, for a reader six months from now with zero context?

"updated the file" carries essentially zero information — it's true of every commit that has ever existed or ever will. It doesn't say which file, doesn't say what about it changed (added something? removed something? fixed a bug? changed behavior?), and doesn't say why. This is the "fixes" trap from this lesson's opening scenario in a slightly different costume — technically a commit message, functionally useless to the exact reader (future you, or a teammate) it's supposed to serve.

Unlock the full lesson

You've read the first 2 sections. The rest of this lesson covers The Problem, Check Yourself, Key Terms & Next — plus a hands-on lab, quiz, and project artifact.

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