Clean Code Rescue: free coding game to learn refactoring

What is Clean Code Rescue?

Skip's Snack Club code works, but nobody can read it. Over four days, name what makes each short JavaScript snippet hard to read, then ship the rewrite that is clearer and still does exactly the same thing. One rewrite only looks tidier; another quietly changes the behaviour and turns the tests red.

Clean Code Rescue is a free coding game about refactoring. Skip's Snack Club code works, but it's full of vague names, bare numbers, copy-pasted lines, functions that do everything and ifs nested inside ifs. Each round shows a short JavaScript snippet: first name what makes it hard to read, then compare three rewrites and ship one.

The catch: only one rewrite is a real refactor, clearer and with exactly the same behaviour. One only looks tidier, and one quietly changes what the code does, so the tests go red and you lose a life. Every answer explains all three versions, so you learn the habits as you play, from named constants to early returns.

At a glance

Category

Adventure

Difficulty

Medium

Play time

4–6 min

Price

Free, in your browser, sign-up optional

How to play

Name the smell

Vague names, a magic number, copy-paste, too many jobs in one function or deep nesting. +5 when you get it.

Compare three rewrites

Flip through versions A, B and C. The code was never broken: you're making it readable.

Ship the clean one

+10 for the clean refactor. One version only looks tidier (+0); one changes what the code does: the tests go red and you lose one of 3 lives.

Four chapters

Names, copy-paste, the pyramid of ifs, then a feature freeze with smaller traps. Finish with lives left for +5 per heart.

Scoring

Each snippet: +5 for naming the smell, +10 for shipping the clean rewrite. The rewrite that only looks tidier scores 0; the one that changes the behaviour turns the tests red and costs one of 3 lives.

12 snippets over four chapters. Finish with lives left for +5 per heart, up to 195 points.

What it trains

Readable code

Spotting vague names, magic numbers, copy-paste, long functions and deep nesting.

Safe refactoring

Changing the structure without changing the behaviour: every >, >= and ! has to survive the move.

Code review

Comparing three versions and explaining why one is better.

Strategy and tips

The code already works

This isn't bug hunting. You're looking for what slows a reader down, not for a crash.

Names carry meaning

count and unitPrice beat a and b. A name like data, thing or NUMBER is still vague.

Name the reason, not the value

MIN_PASSWORD_LENGTH explains 12; TWELVE doesn't.

Copy conditions exactly

When you move or flip a condition, check every > and >=, and every !.

Guard order matters

With early returns, the first check that matches wins, so keep the special cases first.

Why play Clean Code Rescue?

Code is read far more often than it is written. Refactoring, improving the structure without changing the behaviour, keeps a codebase easy to change: clear names, named numbers, one job per function, no copy-paste and flat logic. The hard part is doing it safely, and that's what the red-tests trap trains.

Frequently asked questions